Expression and function of the bHLH genes ALCATRAZ and SPATULA in selected Solanaceae species

[EN] The genetic mechanisms underlying fruit development have been identified in Arabidopsis and have been comparatively studied in tomato as a representative of fleshy fruits. However, comparative expression and functional analyses on the bHLH genes downstream the genetic network, ALCATRAZ (ALC) and SPATULA (SPT), which are involved in the formation of the dehiscence zone in Arabidopsis, have not been functionally studied in the Solanaceae. Here, we perform detailed expression and functional studies of ALC/SPT homologs in Nicotiana obtusifolia with capsules, and in Capsicum annuum and Solanum lycopersicum with berries. In Solanaceae, ALC and SPT genes are expressed in leaves, and all floral organs, especially in petal margins, stamens and carpels; however, their expression changes during fruit maturation according to the fruit type. Functional analyses show that downregulation of ALC/SPT genes does not have an effect on gynoecium patterning; however, they have acquired opposite roles in petal expansion and have been co-opted in leaf pigmentation in Solanaceae. In addition, ALC/SPT genes repress lignification in time and space during fruit development in Solanaceae. Altogether, some roles of ALC and SPT genes are different between Brassicaceae and Solanaceae; while the paralogs have undergone some subfunctionalization in the former they are mostly redundant in the latter.This work was funded by COLCIENCIAS (111565842812), the iCOOP + 2016 COOPB20250 from the Centro Superior de Investigación Científica, CSIC, the ExpoSeed (H2020.MSCA-RISE-2015-691109) EU grant, the Convocatoria Programáticas 2017-16302, and the Estrategia de Sostenibilidad 2018-2019, from the Universidad de Antioquia. The authors would like to thank the group members of the Ferrándiz and Madueño Labs at IBMCP-UPV for training and help in the standardization of in situ hybridization. Finally, the authors thank Ricardo Callejas and Zulma Monsalve, from the Universidad de Antioquia, for their helpful suggestions during this research.Ortiz-Ramirez, CI.; Giraldo, MA.; Ferrandiz Maestre, C.; Pabon-Mora, N. (2019). Expression and function of the bHLH genes ALCATRAZ and SPATULA in selected Solanaceae species. The Plant Journal. 99(4):686-702. https://doi.org/10.1111/tpj.14352S686702994Golam Masu, A. S. M., Khandaker, L., Berthold, J., Gates, L., Peters, K., Delong, H., & Hossain, K. (2011). Anthocyanin, Total Polyphenols and Antioxidant Activity of Common Bean. American Journal of Food Technology, 6(5), 385-394. doi:10.3923/ajft.2011.385.394Atchley, W. R., Terhalle, W., & Dress, A. (1999). Positional Dependence, Cliques, and Predictive Motifs in the bHLH Protein Domain. Journal of Molecular Evolution, 48(5), 501-516. doi:10.1007/pl00006494Ballester, P., & Ferrándiz, C. (2017). Shattering fruits: variations on a dehiscent theme. Current Opinion in Plant Biology, 35, 68-75. doi:10.1016/j.pbi.2016.11.008Baudry, A., Heim, M. A., Dubreucq, B., Caboche, M., Weisshaar, B., & Lepiniec, L. (2004). TT2, TT8, and TTG1 synergistically specify the expression ofBANYULSand proanthocyanidin biosynthesis inArabidopsis thaliana. The Plant Journal, 39(3), 366-380. doi:10.1111/j.1365-313x.2004.02138.xBemer, M., Karlova, R., Ballester, A. R., Tikunov, Y. M., Bovy, A. G., Wolters-Arts, M., … de