Non-Recognition-of-BTH4, an Arabidopsis Mediator Subunit Homolog, Is Necessary for Development and Response to Salicylic Acid

[EN] Salicylic acid (SA) signaling acts in defense and plant development. The only gene demonstrated to be required for the response to SA is Arabidopsis thaliana NON-EXPRESSER OF PATHOGENESIS-RELATED GENE 1 (NPR1), and npr1 mutants are insensitive to SA. By focusing on the effect of analogs of SA on plant development, we identified mutants in additional genes acting in the SA response. In this work, we describe a gene necessary for the SA Non-Recognition-of-BTH4 (NRB4). Three nrb4 alleles recovered from the screen cause phenotypes similar to the wild type in the tested conditions, except for SA-related phenotypes. Plants with NRB4 null alleles express profound insensitivity to SA, even more than npr1. NRB4 null mutants are also sterile and their growth is compromised. Plants carrying weaker nrb4 alleles are also insensitive to SA, with some quantitative differences in some phenotypes, like systemic acquired resistance or pathogen growth restriction. When weak alleles are used, NPR1 and NRB4 mutations produce an additive phenotype, but we did not find evidence of a genetic interaction in F1 nor biochemical interaction in yeast or in planta. NRB4 is predicted to be a subunit of Mediator, the ortholog of MED15 in Arabidopsis. Mechanistically, NRB4 functions downstream of NPR1 to regulate the SA response.This work was supported by the "Ministerio de Economia y Competitividad" (MINECO) of Spain (Grant BIO201018896 to P.T., a Junta de Ampliacion de Estudios-Consejo Superior de Investigaciones Cientificas Fellowship to J.V.C., and a Formacion del Personal Investigador-MINECO to A.D.) and "Generalitat Valenciana" of Spain (Grant ACOMP/2012/105 to P.T.). We appreciate the opinions and generous help of Jeff Dangl and Pablo Vera with the article as well as the revision of Philippa Borrill.Canet Perez, JV.; Dobón Alonso, A.; Tornero Feliciano, P. (2012). Non-Recognition-of-BTH4, an Arabidopsis Mediator Subunit Homolog, Is Necessary for Development and Response to Salicylic Acid. Plant Cell. 24(10):4220-4235. https://doi.org/10.1105/tpc.112.103028S42204235241

The Blade-On-Petiole genes of Arabidopsis are essential for resistance induced by methyl jasmonate

Background: NPR1 is a gene of Arabidopsis thaliana required for the perception of salicylic acid. This perception triggers a defense response and negatively regulates the perception of jasmonates. Surprisingly, the application of methyl jasmonate also induces resistance, and NPR1 is also suspected to be relevant. Since an allelic series of npr1 was recently described, the behavior of these alleles was tested in response to methyl jasmonate. Results: The response to methyl jasmonate of different npr1s alleles and NPR1 paralogs null mutants was measured by the growth of a pathogen. We have also tested the subcellular localization of some npr1s, along with the protein-protein interactions that can be measured in yeast. The localization of the protein in npr1 alleles does not affect the response to methyl jasmonate. In fact, NPR1 is not required. The genes that are required in a redundant fashion are the BOPs. The BOPs are paralogs of NPR1, and they physically interact with the TGA family of transcription factors. Conclusions: Some npr1 alleles have a phenotype in this response likely because they are affecting the interaction between BOPs and TGAs, and these two families of proteins are responsible for the resistance induced by methyl jasmonate in wild type plants.This work was supported by the "Ministerio de Economia y Competitividad" (MINECO) of Spain (grant BIO201018896 to PT, a JAE-CSIC Fellowship to JVC and a FPI-MINECO to AD) and "Generalitat Valenciana" of Spain (grant ACOMP/2012/105 to PT). Thanks to Dr. Xinnian Dong for NPR1 overexpression lines and to Dr. Ove Nilsson for BOPs overexpression lines. We appreciate the opinions and generous help of Drs. Vicente Ramirez, Pablo Vera, and Shelley Hepworth about the manuscript.Dobón Alonso, A.; Fajmonova, J.; Tornero Feliciano, P.; Canet, JV. (2012). The Blade-On-Petiole genes of Arabidopsis are essential for resistance induced by methyl jasmonate. BMC Plant Biology. 199:1-1. doi:10.1186/1471-2229-12-199S11199Ross, A. F. (1961). Systemic acquired resistance induced by localized virus infections in plants. Virology, 14(3), 340-358. doi:10.1016/0042-6822(61)90319-1López, M. A., Bannenberg, G., & Castresana, C. (2008). Controlling hormone signaling is a plant and pathogen challenge for growth and survival. Current Opinion in Plant Biology, 11(4), 420-427. doi:10.1016/j.pbi.2008.05.002Browse, J. (2009). Jasmonate Passes Muster: A Receptor and Targets for the Defense Hormone. Annual Review of Plant Biology, 60(1), 183-205. doi:10.1146/annurev.arplant.043008.092007Dong, X. (2004). NPR1, all things considered. Current Opinion in Plant Biology, 7(5), 547-552. doi:10.1016/j.pbi.2004.07.005Zhang, Y., Cheng, Y. T., Qu, N., Zhao, Q., Bi, D., & Li, X. (2006). Negative regulation of defense responses in Arabidopsis by twoNPR1paralogs. The Plant Journal, 48(5), 647-656. doi:10.1111/j.1365-313x.2006.02903.xHa, C. M. (2003). The BLADE-ON-PETIOLE 1 gene controls leaf pattern formation through the modulation of meristematic activity in Arabidopsis. Development, 130(1), 161-172. doi:10.1242/dev.00196CANET, J. V., DOBÓN, A., ROIG, A., & TORNERO, P. (2010). Structure-function analysis of npr1 alleles in Arabidopsis reveals a role for its paralogs in the perception of salicylic acid. Plant, Cell & Environment, 33(11), 1911-1922. doi:10.1111/j.1365-3040.2010.02194.xZhang, Y., Fan, W., Kinkema, M., Li, X., & Dong, X. (1999). Interaction of NPR1 with basic leucine zipper protein transcription factors that bind sequences required for salicylic acid induction of the PR-1 gene. Proceedings of the National Academy of Sciences, 96(11), 6523-6528. doi:10.1073/pnas.96.11.6523Ton, J., De Vos, M., Robben, C., Buchala, A., Métraux, J.-P., Van Loon, L. C., & Pieterse, C. M. J. (2002). Characterization ofArabidopsisenhanced disease susceptibility mutants that are affected in systemically induced resistance. The Plant Journal, 29(1), 11-21. doi:10.1046/j.1365-313x.2002.01190.xSpoel, S. H., Koornneef, A., Claessens, S. M. C., Korzelius, J. P., Van Pelt, J. A., Mueller, M. J., … Pieterse, C. M. J. (2003). NPR1 Modulates Cross-Talk between Salicylate- and Jasmonate-Dependent Defense Pathways through a Novel Function in the Cytosol. The Plant Cell, 15(3), 760-770. doi:10.1105/tpc.009159Glazebrook, J., Chen, W., Estes, B., Chang, H.-S., Nawrath, C., Metraux, J.