Maagd, R. A. (2012). The Tomato FRUITFULL Homologs TDR4/FUL1 and MBP7/FUL2 Regulate Ethylene-Independent Aspects of Fruit Ripening. The Plant Cell, 24(11), 4437-4451. doi:10.1105/tpc.112.103283Besseau, S., Hoffmann, L., Geoffroy, P., Lapierre, C., Pollet, B., & Legrand, M. (2007). Flavonoid Accumulation in Arabidopsis Repressed in Lignin Synthesis Affects Auxin Transport and Plant Growth. The Plant Cell, 19(1), 148-162. doi:10.1105/tpc.106.044495Dardick, C., & Callahan, A. M. (2014). Evolution of the fruit endocarp: molecular mechanisms underlying adaptations in seed protection and dispersal strategies. Frontiers in Plant Science, 5. doi:10.3389/fpls.2014.00284Dardick, C. D., Callahan, A. M., Chiozzotto, R., Schaffer, R. J., Piagnani, M. C., & Scorza, R. (2010). Stone formation in peach fruit exhibits spatial coordination of the lignin and flavonoid pathways and similarity to Arabidopsisdehiscence. BMC Biology, 8(1). doi:10.1186/1741-7007-8-13Dinneny, J. R., Weigel, D., & Yanofsky, M. F. (2005). A genetic framework for fruit patterning inArabidopsis thaliana. Development, 132(21), 4687-4696. doi:10.1242/dev.02062Dong, Y., Burch-Smith, T. M., Liu, Y., Mamillapalli, P., & Dinesh-Kumar, S. P. (2007). A Ligation-Independent Cloning Tobacco Rattle Virus Vector for High-Throughput Virus-Induced Gene Silencing Identifies Roles for NbMADS4-1 and -2 in Floral Development. Plant Physiology, 145(4), 1161-1170. doi:10.1104/pp.107.107391Dong, T., Hu, Z., Deng, L., Wang, Y., Zhu, M., Zhang, J., & Chen, G. (2013). A Tomato MADS-Box Transcription Factor, SlMADS1, Acts as a Negative Regulator of Fruit Ripening. PLANT PHYSIOLOGY, 163(2), 1026-1036. doi:10.1104/pp.113.224436Feller, A., Machemer, K., Braun, E. L., & Grotewold, E. (2011). Evolutionary and comparative analysis of MYB and bHLH plant transcription factors. The Plant Journal, 66(1), 94-116. doi:10.1111/j.1365-313x.2010.04459.xFerrandiz, C. (2002). Regulation of fruit dehiscence in Arabidopsis. Journal of Experimental Botany, 53(377), 2031-2038. doi:10.1093/jxb/erf082Ferrándiz, C., Liljegren, S. J., & Yanofsky, M. F. (2000). Negative Regulation of the SHATTERPROOF Genes by FRUITFULL During Arabidopsis Fruit Development. Science, 289(5478), 436-438. doi:10.1126/science.289.5478.436Fourquin, C., & Ferrándiz, C. (2012). Functional analyses of AGAMOUS family members in Nicotiana benthamiana clarify the evolution of early and late roles of C-function genes in eudicots. The Plant Journal, 71(6), 990-1001. doi:10.1111/j.1365-313x.2012.05046.xFourquin, C., & Ferrándiz, C. (2014). The essential role of NGATHA genes in style and stigma specification is widely conserved across eudicots. New Phytologist, 202(3), 1001-1013. doi:10.1111/nph.12703Fujisawa, M., Nakano, T., & Ito, Y. (2011). Identification of potential target genes for the tomato fruit-ripening regulator RIN by chromatin immunoprecipitation. BMC Plant Biology, 11(1). doi:10.1186/1471-2229-11-26Fujisawa, M., Shima, Y., Higuchi, N., Nakano, T., Koyama, Y., Kasumi, T., & Ito, Y. (2011). Direct targets of the tomato-ripening regulator RIN identified by transcriptome and chromatin immunoprecipitation analyses. Planta, 235(6), 1107-1122. doi:10.1007/s00425-011-1561-2Garceau, D. C., Batson, M. K., & Pan, I. L. (2017). Variations on a theme in fruit development: the PLE lineage of MADS-box genes in tomato (TAGL1) and other