-P., … Katagiri, F. (2003). Topology of the network integrating salicylate and jasmonate signal transduction derived from global expression phenotyping. The Plant Journal, 34(2), 217-228. doi:10.1046/j.1365-313x.2003.01717.xJohansson, A., Staal, J., & Dixelius, C. (2006). Early Responses in theArabidopsis-Verticillium longisporumPathosystem Are Dependent onNDR1, JA- and ET-Associated Signals via Cytosolic NPR1 andRFO1. Molecular Plant-Microbe Interactions, 19(9), 958-969. doi:10.1094/mpmi-19-0958Leon-Reyes, A., Spoel, S. H., De Lange, E. S., Abe, H., Kobayashi, M., Tsuda, S., … Pieterse, C. M. J. (2009). Ethylene Modulates the Role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 in Cross Talk between Salicylate and Jasmonate Signaling. Plant Physiology, 149(4), 1797-1809. doi:10.1104/pp.108.133926Ramírez, V., Van der Ent, S., García-Andrade, J., Coego, A., Pieterse, C. M., & Vera, P. (2010). OCP3 is an important modulator of NPR1-mediated jasmonic acid-dependent induced defenses in Arabidopsis. BMC Plant Biology, 10(1), 199. doi:10.1186/1471-2229-10-199Hepworth, S. R., Zhang, Y., McKim, S., Li, X., & Haughn, G. W. (2005). BLADE-ON-PETIOLE–Dependent Signaling Controls Leaf and Floral Patterning in Arabidopsis. The Plant Cell, 17(5), 1434-1448. doi:10.1105/tpc.104.030536Ha, C. M., Jun, J. H., Nam, H. G., & Fletcher, J. C. (2004). BLADE-ON-PETIOLE1 Encodes a BTB/POZ Domain Protein Required for Leaf Morphogenesis in Arabidopsis thaliana. Plant and Cell Physiology, 45(10), 1361-1370. doi:10.1093/pcp/pch201Dobón, A., Canet, J. V., Perales, L., & Tornero, P. (2011). Quantitative genetic analysis of salicylic acid perception in Arabidopsis. Planta, 234(4), 671-684. doi:10.1007/s00425-011-1436-6Zhang, X., Chen, S., & Mou, Z. (2010). Nuclear localization of NPR1 is required for regulation of salicylate tolerance, isochorismate synthase 1 expression and salicylate accumulation in Arabidopsis. Journal of Plant Physiology, 167(2), 144-148. doi:10.1016/j.jplph.2009.08.002Cao, H., Glazebrook, J., Clarke, J. D., Volko, S., & Dong, X. (1997). The Arabidopsis NPR1 Gene That Controls Systemic Acquired Resistance Encodes a Novel Protein Containing Ankyrin Repeats. Cell, 88(1), 57-63. doi:10.1016/s0092-8674(00)81858-9Lawton, K. (1995). Systemic Acquired Resistance inArabidopsisRequires Salicylic Acid but Not Ethylene. Molecular Plant-Microbe Interactions, 8(6), 863. doi:10.1094/mpmi-8-0863Nawrath, C., Heck, S., Parinthawong, N., & Métraux, J.-P. (2002). EDS5, an Essential Component of Salicylic Acid–Dependent Signaling for Disease Resistance in Arabidopsis, Is a Member of the MATE Transporter Family. The Plant Cell, 14(1), 275-286. doi:10.1105/tpc.010376Wildermuth, M. C., Dewdney, J., Wu, G., & Ausubel, F. M. (2001). Isochorismate synthase is required to synthesize salicylic acid for plant defence. Nature, 414(6863), 562-565. doi:10.1038/35107108Schwab, R., Ossowski, S., Riester, M., Warthmann, N., & Weigel, D. (2006). Highly Specific Gene Silencing by Artificial MicroRNAs in Arabidopsis. The Plant Cell, 18(5), 1121-1133. doi:10.1105/tpc.105.039834Norberg, M. (2005). The BLADE ON PETIOLE genes act redundantly to control the growth and development of lateral organs. Development, 132(9), 2203-2213. doi:10.1242/dev.01815Xie, D. (1998). COI1: An Arabidopsis Gene Required for Jasmonate-Regulated Defense and Fertility. Science, 280(5366), 1091-1094. doi:10.1126/science.280.5366.1091Dombrecht, B., Xue, G. P., Sprague, S. J., Kirkegaard, J. A., Ross, J. J., Reid, J. B., … Kazan, K. (2007). MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions in Arabidopsis. The Plant Cell, 19(7), 2225-2245. doi:10.1105/tpc.106.048017He, Y., Fukushige, H., Hildebrand, D. F., & Gan, S. (2002). Evidence Supporting a Role of Jasmonic Acid in Arabidopsis Leaf Senescence. Plant Physiology, 128(3), 876-884. doi:10.1104/pp.010843Mittal, S. (1995). Role of the Phytotoxin Coronatine in the Infection ofAmbidopsis thalianabyPseudomonas syringaepv.tomato. Molecular Plant-Microbe Interactions, 8(1), 165. doi:10.1094/mpmi-8-0165Ton, J., & Mauch-Mani, B. (2004). β-amino-butyric acid-induced resistance against necrotrophic pathogens is based on ABA-dependent priming for callose. The Plant Journal, 38(1), 119-130. doi:10.1111/j.1365-313x.2004.02028.xChang, C., Kwok, S., Bleecker, A., & Meyerowitz, E. (1993). Arabidopsis ethylene-response gene ETR1: similarity of product to two-component regulators. Science, 262(5133), 539-544. doi:10.1126/science.8211181Jun, J. H., Ha, C. M., & Fletcher, J. C. (2010). BLADE-ON-PETIOLE1 Coordinates Organ Determinacy and Axial Polarity in Arabidopsis by Directly Activating ASYMMETRIC LEAVES2. The Plant Cell, 22(1), 62-76. doi:10.1105/tpc.109.070763Zhang, Y., Tessaro, M. J., Lassner, M., & Li, X. (2003). Knockout Analysis of Arabidopsis Transcription Factors TGA2, TGA5, and TGA6 Reveals Their Redundant and Essential Roles in Systemic Acquired Resistance. The Plant Cell, 15(11), 2647-2653. doi:10.1105/tpc.014894Delaney, T. P., Friedrich, L., & Ryals, J. A. (1995). Arabidopsis signal transduction mutant defective in chemically and biologically induced disease resistance. Proceedings of the National Academy of Sciences, 92(14), 6602-6606. doi:10.1073/pnas.92.14.6602Ha, C. M., Jun, J. H., Nam, H. G., & Fletcher, J. C. (2007). BLADE-ON-PETIOLE1 and 2 Control Arabidopsis Lateral Organ Fate through Regulation of LOB Domain and Adaxial-Abaxial Polarity Genes. The Plant Cell, 19(6), 1809-1825. doi:10.1105/tpc.107.051938Xu, M., Hu, T., McKim, S. M., Murmu, J., Haughn, G. W., & Hepworth, S. R. (2010). Arabidopsis BLADE-ON-PETIOLE1 and 2 promote floral meristem fate and determinacy in a previously undefined pathway targeting APETALA1 and AGAMOUS-LIKE24. The Plant Journal, 63(6), 974-989. doi:10.1111/j.1365-313x.2010.04299.xMcKim, S. M., Stenvik, G.-E., Butenko, M. A., Kristiansen, W., Cho, S. K., Hepworth, S. R., … Haughn, G. W. (2008). The BLADE-ON-PETIOLE genes are essential for abscission zone formation in Arabidopsis. Development, 135(8), 1537-1546. doi:10.1242/dev.012807Ha, C. M., Jun, J. H., & Fletcher, J. C. (2010). Control of Arabidopsis Leaf Morphogenesis Through Regulation of the YABBY and KNOX Families of Transcription Factors. Genetics, 186(1), 197-206. doi:10.1534/genetics.110.118703Stein, E., Molitor, A., Kogel, K.-H., & Waller, F. (2008). Systemic Resistance in Arabidopsis Conferred by the Mycorrhizal Fungus Piriformospora indica Requires Jasmonic Acid Signaling and the Cytoplasmic Function of NPR1. Plant and Cell Physiology, 49(11), 1747-1751. doi:10.1093/pcp/pcn147Spoel, S. H., Mou, Z., Tada, Y., Spivey, N. W., Genschik, P., & Dong, X. (2009). Proteasome-Mediated Turnover of the Transcription Coactivator NPR1 Plays Dual Roles in Regulating Plant Immunity. Cell, 137(5), 860-872. doi:10.1016/j.cell.2009.03.038Jakoby, M., Weisshaar, B., Dröge-Laser, W., Vicente-Carbajosa, J., Tiedemann, J., Kroj, T., & Parcy, F. (2002). bZIP transcription factors in Arabidopsis. Trends in Plant Science, 7(3), 106-111. doi:10.1016/s1360-1385(01)02223-3Alonso, J. M. (2003). Genome-Wide Insertional Mutagenesis of Arabidopsis thaliana. Science, 301(5633), 653-657. doi:10.1126/science.1086391Curtis, M. D., & Grossniklaus, U. (2003). A Gateway Cloning Vector Set for High-Throughput Functional Analysis of Genes in Planta. Plant Physiology, 133(2), 462-469. doi:10.1104/pp.103.027979Ciannamea, S., Kaufmann, K., Frau, M., Tonaco, I. A. N., Petersen, K., Nielsen, K. K., … Immink, R. G. H. (2006). Protein interactions of MADS box transcription factors involved in flowering in Lolium perenne. Journal of Experimental Botany, 57(13), 3419-3431. doi:10.1093/jxb/erl144Vidal, M. (1999). Yeast forward and reverse «n»-hybrid systems. Nucleic Acids Research, 27(4), 919-929. doi:10.1093/nar/27.4.919Nakagawa, T., Kurose, T., Hino, T., Tanaka, K., Kawamukai, M., Niwa, Y., … Kimura, T. (2007). Development of series of gateway binary vectors, pGWBs, for realizing efficient construction of fusion genes for plant transformation. Journal of Bioscience and Bioengineering, 104(1), 34-41. doi:10.1263/jbb.104.34Clough, S. J., & Bent, A. F. (1998). Floral dip: a simplified method forAgrobacterium-mediated transformation ofArabidopsis thaliana. The Plant Journal, 16(6), 735-743. doi:10.1046/j.1365-313x.1998.00343.

On the way to ovules: The hormonal regulation of ovule development

[EN] This review focuses on the hormonal regulation of ovule development, especially on ovule initiation, patterning, and morphogenesis. Understanding of the genetic and molecular basis of ovule development is essential from both the scientific and economic perspective. The ovule represents an attractive system to study lateral organ development in plants, and, since ovules are the precursors of seeds, full comprehension of this process can be the key to the improvement of crops, especially those depending on high production of seeds and grains. Ovule initiation, patterning, and morphogenesis are governed by complex genetic and hormonal networks involving auxins, cytokinins, brassinosteroids, and gibberellins. These coordinate the determination of the ovule number, size, and shape through the regulation of the number of ovule primordia that arise from the placenta and/or ensuring their correct development into mature functional ovules. Here we summarize the current knowledge of how ovules are formed, paying special attention to the roles of these four plant hormones.This work was supported by the Spanish Ministry for Science and Innovation-FEDER under [grant BIO2017-83138R].Barro-Trastoy, D.; Gómez, MD.; Tornero Feliciano, P.; Perez Amador, MA. (2020). On the way to ovules: The hormonal regulation of ovule development. Critical Reviews in Plant Sciences. 39(5):431-456. https://doi.org/10.1080/07352689.2020.1820203S431456395Aida, M., & Tasaka, M. (2006). Genetic control of shoot organ boundaries. Current Opinion in Plant Biology, 9(1), 72-77. doi:10.1016/j.pbi.2005.11.011Aida, M., Ishida, T., Fukaki, H., Fujisawa, H., & Tasaka, M. (1997). Genes involved in organ separation in Arabidopsis: an analysis of the cup-shaped cotyledon mutant. The Plant Cell, 9(6), 841-857. doi:10.1105/tpc.9.6.841Armenta-Medina, A., & Gillmor, C. S. (2019). Genetic, molecular and parent-of-origin regulation of early embryogenesis in flowering plants. Plant Development and Evolution, 497-543. doi:10.1016/bs.ctdb.2018.11.008Azhakanandam, S., Nole-Wilson, S., Bao, F., & Franks, R. G. (2008). SEUSSandAINTEGUMENTAMediate Patterning and Ovule Initiation during Gynoecium Medial Domain Development    . Plant Physiology, 146(3), 1165-1181. doi:10.1104/pp.107.114751Baker, C. C., Sieber, P., Wellmer, F., & Meyerowitz, E. M. (2005). The early extra petals1 Mutant Uncovers a Role for MicroRNA miR164c in Regulating Petal Number in Arabidopsis. Current Biology, 15(4), 303-315. doi:10.1016/j.cub.2005.02.017Balasubramanian, S., & Schneitz, K. (2000). NOZZLE regulates proximal-distal pattern formation, cell proliferation and early sporogenesis during ovule development in Arabidopsis thaliana. Development, 127(19), 4227-4238. doi:10.1242/dev.127.19.4227Balasubramanian, S., & Schneitz, K. (2002). NOZZLE links proximal-distal and adaxial-abaxial pattern formation during ovule development in Arabidopsis thaliana. Development, 129(18), 4291-4300. doi:10.1242/dev.129.18.4291Bao, F., Azhakanandam, S., & Franks, R. G. (2009). SEUSSandSEUSS-LIKETranscriptional Adaptors Regulate Floral and Embryonic Development in Arabidopsis. Plant Physiology, 152(2), 821-836. doi:10.1104/pp.109.146183Barro‐Trastoy, D., Carrera, E., Baños, J., Palau‐Rodríguez, J., Ruiz‐Rivero, O., Tornero, P., … Pérez‐Amador, M. A. (2020). Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms. The Plant Journal, 102(5), 1026-1041. doi:10.1111/tpj.14684Bartrina, I., Otto, E., Strnad, M., Werner, T., & Schmülling, T. (2011). Cytokinin Regulates the Activity of Reproductive Meristems, Flower Organ Size, Ovule Formation, and Thus Seed Yield in Arabidopsis thaliana      . The Plant Cell, 23(1), 69-80. doi:10.1105/tpc.110.079079Becker, A. (2020). A molecular update on the origin of the carpel. Current Opinion in Plant Biology, 53, 15-22. doi:10.1016/j.pbi.2019.08.009Bencivenga, S., Simonini, S., Benková, E., & Colombo, L. (2012). The Transcription Factors BEL1 and SPL Are Required for Cytokinin and Auxin Signaling During Ovule Development in Arabidopsis. The Plant Cell, 24(7), 2886-2897. doi:10.1105/tpc.112.100164Benková, E., Michniewicz, M., Sauer, M., Teichmann, T., Seifertová, D., Jürgens, G., & Friml, J. (2003). Local, Efflux-Dependent Auxin Gradients as a Common Module for Plant Organ Formation. Cell, 115(5), 591-602. doi:10.1016/s0092-8674(03)00924-3BERRY, P. M., & SPINK, J. H. (2009). Understanding the effect of a triazole with anti-gibberellin activity on the growth and yield of oilseed rape (Brassica napus). The Journal of Agricultural Science, 147(3), 273-285. doi:10.1017/s0021859609008491BOUTTIER, C., & MORGAN, D. G. (1992). Ovule Development and Determination of Seed Number Per Pod in Oilseed Rape (Brassica napusL.). Journal of Experimental Botany, 43(5), 709-714. doi:10.1093/jxb/43.5.709Bowman, J. L., Smyth, D. R., & Meyerowitz, E. M. (1991). Genetic interactions among floral homeotic genes of Arabidopsis. Development, 112(1), 1-20. doi:10.1242/dev.112.1.1Brambilla, V., Battaglia, R., Colombo, M., Masiero, S., Bencivenga, S., Kater, M. M., & Colombo, L. (2007). Genetic and Molecular Interactions between BELL1 and MADS Box Factors Support Ovule Development inArabidopsis. The Plant Cell, 19(8), 2544-2556. doi:10.1105/tpc.107.051797Broadhvest, J., Baker, S. C., & Gasser, C. S. (2000). SHORT INTEGUMENTS 2 Promotes Growth During Arabidopsis Reproductive Development. Genetics, 155(2), 899-907. doi:10.1093/genetics/155.2.899Brumos, J., Robles, L. M., Yun, J., Vu, T. C., Jackson, S., Alonso, J. M., & Stepanova, A. N. (2018). Local Auxin Biosynthesis Is a Key Regulator of Plant Development. Developmental Cell, 47(3), 306-318.e5. doi:10.1016/j.devcel.2018.09.022Carter, B., Henderson, J. T., Svedin, E., Fiers, M., McCarthy, K., Smith, A., … Ogas, J. (2016). Cross-Talk Between Sporophyte and Gametophyte Generations Is Promoted by CHD3 Chromatin Remodelers in Arabidopsis thaliana. Genetics, 203(2), 817-829. doi:10.1534/genetics.115.180141Ceccato, L., Masiero, S., Sinha Roy, D., Bencivenga, S., Roig-Villanova, I., Ditengou, F. A., … Colombo, L. (2013). Maternal Control of PIN1 Is Required for Female Gametophyte Development in Arabidopsis. PLoS ONE, 8(6), e66148. doi:10.1371/journal.pone.0066148Chevalier, D., Batoux, M., Fulton, L., Pfister, K., Yadav, R. K., Schellenberg, M., & Schneitz, K. (2005). STRUBBELIG defines a receptor kinase-mediated signaling pathway regulating organ development in Arabidopsis. Proceedings of the National Academy of Sciences, 102(25), 9074-9079. doi:10.1073/pnas.0503526102Christensen, C. A., King, E. J., Jordan, J. R., & Drews, G. N. (1997). Megagametogenesis in Arabidopsis wild type and the Gf mutant. Sexual Plant Reproduction, 10(1), 49-64. doi:10.1007/s004970050067Conner, J., & Liu, Z. (2000). LEUNIG, a putative transcriptional corepressor that regulates AGAMOUS expression during flower development. Proceedings of the National Academy of Sciences, 97(23), 12902-12907. doi:10.1073/pnas.230352397Cucinotta, M., Colombo, L., & Roig-Villanova, I. (2014). Ovule development, a new model for lateral organ formation. Frontiers in Plant Science, 5. doi:10.3389/fpls.2014.00117Cucinotta, M., Di Marzo, M., Guazzotti, A., de Folter, S., Kater, M. M., & Colombo, L. (2020). Gynoecium size and ovule number are interconnected traits that impact seed yield. Journal of Experimental Botany, 71(9), 2479-2489. doi:10.1093/jxb/eraa050Cucinotta, M., Manrique, S., Cuesta, C., Benkova, E., Novak, O., & Colombo, L. (2018). CUP-SHAPED COTYLEDON1 (CUC1) and CUC2 regulate cytokinin homeostasis to determine ovule number in Arabidopsis. Journal of Experimental Botany, 69(21), 5169-5176. doi:10.1093/jxb/ery281Cucinotta, M., Manrique, S., Guazzotti, A., Quadrelli, N. E., Mendes, M. A., Benkova, E., & Colombo, L. (2016). Cytokinin response factors integrate auxin and cytokinin pathways for female reproductive organ development. Development. doi:10.1242/dev.143545Davière, J.