species. Planta, 246(2), 313-321. doi:10.1007/s00425-017-2725-5Girin, T., Paicu, T., Stephenson, P., Fuentes, S., Körner, E., O’Brien, M., … Østergaard, L. (2011). INDEHISCENT and SPATULA Interact to Specify Carpel and Valve Margin Tissue and Thus Promote Seed Dispersal in Arabidopsis  . The Plant Cell, 23(10), 3641-3653. doi:10.1105/tpc.111.090944Gomariz-Fernández, A., Sánchez-Gerschon, V., Fourquin, C., & Ferrándiz, C. (2017). The Role of SHI/STY/SRS Genes in Organ Growth and Carpel Development Is Conserved in the Distant Eudicot Species Arabidopsis thaliana and Nicotiana benthamiana. Frontiers in Plant Science, 8. doi:10.3389/fpls.2017.00814Gould, K. S. (2000). Functional role of anthocyanins in the leaves of Quintinia serrata A. Cunn. Journal of Experimental Botany, 51(347), 1107-1115. doi:10.1093/jexbot/51.347.1107Groszmann, M., Paicu, T., & Smyth, D. R. (2008). Functional domains of SPATULA, a bHLH transcription factor involved in carpel and fruit development in Arabidopsis. The Plant Journal, 55(1), 40-52. doi:10.1111/j.1365-313x.2008.03469.xGroszmann, M., Bylstra, Y., Lampugnani, E. R., & Smyth, D. R. (2010). Regulation of tissue-specific expression of SPATULA, a bHLH gene involved in carpel development, seedling germination, and lateral organ growth in Arabidopsis. Journal of Experimental Botany, 61(5), 1495-1508. doi:10.1093/jxb/erq015Groszmann, M., Paicu, T., Alvarez, J. P., Swain, S. M., & Smyth, D. R. (2011). SPATULA and ALCATRAZ, are partially redundant, functionally diverging bHLH genes required for Arabidopsis gynoecium and fruit development. The Plant Journal, 68(5), 816-829. doi:10.1111/j.1365-313x.2011.04732.xHorbowicz, M., Kosson, R., Grzesiuk, A., & Dębski, H. (2008). Anthocyanins of Fruits and Vegetables - Their Occurrence, Analysis and Role in Human Nutrition. Journal of Fruit and Ornamental Plant Research, 68(1), 5-22. doi:10.2478/v10032-008-0001-8Ichihashi, Y., Horiguchi, G., Gleissberg, S., & Tsukaya, H. (2009). The bHLH Transcription Factor SPATULA Controls Final Leaf Size in Arabidopsis thaliana. Plant and Cell Physiology, 51(2), 252-261. doi:10.1093/pcp/pcp184Itkin, M., Seybold, H., Breitel, D., Rogachev, I., Meir, S., & Aharoni, A. (2009). TOMATO AGAMOUS-LIKEâ 1 is a component of the fruit ripening regulatory network. The Plant Journal, 60(6), 1081-1095. doi:10.1111/j.1365-313x.2009.04064.xIto, Y., Nishizawa-Yokoi, A., Endo, M., Mikami, M., Shima, Y., Nakamura, N., … Toki, S. (2017). Re-evaluation of the rin mutation and the role of RIN in the induction of tomato ripening. Nature Plants, 3(11), 866-874. doi:10.1038/s41477-017-0041-5KAY, Q. O. N., DAOUD, H. S., & STIRTON, C. H. (1981). Pigment distribution, light reflection and cell structure in petals. Botanical Journal of the Linnean Society, 83(1), 57-83. doi:10.1111/j.1095-8339.1981.tb00129.xLiljegren, S. J., Ditta, G. S., Eshed, Y., Savidge, B., Bowman, J. L., & Yanofsky, M. F. (2000). SHATTERPROOF MADS-box genes control seed dispersal in Arabidopsis. Nature, 404(6779), 766-770. doi:10.1038/35008089Liljegren, S. J., Roeder, A. H. ., Kempin, S. A., Gremski, K., Østergaard, L., Guimil, S., … Yanofsky, M. F. (2004). Control of Fruit Patterning in Arabidopsis by INDEHISCENT. Cell, 116(6), 843-853. doi:10.1016/s0092-8674(04)00217-xLiu, E., & Page, J. E. (2008). Optimized cDNA libraries for virus-induced gene silencing (VIGS) using tobacco rattle virus. Plant Methods, 4(1), 5. doi:10.1186/1746-4811-4-5Liu, Y., Schiff, M., Marathe, R., & Dinesh-Kumar, S. P. (2002). Tobacco Rar1, EDS1 and NPR1/NIM1 like genes are required for N-mediated resistance to tobacco mosaic virus. The Plant Journal, 30(4), 415-429. doi:10.1046/j.1365-313x.2002.01297.xLivak, K. J., & Schmittgen, T. D. (2001). Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT Method. Methods, 25(4), 402-408. doi:10.1006/meth.2001.1262Nesi, N., Debeaujon, I., Jond, C., Pelletier, G., Caboche, M., & Lepiniec, L. (2000). The TT8 Gene Encodes a Basic Helix-Loop-Helix Domain Protein Required for Expression of DFR and BAN Genes in Arabidopsis Siliques. The Plant Cell, 12(10), 1863-1878. doi:10.1105/tpc.12.10.1863Ortiz-Ramírez, C. I., Plata-Arboleda, S., & Pabón-Mora, N. (2018). Evolution of genes associated with gynoecium patterning and fruit development in Solanaceae. Annals of Botany, 121(6), 1211-1230. doi:10.1093/aob/mcy007Pabón-Mora, N., & Litt, A. (2011). Comparative anatomical and developmental analysis of dry and fleshy fruits of Solanaceae. American Journal of Botany, 98(9), 1415-1436. doi:10.3732/ajb.1100097Pabón-Mora, N., Ambrose, B. A., & Litt, A. (2012). Poppy APETALA1/FRUITFULL Orthologs Control Flowering Time, Branching, Perianth Identity, and Fruit Development    . Plant Physiology, 158(4), 1685-1704. doi:10.1104/pp.111.192104Pan, I. L., McQuinn, R., Giovannoni, J. J., & Irish, V. F. (2010). Functional diversification of AGAMOUS lineage genes in regulating tomato flower and fruit development. Journal of Experimental Botany, 61(6), 1795-1806. doi:10.1093/jxb/erq046Penfield, S., Josse, E.-M., Kannangara, R., Gilday, A. D., Halliday, K. J., & Graham, I. A. (2005). Cold and Light Control Seed Germination through the bHLH Transcription Factor SPATULA. Current Biology, 15(22), 1998-2006. doi:10.1016/j.cub.2005.11.010Pires, N., & Dolan, L. (2009). Origin and Diversification of Basic-Helix-Loop-Helix Proteins in Plants. Molecular Biology and Evolution, 27(4), 862-874. doi:10.1093/molbev/msp288Rajani, S., & Sundaresan, V. (2001). The Arabidopsis myc/bHLH gene ALCATRAZ enables cell separation in fruit dehiscence. Current Biology, 11(24), 1914-1922. doi:10.1016/s0960-9822(01)00593-0Roeder, A. H. K., & Yanofsky, M. F. (2006). Fruit Development in Arabidopsis. The Arabidopsis Book, 4, e0075. doi:10.1199/tab.0075Roeder, A. H. K., Ferrándiz, C., & Yanofsky, M. F. (2003). The Role of the REPLUMLESS Homeodomain Protein in Patterning the Arabidopsis Fruit. Current Biology, 13(18), 1630-1635. doi:10.1016/j.cub.2003.08.027Schulz, M., & Weissenböck, G. (1986). Isolation and Separation of Epidermal and Mesophyll Protoplasts from Rye Primary Leaves — Tissue-Specific Characteristics of Secondary Phenolic Product Accumulation. Zeitschrift für Naturforschung C, 41(1-2), 22-27. doi:10.1515/znc-1986-1-205Seymour, G. B., Østergaard, L., Chapman, N. H., Knapp, S., & Martin, C. (2013). Fruit Development and Ripening. Annual Review of Plant Biology, 64(1), 219-241. doi:10.1146/annurev-arplant-050312-120057Smykal, P., Gennen, J., De Bodt, S., Ranganath, V., & Melzer, S. (2007). Flowering of strict photoperiodic Nicotiana varieties in non-inductive conditions by transgenic approaches. Plant Molecular Biology, 65(3), 233-242. doi:10.1007/s11103-007-9211-6Tani, E., Polidoros, A. N., & Tsaftaris, A. S. (2007). Characterization