-M., & Achard, P. (2016). A Pivotal Role of DELLAs in Regulating Multiple Hormone Signals. Molecular Plant, 9(1), 10-20. doi:10.1016/j.molp.2015.09.011Denay, G., Chahtane, H., Tichtinsky, G., & Parcy, F. (2017). A flower is born: an update on Arabidopsis floral meristem formation. Current Opinion in Plant Biology, 35, 15-22. doi:10.1016/j.pbi.2016.09.003Elliott, R. C., Betzner, A. S., Huttner, E., Oakes, M. P., Tucker, W. Q., Gerentes, D., … Smyth, D. R. (1996). AINTEGUMENTA, an APETALA2-like gene of Arabidopsis with pleiotropic roles in ovule development and floral organ growth. The Plant Cell, 8(2), 155-168. doi:10.1105/tpc.8.2.155Endress, P. K. (2011). Angiosperm ovules: diversity, development, evolution. Annals of Botany, 107(9), 1465-1489. doi:10.1093/aob/mcr120Enugutti, B., & Schneitz, K. (2013). Genetic analysis of ectopic growth suppression during planar growth of integuments mediated by the Arabidopsis AGC protein kinase UNICORN. BMC Plant Biology, 13(1), 2. doi:10.1186/1471-2229-13-2Enugutti, B., Kirchhelle, C., Oelschner, M., Torres Ruiz, R. A., Schliebner, I., Leister, D., & Schneitz, K. (2012). Regulation of planar growth by the Arabidopsis AGC protein kinase UNICORN. Proceedings of the National Academy of Sciences, 109(37), 15060-15065. doi:10.1073/pnas.1205089109Erbasol Serbes, I., Palovaara, J., & Groß-Hardt, R. (2019). Development and function of the flowering plant female gametophyte. Plant Development and Evolution, 401-434. doi:10.1016/bs.ctdb.2018.11.016Eshed, Y., Baum, S. F., Perea, J. V., & Bowman, J. L. (2001). Establishment of polarity in lateral organs of plants. Current Biology, 11(16), 1251-1260. doi:10.1016/s0960-9822(01)00392-xFavaro, R., Pinyopich, A., Battaglia, R., Kooiker, M., Borghi, L., Ditta, G., … Colombo, L. (2003). MADS-Box Protein Complexes Control Carpel and Ovule Development in Arabidopsis. The Plant Cell, 15(11), 2603-2611. doi:10.1105/tpc.015123Ferreira, L. G., de Alencar Dusi, D. M., Irsigler, A. S. T., Gomes, A. C. M. M., Mendes, M. A., Colombo, L., & de Campos Carneiro, V. T. (2017). GID1 expression is associated with ovule development of sexual and apomictic plants. Plant Cell Reports, 37(2), 293-306. doi:10.1007/s00299-017-2230-0Franks, R. G., Wang, C., Levin, J. Z., & Liu, Z. (2002). SEUSS, a member of a novel family of plant regulatory proteins, represses floral homeotic gene expression withLEUNIG. Development, 129(1), 253-263. doi:10.1242/dev.129.1.253Fridman, Y., & Savaldi-Goldstein, S. (2013). Brassinosteroids in growth control: How, when and where. Plant Science, 209, 24-31. doi:10.1016/j.plantsci.2013.04.002Friedt, W., Tu, J., & Fu, T. (2018). Academic and Economic Importance of Brassica napus Rapeseed. The Brassica napus Genome, 1-20. doi:10.1007/978-3-319-43694-4_1Gaiser, J. C., Robinson-Beers, K., & Gasser, C. S. (1995). The Arabidopsis SUPERMAN Gene Mediates Asymmetric Growth of the Outer Integument of Ovules. The Plant Cell, 7(3), 333. doi:10.2307/3869855Galbiati, F., Sinha Roy, D., Simonini, S., Cucinotta, M., Ceccato, L., Cuesta, C., … Colombo, L. (2013). An integrative model of the control of ovule primordia formation. The Plant Journal, 76(3), 446-455. doi:10.1111/tpj.12309Gallego-Giraldo, C., Hu, J., Urbez, C., Gomez, M. D., Sun, T., & Perez-Amador, M. A. (2014). Role of the gibberellin receptors GID1 during fruit-set in Arabidopsis. The Plant Journal, 79(6), 1020-1032. doi:10.1111/tpj.12603Gasser, C. S., & Skinner, D. J. (2019). Development and evolution of the unique ovules of flowering plants. Plant Development and Evolution, 373-399. doi:10.1016/bs.ctdb.2018.10.007Gifford, M. L., Dean, S., & Ingram, G. C. (2003). TheArabidopsis ACR4gene plays a role in cell layer organisation during ovule integument and sepal margin development. Development, 130(18), 4249-4258. doi:10.1242/dev.00634Goldental-Cohen, S., Israeli, A., Ori, N., & Yasuor, H. (2017). Auxin Response Dynamics During Wild-Type and entire Flower Development in Tomato. Plant and Cell Physiology, 58(10), 1661-1672. doi:10.1093/pcp/pcx102Gomez, M. D., Barro-Trastoy, D., Escoms, E., Saura-Sánchez, M., Sánchez, I., Briones-Moreno, A., … Perez-Amador, M. A. (2018). Gibberellins negatively modulate ovule number in plants. Development. doi:10.1242/dev.163865Gomez, M. D., Barro-Trastoy, D., Fuster-Almunia, C., Tornero, P., Alonso, J. M., & Perez-Amador, M. A. (2020). Gibberellin-mediated RGA-LIKE1 degradation regulates embryo sac development in Arabidopsis. Journal of Experimental Botany, 71(22), 7059-7072. doi:10.1093/jxb/eraa395Gómez, M. D., Fuster-Almunia, C., Ocaña-Cuesta, J., Alonso, J. M., & Pérez-Amador, M. A. (2019). RGL2 controls flower development, ovule number and fertility in Arabidopsis. Plant Science, 281, 82-92. doi:10.1016/j.plantsci.2019.01.014Gomez, M. D., Urbez, C., Perez-Amador, M. A., & Carbonell, J. (2011). Characterization of constricted fruit (ctf) Mutant Uncovers a Role for AtMYB117/LOF1 in Ovule and Fruit Development in Arabidopsis thaliana. PLoS ONE, 6(4), e18760. doi:10.1371/journal.pone.0018760Gomez, M. D., Ventimilla, D., Sacristan, R., & Perez-Amador, M. A. (2016). Gibberellins Regulate Ovule Integument Development by Interfering with the Transcription Factor ATS. Plant Physiology, 172(4), 2403-2415. doi:10.1104/pp.16.01231Gonçalves, B., Hasson, A., Belcram, K., Cortizo, M., Morin, H., Nikovics, K., … Arnaud, N. (2015). A conserved role forCUP-SHAPED COTYLEDONgenes during ovule development. The Plant Journal, 83(4), 732-742. doi:10.1111/tpj.12923Grobeta-Hardt, R. (2002). WUSCHEL signaling functions in interregional communication during Arabidopsis ovule development. Genes & Development, 16(9), 1129-1138. doi:10.1101/gad.225202Hashimoto, K., Miyashima, S., Sato-Nara, K., Yamada, T., & Nakajima, K. (2018). Functionally Diversified Members of the MIR165/6 Gene Family Regulate Ovule Morphogenesis in Arabidopsis thaliana. Plant and Cell Physiology, 59(5), 1017-1026. doi:10.1093/pcp/pcy042Hauser, B. A., He, J. Q., Park, S. O., & Gasser, C. S. (2000). TSO1 is a novel protein that modulates cytokinesis and cell expansion in Arabidopsis. Development, 127(10), 2219-2226. doi:10.1242/dev.127.10.2219Hedden, P., & Sponsel, V. (2015). A Century of Gibberellin Research. Journal of Plant Growth Regulation, 34(4), 740-760. doi:10.1007/s00344-015-9546-1Heisler, M. G., & Byrne, M. E. (2020). Progress in understanding the role of auxin in lateral organ development in plants. Current Opinion in Plant Biology, 53, 73-79. doi:10.1016/j.pbi.2019.10.007Heisler, M. G., Ohno, C., Das, P., Sieber, P., Reddy, G. V., Long, J. A., & Meyerowitz, E. M. (2005). Patterns of Auxin Transport and Gene Expression during Primordium Development Revealed by Live Imaging of the Arabidopsis Inflorescence Meristem. Current Biology, 15(21), 1899-1911. doi:10.1016/j.cub.2005.09.052Hibara, K., Takada, S., & Tasaka, M. (2003). CUC1 gene activates the expression of SAM-related genes to induce adventitious shoot formation. The Plant Journal, 36(5), 687-696. doi:10.1046/j.1365-313x.2003.01911.xHill, T. A., Broadhvest, J., Kuzoff, R. K., & Gasser, C. S. (2006). Arabidopsis SHORT INTEGUMENTS 2 Is a Mitochondrial DAR GTPase. Genetics, 174(2), 707-718. doi:10.1534/genetics.106.060657Huang, H.-Y., Jiang, W.-B., Hu, Y.-W., Wu, P., Zhu, J.-Y., Liang, W.-Q., … Lin, W.-H. (2013). BR Signal Influences Arabidopsis Ovule and Seed Number through Regulating Related Genes Expression by BZR1. Molecular Plant, 6(2), 456-469. doi:10.1093/mp/sss070Hwang, I., Sheen, J., & Müller, B. (2012). Cytokinin Signaling Networks. Annual Review of Plant Biology, 63(1), 353-380. doi:10.1146/annurev-arplant-042811-105503Ishida, T., Aida, M., Takada, S., & Tasaka, M. (2000). Involvement of CUP-SHAPED COTYLEDON Genes in Gynoecium and Ovule Development in Arabidopsis thaliana. Plant and Cell Physiology, 41(1), 60-67. doi:10.1093/pcp/41.1.60Jia, D., Chen, L., Yin, G., Yang, X., Gao, Z., Guo, Y., … Tang, W. (2020). Brassinosteroids regulate outer ovule integument growth in part via the control ofINNER NO OUTERby BRASSINOZOLE‐RESISTANT family transcription factors. Journal of Integrative Plant Biology, 62(8), 1093-1111. doi:10.1111/jipb.12915Jung, J.-H., & Park, C.-M. (2006). MIR166/165 genes exhibit dynamic expression patterns in regulating shoot apical meristem and floral development in Arabidopsis. Planta, 225(6), 1327-1338. doi:10.1007/s00425-006-0439-1Kelley, D. R., Arreola, A., Gallagher, T. L., & Gasser, C. S. (2012). ETTIN (ARF3) physically interacts with KANADI proteins to form a functional complex essential for integument development and polarity determination in Arabidopsis. Development, 139(6), 1105-1109. doi:10.1242/dev.067918Kelley, D. R., Skinner, D. J., & Gasser, C. S. (2009). Roles of polarity determinants in ovule development. The Plant Journal, 57(6), 1054-1064. doi:10.1111/j.1365-313x.2008.03752.xKhan, S. U., Yangmiao, J., Liu, S., Zhang, K., Khan, M. H. U., Zhai, Y., … Zhou, Y. (2019). Genome-wide association studies in the genetic dissection of ovule number, seed number, and seed weight in Brassica napus L. Industrial Crops and Products, 142, 111877. doi:10.1016/j.indcrop.2019.111877Klucher, K. M., Chow, H., Reiser, L., & Fischer, R. L. (1996). The AINTEGUMENTA gene of Arabidopsis required for ovule and female gametophyte development is related to the floral homeotic gene APETALA2. The Plant Cell, 8(2), 137-153. doi:10.1105/tpc.8.2.137Krizek, B. A. (1999). Ectopic expression ofAINTEGUMENTA inArabidopsis plants results in increased growth of floral organs. Developmental Genetics, 25(3), 224-236. doi:10.1002/(sici)1520-6408(1999)25:33.0.co;2-yKrizek, B. A., Blakley, I. C., Ho, Y., Freese, N., & Loraine, A. E. (2020). The Arabidopsis transcription factor AINTEGUMENTA orchestrates patterning genes and auxin signaling in the establishment of floral growth and form. The Plant Journal, 103(2), 752-768. doi:10.1111/tpj.14769Larsson, E., Roberts, C. J., Claes, A. R., Franks, R. G., & Sundberg, E. (2014). Polar Auxin Transport Is Essential for Medial versus Lateral Tissue Specification and Vascular-Mediated Valve Outgrowth in Arabidopsis Gynoecia. Plant Physiology, 166(4), 1998-2012. doi:10.1104/pp.114.245951Larsson, E., Vivian-Smith, A., Offringa, R., & Sundberg, E. (2017). Auxin Homeostasis in Arabidopsis Ovules Is Anther-Dependent at Maturation and Changes Dynamically upon Fertilization. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.01735Laufs, P., Peaucelle, A., Morin, H., & Traas, J. (2004). MicroRNA regulation of the CUC genes is required for boundary size control in Arabidopsis meristems. Development, 131(17), 4311-4322. doi:10.1242/dev.01320Lee, D.-K., Geisler, M., & Springer, P. S. (2009). LATERAL ORGAN FUSION1 and LATERAL ORGAN FUSION2function in lateral organ separation and axillary meristem formation in Arabidopsis. Development, 136(14), 2423-2432. doi:10.1242/dev.031971Leyser, O. (2017). Auxin Signaling. Plant Physiology, 176(1), 465-479. doi:10.1104/pp.17.00765Li, L., Qin, G., Tsuge, T., Hou, X., Ding, M., Aoyama, T., … Qu, L. (2008). SPOROCYTELESSmodulatesYUCCAexpression to regulate the development of lateral organs in Arabidopsis. New Phytologist, 179(3), 751-764. doi:10.1111/j.1469-8137.2008.02514.xLiao, S., Wang, L., Li, J., & Ruan, Y.-L. (2020). Cell Wall Invertase Is Essential for Ovule Development through Sugar Signaling Rather Than Provision of Carbon Nutrients. Plant Physiology, 183(3), 1126-1144. doi:10.1104/pp.20.00400Lieber, D., Lora, J., Schrempp, S., Lenhard, M., & Laux, T. (2011). Arabidopsis WIH1 and WIH2 Genes Act in the Transition from Somatic to Reproductive Cell Fate. Current Biology, 21(12), 1009-1017. doi:10.1016/j.cub.2011.05.015Lituiev, D. S., Krohn, N. G., Müller, B., Jackson, D., Hellriegel, B., Dresselhaus, T., & Grossniklaus, U. (2013). Theoretical and experimental evidence indicates that there is no detectable auxin gradient in the angiosperm female gametophyte. Development, 140(22), 4544-4553. doi:10.1242/dev.098301Liu, H.-H., Xiong, F., Duan, C.-Y., Wu, Y.-N., Zhang, Y., & Li, S. (2019). Importin β4 Mediates Nuclear Import of GRF-Interacting Factors to Control Ovule Development in Arabidopsis. Plant Physiology, 179(3), 1080-1092. doi:10.1104/pp.18.01135Liu, Z., Franks, R. G., & Klink, V. P. (2000). Regulation of Gynoecium Marginal Tissue Formation by LEUNIG and AINTEGUMENTA. The Plant Cell, 12(10), 1879-1891. doi:10.1105/tpc.12.10.1879Lora, J., Yang, X., & Tucker, M. R. (2019). Establishing a framework for female germline initiation in the plant ovule. Journal of Experimental Botany, 70(11), 2937-2949. doi:10.1093/jxb/erz212Mallory, A. C., Dugas, D. V., Bartel, D. P., & Bartel, B. (2004). MicroRNA Regulation of NAC-Domain Targets Is Required for Proper Formation and Separation of Adjacent Embryonic, Vegetative, and Floral Organs. Current Biology, 14(12), 1035-1046. doi:10.1016/j.cub.2004.06.022La Rosa, N. M. -d., Sotillo, B., Miskolczi, P., Gibbs, D. J., Vicente, J., Carbonero, P., … Blazquez, M. A. (2014). Large-Scale Identification of Gibberellin-Related Transcription Factors Defines Group VII ETHYLENE RESPONSE FACTORS as Functional DELLA Partners. PLANT PHYSIOLOGY, 166(2), 1022-1032. doi:10.1104/pp.114.244723Marsch-Martínez, N., & de Folter, S. (2016). Hormonal control of the development of the gynoecium. Current Opinion in Plant Biology, 29, 104-114. doi:10.1016/j.pbi.2015.12.006Matilla, A. J. (2019). Seed coat formation: its evolution and regulation. Seed Science Research, 29(4), 215-226. doi:10.1017/s0960258519000254McAbee, J. M., Hill, T. A., Skinner, D. J., Izhaki, A., Hauser, B. A., Meister, R. J., … Gasser, C. S. (2006). ABERRANT TESTA SHAPEencodes a KANADI family member, linking polarity determination to separation and growth of Arabidopsis ovule integuments. The Plant Journal, 46(3), 522-531. doi:10.1111/j.1365-313x