and expression analysis of FRUITFULL- and SHATTERPROOF-like genes from peach (Prunus persica) and their role in split-pit formation. Tree Physiology, 27(5), 649-659. doi:10.1093/treephys/27.5.649Tani, E., Tsaballa, A., Stedel, C., Kalloniati, C., Papaefthimiou, D., Polidoros, A., … Tsaftaris, A. (2011). The study of a SPATULA-like bHLH transcription factor expressed during peach (Prunus persica) fruit development. Plant Physiology and Biochemistry, 49(6), 654-663. doi:10.1016/j.plaphy.2011.01.020Tisza, V., Kovács, L., Balogh, A., Heszky, L., & Kiss, E. (2010). Characterization of FaSPT, a SPATULA gene encoding a bHLH transcriptional factor from the non-climacteric strawberry fruit. Plant Physiology and Biochemistry, 48(10-11), 822-826. doi:10.1016/j.plaphy.2010.08.001Van der Kooi, C. J., Elzenga, J. T. M., Staal, M., & Stavenga, D. G. (2016). How to colour a flower: on the optical principles of flower coloration. Proceedings of the Royal Society B: Biological Sciences, 283(1830), 20160429. doi:10.1098/rspb.2016.0429Vrebalov, J., Ruezinsky, D., Padmanabhan, V., White, R., Medrano, D., Drake, R., … Giovannoni, J. (2002). A MADS-Box Gene Necessary for Fruit Ripening at the Tomato Ripening-Inhibitor ( Rin ) Locus. Science, 296(5566), 343-346. doi:10.1126/science.1068181Vrebalov, J., Pan, I. L., Arroyo, A. J. M., McQuinn, R., Chung, M., Poole, M., … Irish, V. F. (2009). Fleshy Fruit Expansion and Ripening Are Regulated by the Tomato SHATTERPROOF Gene TAGL1    . The Plant Cell, 21(10), 3041-3062. doi:10.1105/tpc.109.066936Xu, W., Dubos, C., & Lepiniec, L. (2015). Transcriptional control of flavonoid biosynthesis by MYB–bHLH–WDR complexes. Trends in Plant Science, 20(3), 176-185. doi:10.1016/j.tplants.2014.12.001Zumajo-Cardona, C., Ambrose, B. A., & Pabón-Mora, N. (2017). Evolution of the SPATULA/ALCATRAZ gene lineage and expression analyses in the basal eudicot, Bocconia frutescens L. (Papaveraceae). EvoDevo, 8(1). doi:10.1186/s13227-017-0068-

Developing Student-to-Student Connectedness: An Examination of Instructors’ Humor, Nonverbal Immediacy, and Self-Disclosure in Public Speaking Courses

Students often do not look forward to enrolling in public speaking courses, and therefore, it is warranted to examine opportunities to develop a supportive peer communication climate in what is typically seen as an anxiety inducing course. The present study collected data at three points in a semester (first day, mid-semester, and end-semester) to determine if initial perceptions of student-to-student connectedness and instructors’ communication behaviors (humor, nonverbal immediacy, and self-disclosure) lead to positive increases in student-to-student connectedness over the course of a semester in public speaking classes. Changes in perceptions of student-to-student connectedness at mid- and end-semester were predicted by first day perceptions of connectedness, followed by nonverbal immediacy, and teacher humor. Also, connectedness predicted students’ affect for the course, and teacher nonverbal immediacy and humor predicted students’ affect toward the instructor. However, teacher self-disclosure (i.e., amount) was negatively linked to students’ affective learning

Star Formation in Sculptor Group Dwarf Irregular Galaxies and the Nature of "Transition" Galaxies

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