Specific Missense Alleles of the Arabidopsis Jasmonic Acid Co-Receptor COI1 Regulate Innate Immune Receptor Accumulation and Function

[EN] Plants utilize proteins containing nucleotide binding site (NB) and leucine-rich repeat (LRR) domains as intracellular innate immune receptors to recognize pathogens and initiate defense responses. Since mis-activation of defense responses can lead to tissue damage and even developmental arrest, proper regulation of NB-LRR protein signaling is critical. RAR1, SGT1, and HSP90 act as regulatory chaperones of pre-activation NB-LRR steady-state proteins. We extended our analysis of mutants derived from a rar1 suppressor screen and present two allelic rar1 suppressor (rsp) mutations of Arabidopsis COI1. Like all other coi1 mutations, coi1(rsp) missense mutations impair Jasmonic Acid (JA) signaling resulting in JA-insensitivity. However, unlike previously identified coi1 alleles, both coi1(rsp) alleles lack a male sterile phenotype. The coi1(rsp) mutants express two sets of disease resistance phenotypes. The first, also observed in coi1-1 null allele, includes enhanced basal defense against the virulent bacterial pathogen Pto DC3000 and enhanced effector-triggered immunity (ETI) mediated by the NB-LRR RPM1 protein in both rar1 and wild-type backgrounds. These enhanced disease resistance phenotypes depend on the JA signaling function of COI1. Additionally, the coi1(rsp) mutants showed a unique inability to properly regulate RPM1 accumulation and HR, exhibited increased RPM1 levels in rar1, and weakened RPM1-mediated HR in RAR1. Importantly, there was no change in the steady-state levels or HR function of RPM1 in coi1-1. These results suggest that the coi1(rsp) proteins regulate NB-LRR protein accumulation independent of JA signaling. Based on the phenotypic similarities and genetic interactions among coi1(rsp), sgt1b, and hsp90.2(rsp) mutants, our data suggest that COI1 affects NB-LRR accumulation via two NB-LRR co-chaperones, SGT1b and HSP90. Together, our data demonstrate a role for COI1 in disease resistance independent of JA signaling and provide a molecular link between the JA and NB-LRR signaling pathways.JLD is a Howard Hughes Medical Institute-Gordon and Betty Moore Foundation Plant Science Investigator. This work was funded by the HHMI-GBMF and by the National Science Foundation (Arabidopsis 2010 Program Grant IOS-0929410 to JLD). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.He, Y.; Chung, E.; Hubert, D.; Tornero Feliciano, P.; Dangl, J. (2012). Specific Missense Alleles of the Arabidopsis Jasmonic Acid Co-Receptor COI1 Regulate Innate Immune Receptor Accumulation and Function. PLoS Genetics. 8:1003018-1003018. doi:10.1371/journal.pgen.1003018S10030181003018

Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms

This is the peer reviewed version of the following article: Barro¿Trastoy, D., Carrera, E., Baños, J., Palau-Rodríguez, J., Ruiz-Rivero, O., Tornero, P., Alonso, J.M., López-Díaz, I., Gómez, M.D. and Pérez-Amador, M.A. (2020), Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms. Plant J, 102: 1026-1041, which has been published in final form at https://doi.org/10.1111/tpj.14684. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] Ovule primordia formation is a complex developmental process with a strong impact on the production of seeds. In Arabidopsis this process is controlled by a gene network, including components of the signalling pathways of auxin, brassinosteroids (BRs) and cytokinins. Recently, we have shown that gibberellins (GAs) also play an important role in ovule primordia initiation, inhibiting ovule formation in both Arabidopsis and tomato. Here we reveal that BRs also participate in the control of ovule initiation in tomato, by promoting an increase on ovule primordia formation. Moreover, molecular and genetic analyses of the co-regulation by GAs and BRs of the control of ovule initiation indicate that two different mechanisms occur in tomato and Arabidopsis. In tomato, GAs act downstream of BRs. BRs regulate ovule number through the downregulation of GA biosynthesis, which provokes stabilization of DELLA proteins that will finally promote ovule primordia initiation. In contrast, in Arabidopsis both GAs and BRs regulate ovule number independently of the activity levels of the other hormone. Taken together, our data strongly suggest that different molecular mechanisms could operate in different plant species to regulate identical developmental processes even, as for ovule primordia initiation, if the same set of hormones trigger similar responses, adding a new level of complexity.We wish to thank B. Janssen (Horticulture and Food Research Institute, New Zealand) for the pBJ60 shuttle vector, C. Ferrandiz and M. Colombo (IBMCP, CSIC-UPV, Valencia, Spain) for their help in the generation of 35S:ANT lines and L.E.P. Peres (Universidade de Sao Paulo, Brazil) for the tomato mutant lines. Our thanks also go to C. Fuster for technical assistance. This work was supported by grants from the Spanish Ministry of Economy and Competitiveness-FEDER (BIO2017-83138R) to MAPA and from NSF (DBI-0820755, MCB-1158181, and IOS-1444561) to JMA.Barro-Trastoy, D.; Carrera, E.; Baños, J.; Palau-Rodríguez, J.; Ruiz-Rivero, O.; Tornero Feliciano, P.; Alonso, JM.... (2020). Regulation of ovule initiation by gibberellins and brassinosteroids in tomato and Arabidopsis: two plant species, two molecular mechanisms. The Plant Journal. 102(5):1026-1041. https://doi.org/10.1111/tpj.14684S102610411025Azhakanandam, S., Nole-Wilson, S., Bao, F., & Franks, R. G. (2008). SEUSSandAINTEGUMENTAMediate Patterning and Ovule Initiation during Gynoecium Medial Domain Development    . Plant Physiology, 146(3), 1165-1181. doi:10.1104/pp.107.114751Bai, M.-Y., Shang, J.-X., Oh, E., Fan, M., Bai, Y., Zentella, R., … Wang, Z.-Y. (2012). Brassinosteroid, gibberellin and phytochrome impinge on a common transcription module in Arabidopsis. Nature Cell Biology, 14(8), 810-817. doi:10.1038/ncb2546Baker, S. C., Robinson-Beers, K., Villanueva, J. M., Gaiser, J. C., & Gasser, C. S. (1997). Interactions Among Genes Regulating Ovule Development in Arabidopsis thaliana. Genetics, 145(4), 1109-1124. doi:10.1093/genetics/145.4.1109Bartrina, I., Otto, E., Strnad, M., Werner, T., & Schmülling, T. (2011). Cytokinin Regulates the Activity of Reproductive Meristems, Flower Organ Size, Ovule Formation, and Thus Seed Yield in Arabidopsis thaliana      . The Plant Cell, 23(1), 69-80. doi:10.1105/tpc.110.079079Belkhadir, Y., & Jaillais, Y. (2015). The molecular circuitry of brassinosteroid signaling. New Phytologist, 206(2), 522-540. doi:10.1111/nph.13269Bencivenga, S., Simonini, S., Benková, E., & Colombo, L. (2012). The Transcription Factors BEL1 and SPL Are Required for Cytokinin and Auxin Signaling During Ovule Development in Arabidopsis. The Plant Cell, 24(7), 2886-2897. doi:10.1105/tpc.112.100164Brumos, J., Zhao, C., Gong, Y., Soriano, D., Patel, A. P., Perez-Amador, M. A., … Alonso, J. M. (2019). An Improved Recombineering Toolset for Plants. The Plant Cell, 32(1), 100-122. doi:10.1105/tpc.19.00431Carrera, E., Ruiz-Rivero, O., Peres, L. E. P., Atares, A., & Garcia-Martinez, J. L. (2012). Characterization of the procera Tomato Mutant Shows Novel Functions of the SlDELLA Protein in the Control of Flower Morphology, Cell Division and Expansion, and the Auxin-Signaling Pathway during Fruit-Set and Development    . Plant Physiology, 160(3), 1581-1596. doi:10.1104/pp.112.204552Carvalho, R. F., Campos, M. L., Pino, L. E., Crestana, S. L., Zsögön, A., Lima, J. E., … Peres, L. E. (2011). Convergence of developmental mutants into a single tomato model system: «Micro-Tom» as an effective toolkit for plant development research. Plant Methods, 7(1). doi:10.1186/1746-4811-7-18Chory, J., Nagpal, P., & Peto, C. A. (1991). Phenotypic and Genetic Analysis of det2, a New Mutant That Affects Light-Regulated Seedling Development in Arabidopsis. The Plant Cell, 3(5), 445. doi:10.2307/3869351Clough, S. J., & Bent, A. F. (1998). Floral dip: a simplified method forAgrobacterium-mediated transformation ofArabidopsis thaliana. The Plant Journal, 16(6), 735-743. doi:10.1046/j.1365-313x.1998.00343.xClouse, S. D. (2011). Brassinosteroid Signal Transduction: From Receptor Kinase Activation to Transcriptional Networks Regulating Plant Development. The Plant Cell, 23(4), 1219-1230. doi:10.1105/tpc.111.084475Cucinotta, M., Colombo, L., & Roig-Villanova, I. (2014). Ovule development, a new model for lateral organ formation. Frontiers in Plant Science, 5. doi:10.3389/fpls.2014.00117Cucinotta, M., Manrique, S., Guazzotti, A., Quadrelli, N. E., Mendes, M. A., Benkova, E., & Colombo, L. (2016). Cytokinin response factors integrate auxin and cytokinin pathways for female reproductive organ development. Development. doi:10.1242/dev.143545Davière, J.-M., & Achard, P. (2016). A Pivotal Role of DELLAs in Regulating Multiple Hormone Signals. Molecular Plant, 9(1), 10-20. doi:10.1016/j.molp.2015.09.011De Vleesschauwer, D., Van Buyten, E., Satoh, K., Balidion, J., Mauleon, R., Choi, I.-R., … Höfte, M. (2012). Brassinosteroids Antagonize Gibberellin- and Salicylate-Mediated Root Immunity in Rice      . Plant Physiology, 158(4), 1833-1846. doi:10.1104/pp.112.193672Dorcey, E., Urbez, C., Blázquez, M. A., Carbonell, J., & Perez-Amador, M. A. (2009). Fertilization-dependent auxin response in ovules triggers fruit development through the modulation of gibberellin metabolism in Arabidopsis. The Plant Journal, 58(2), 318-332. doi:10.1111/j.1365-313x.2008.03781.xFujioka, S., Li, J., Choi, Y. H., Seto, H., Takatsuto, S., Noguchi, T., … Sakurai, A. (1997). The Arabidopsis deetiolated2 mutant is blocked early in brassinosteroid biosynthesis. The Plant Cell, 9(11), 1951-1962. doi:10.1105/tpc.9.11.1951Galbiati, F., Sinha Roy, D., Simonini, S., Cucinotta, M., Ceccato, L., Cuesta, C., … Colombo, L. (2013). An integrative model of the control of ovule primordia formation. The Plant Journal, 76(3), 446-455. doi:10.1111/tpj.12309Gallego-Bartolome, J., Minguet, E. G., Grau-Enguix, F., Abbas, M., Locascio, A., Thomas, S. G., … Blazquez, M. A. (2012). Molecular mechanism for the interaction between gibberellin and brassinosteroid signaling pathways in Arabidopsis. Proceedings of the National Academy of Sciences, 109(33), 13446-13451. doi:10.1073/pnas.1119992109García-Hurtado, N., Carrera, E., Ruiz-Rivero, O., López-Gresa, M. P., Hedden, P., Gong, F., & García-Martínez, J. L. (2012). The characterization of transgenic tomato overexpressing gibberellin 20-oxidase reveals induction of parthenocarpic fruit growth, higher yield, and alteration of the gibberellin biosynthetic pathway. Journal of Experimental Botany, 63(16), 5803-5813. doi:10.1093/jxb/ers229Gleave, A. P. (1992). A versatile binary vector system with a T-DNA organisational structure conducive to efficient integration of cloned DNA into the plant genome. Plant Molecular Biology, 20(6), 1203-1207. doi:10.1007/bf00028910Gomez, M. D., Ventimilla, D., Sacristan, R., & Perez-Amador, M. A. (2016). Gibberellins Regulate Ovule Integument Development by Interfering with the Transcription Factor ATS. Plant Physiology, 172(4), 2403-2415. doi:10.1104/pp.16.01231He, J.-X., Gendron, J. M., Sun, Y., Gampala, S. S. L., Gendron, N., Sun, C. Q., & Wang, Z.-Y. (2005). BZR1 Is a Transcriptional Repressor with Dual Roles in Brassinosteroid Homeostasis and Growth Responses. Science, 307(5715), 1634-1638. doi:10.1126/science.1107580Huang, H.-Y., Jiang, W.-B., Hu, Y.-W., Wu, P., Zhu, J.-Y., Liang, W.-Q., … Lin, W.-H. (2013). BR Signal Influences Arabidopsis Ovule and Seed Number through Regulating Related Genes Expression by BZR1. Molecular Plant, 6(2), 456-469. doi:10.1093/mp/sss070Kurepin, L. V., Joo, S.-H., Kim, S.-K., Pharis, R. P., & Back, T. G. (2011). Interaction of Brassinosteroids with Light Quality and Plant Hormones in Regulating Shoot Growth of Young Sunflower and Arabidopsis Seedlings. Journal of Plant Growth Regulation, 31(2), 156-164. doi:10.1007/s00344-011-9227-7Li, Q.-F., Wang, C., Jiang, L., Li, S., Sun, S. S. M., & He, J.-X. (2012). An Interaction Between BZR1 and DELLAs Mediates Direct Signaling Crosstalk Between Brassinosteroids and Gibberellins in Arabidopsis. Science Signaling, 5(244). doi:10.1126/scisignal.2002908Li, X.-J., Chen, X.-J., Guo, X., Yin, L.-L., Ahammed, G. J., Xu, C.-J., … Yu, J.-Q. (2015). DWARFoverexpression induces alteration in phytohormone homeostasis, development, architecture and carotenoid accumulation in tomato. Plant Biotechnology Journal, 14(3), 1021-1033. doi:10.1111/pbi.12474Liu, Z., Franks, R. G., & Klink, V. P. (2000). Regulation of Gynoecium Marginal Tissue Formation by LEUNIG and AINTEGUMENTA. The Plant Cell, 12(10), 1879-1891. doi:10.1105/tpc.12.10.1879Marti, E. (2006). Genetic and physiological characterization of tomato cv. Micro-Tom. Journal of Experimental Botany, 57(9), 2037-2047. doi:10.1093/jxb/erj154Mizukami, Y., & Fischer, R. L. (2000). Plant organ size control: AINTEGUMENTA regulates growth and cell numbers during organogenesis. Proceedings of the National Academy of Sciences, 97(2), 942-947. doi:10.1073/pnas.97.2.942Montoya, T., Nomura, T., Yokota, T., Farrar, K., Harrison, K., Jones, J. G. D., … Bishop, G. J. (2005). Patterns of Dwarf expression and brassinosteroid accumulation in tomato reveal the importance of brassinosteroid synthesis during fruit development. The Plant Journal, 42(2), 262-269. doi:10.1111/j.1365-313x.2005.02376.xMüller, C. J., Larsson, E., Spíchal, L., & Sundberg, E. (2017). Cytokinin-Auxin Crosstalk in the Gynoecial Primordium Ensures Correct Domain Patterning. Plant Physiology, 175(3), 1144-1157. doi:10.1104/pp.17.00805Murashige, T., & Skoog, F. (1962). A Revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue Cultures. Physiologia Plantarum, 15(3), 473-497. doi:10.1111/j.1399-3054.1962.tb08052.xOlimpieri, I., Siligato, F., Caccia, R., Soressi, G. P., Mazzucato, A., Mariotti, L., & Ceccarelli, N. (2007). Tomato fruit set driven by pollination or by the parthenocarpic fruit allele are mediated by transcriptionally regulated gibberellin biosynthesis. Planta, 226(4), 877-888. doi:10.1007/s00425-007-0533-zPaz-Ares, J., & The REGIA Consortium. (2002). REGIA, An EU Project on Functional Genomics of Transcription Factors fromArabidopsis thaliana. Comparative and Functional Genomics, 3(2), 102-108. doi:10.1002/cfg.146Peng, J., Carol, P., Richards, D. E., King, K. E., Cowling, R. J., Murphy, G. P., & Harberd, N. P. (1997). The Arabidopsis GAI gene defines a signaling pathway that negatively regulates gibberellin responses . Genes & Development, 11(23), 3194-3205. doi:10.1101/gad.11.23.3194Reyes-Olalde, J. I., Zuñiga-Mayo, V. M., Chávez Montes, R. A., Marsch-Martínez, N., & de Folter, S. (2013). Inside the gynoecium: at the carpel margin. Trends in Plant Science, 18(11), 644-655. doi:10.1016/j.tplants.2013.08.002Sabelli, P. A., & Larkins, B. A. (2009). The Development of Endosperm in Grasses. Plant Physiology, 149(1), 14-26. doi:10.1104/pp.108.129437Schneitz, K., Baker, S. C., Gasser, C. S., & Redweik, A. (1998). Pattern formation and growth during floral organogenesis: HUELLENLOS and AINTEGUMENTA are required for the formation of the proximal region of the ovule primordium in Arabidopsis thaliana. Development, 125(14), 2555-2563. doi:10.1242/dev.125.14.2555Schneitz, K., Hulskamp, M., & Pruitt, R. E. (1995). Wild-type ovule development in Arabidopsis thaliana: a light microscope study of cleared whole-mount tissue. The Plant Journal, 7(5), 731-749. doi:10.1046/j.1365-313x.1995.07050731.xSeo, M., Jikumaru, Y., & Kamiya, Y. (2011). Profiling of Hormones and Related Metabolites in Seed Dormancy and Germination Studies. Methods in Molecular Biology, 99-111. doi:10.1007/978-1-61779-231-1_7Serrani, J. C., Sanjuán, R., Ruiz-Rivero, O., Fos, M., & García-Martínez, J. L. (2007). Gibberellin Regulation of Fruit Set and Growth in Tomato. Plant Physiology, 145(1), 246-257. doi:10.1104/pp.107.098335Serrani, J. C., Carrera, E., Ruiz-Rivero, O., Gallego-Giraldo, L., Peres, Lá. E. P., & García-Martínez, J. L. (2010). Inhibition of Auxin Transport from the Ovary or from the Apical Shoot Induces Parthenocarpic Fruit-Set in Tomato Mediated by Gibberellins    . Plant Physiology, 153(2), 851-862. doi:10.1104/pp.110.155424Sun, T. (2010). Gibberellin-GID1-DELLA: A Pivotal Regulatory Module for Plant Growth and Development. Plant Physiology, 154(2), 567-570. doi:10.1104/pp.110.161554Sun, T. (2011). The Molecular Mechanism and Evolution of the GA–GID1–DELLA Signaling Module in Plants. Current Biology, 21(9), R338-R345. doi:10.1016/j.cub.2011.02.036Tanaka, K., Nakamura, Y., Asami, T., Yoshida, S., Matsuo, T., & Okamoto, S. (2003). Physiological Roles of Brassinosteroids in Early Growth of Arabidopsis: Brassinosteroids Have a Synergistic Relationship with Gibberellin as well as Auxin in Light-Grown Hypocotyl Elongation. Journal of Plant Growth Regulation, 22(3), 259-271. doi:10.1007/s00344-003-0119-3Tang, Y., Liu, H., Guo, S., Wang, B., Li, Z., Chong, K., & Xu, Y. (2017). OsmiR396d Affects Gibberellin and Brassinosteroid Signaling to Regulate Plant Architecture in Rice. Plant Physiology, 176(1), 946-959. doi:10.1104/pp.17.00964Tong, H., Xiao, Y., Liu, D., Gao, S., Liu, L., Yin, Y., … Chu, C. (2014). Brassinosteroid Regulates Cell Elongation by Modulating Gibberellin Metabolism in Rice    . The Plant Cell, 26(11), 4376-4393. doi:10.1105/tpc.114.132092Truernit, E., Bauby, H., Dubreucq, B., Grandjean, O., Runions, J., Barthélémy, J., & Palauqui, J.-C. (2008). High-Resolution Whole-Mount Imaging of Three-Dimensional Tissue Organization and Gene Expression Enables the Study of Phloem Development and Structure inArabidopsis . The Plant Cell, 20(6), 1494-1503. doi:10.1105/tpc.107.056069Tursun, B., Cochella, L., Carrera, I., & Hobert, O. (2009). A Toolkit and Robust Pipeline for the Generation of Fosmid-Based Reporter Genes in C. elegans. PLoS ONE, 4(3), e4625. doi:10.1371/journal.pone.0004625Unterholzner, S. J., Rozhon, W., Papacek, M., Ciomas, J., Lange, T., Kugler, K. G., … Poppenberger, B. (2015). Brassinosteroids Are Master Regulators of Gibberellin Biosynthesis in Arabidopsis. The Plant Cell, 27(8), 2261-2272. doi:10.1105/tpc.15.00433Wang, Z.-Y., Nakano, T., Gendron, J., He, J., Chen, M., Vafeados, D., … Chory, J. (2002). Nuclear-Localized BZR1 Mediates Brassinosteroid-Induced Growth and Feedback Suppression of Brassinosteroid Biosynthesis. Developmental Cell, 2(4), 505-513. doi:10.1016/s1534-5807(02)00153-3Xiao, H., Radovich, C., Welty, N., Hsu, J., Li, D., Meulia, T., & van der Knaap, E. (2009). Integration of tomato reproductive developmental landmarks and expression profiles, and the effect of SUN on fruit shape. BMC Plant Biology, 9(1). doi:10.1186/1471-2229-9-49Xiao, Y., Liu, D., Zhang, G., Tong, H., & Chu, C. (2017). Brassinosteroids Regulate OFP1, a DLT Interacting Protein, to Modulate Plant Architecture and Grain Morphology in Rice. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.0169

Gibberellins regulate ovule number through a DELLA¿CUC2 complex in Arabidopsis

[EN] Ovule development is a key process for plant reproduction, helping to ensure correct seed production. Several molecular factors and plant hormones such as gibberellins are involved in ovule initiation and development. Gibberellins control ovule development by the destabilization of DELLA proteins, whereas DELLA activity has been shown to act as a positive factor for ovule primordia emergence. But the molecular mechanism by which DELLA acts in ovule primordia initiation remained unknown. In this study we report that DELLA proteins participate in ovule initiation by the formation of a protein complex with the CUC2 transcription factor. The DELLA protein GAI requires CUC2 to promote ovule primordia formation, through the direct GAI-CUC2 interaction in placental cells that would determine the boundary regions between ovules during pistil development. Analysis of GAI-CUC2 interaction and co-localization in the placenta supports this hypothesis. Moreover, molecular analysis identified a subset of the loci for which the GAI protein may act as a transcriptional co-regulator in a CUC2-dependent manner. The DELLA-CUC2 complex is a component of the gene regulatory network controlling ovule primordia initiation in Arabidopsis.We wish to thank Dr. N. Arnaud (INRAE-Versailles, France) for the pCUC1:CUC1-GFP and pCUC2:CUC2-VENUS lines, Dr. D. Alabadi (IBMCP, Valencia, Spain) for the 35S:YFP-M5GAI line and GAI deletions in pDEST32, and Dr. S. Prat (CNB-Madrid, Spain) for the M5-DELLA clones in pGBKT7. We also thank Ms. C. Fuster for her excellent technical assistance and the IBMCP Bioinformatics Core Service for helping in the data processing. This work was supported by grants from the Spanish Ministry of Economy and Competitiveness-FEDER (BIO2017-83138R) and Spanish Ministry of Science and Innovation-AEI (PID2020-113920RB-I00) to MAP-A; DB-T was the recipient of a pre-doctoral fellowship from the Spanish Ministry of Universities (FPU18/00331).Barro-Trastoy, D.; Gómez, MD.; Blanco-Touriñán, N.; Tornero Feliciano, P.; Perez Amador, MA. (2022). Gibberellins regulate ovule number through a DELLA-CUC2 complex in Arabidopsis. The Plant Journal. 110(1):43-57. https://doi.org/10.1111/tpj.156074357110