A cell surface arabinogalactan-peptide influences root hair cell fate

Indexación: Scopus.Root hairs (RHs) develop from specialized epidermal trichoblast cells, whereas epidermal cells that lack RHs are known as atrichoblasts. The mechanism controlling RH cell fate is only partially understood. RH cell fate is regulated by a transcription factor complex that promotes the expression of the homeodomain protein GLABRA 2 (GL2), which blocks RH development by inhibiting ROOT HAIR DEFECTIVE 6 (RHD6). Suppression of GL2 expression activates RHD6, a series of downstream TFs including ROOT HAIR DEFECTIVE 6 LIKE-4 (RSL4) and their target genes, and causes epidermal cells to develop into RHs. Brassinosteroids (BRs) influence RH cell fate. In the absence of BRs, phosphorylated BIN2 (a Type-II GSK3-like kinase) inhibits a protein complex that regulates GL2 expression. Perturbation of the arabinogalactan peptide (AGP21) in Arabidopsis thaliana triggers aberrant RH development, similar to that observed in plants with defective BR signaling. We reveal that an O-glycosylated AGP21 peptide, which is positively regulated by BZR1, a transcription factor activated by BR signaling, affects RH cell fate by altering GL2 expression in a BIN2-dependent manner. Changes in cell surface AGP disrupts BR responses and inhibits the downstream effect of BIN2 on the RH repressor GL2 in root epidermis. © 2020 The Authors. New Phytologist © 2020 New Phytologist Trusthttps://nph-onlinelibrary-wiley-com.recursosbiblioteca.unab.cl/doi/10.1111/nph.1648

Paleoenvironmental Evolution During The Holocene In The Northeast Of São Paulo State, Brazil [evolução Paleoambiental Holocênica Da Porção Nordeste Do Estado De São Paulo, Brasil]

Palynological analysis, isotopic and charcoal fragments provided information about the climate change of the last 10.250 years BP in the northeastern portion of the State of São Paulo. The samples were taken from the base of the studied trench with ages between 10.000 and 6.986 years BP. They present C4vegetation with values δ 13C around-14.3 ‰, little presence of palynomorphs, and fragments of charcoal. The interval was interpreted as the result of the predominance of a drier climate than the current in the early Holocene (that lasted until the mid Holocene), under which paleofires already occurred. From mid Holocene to the present days, the predominance of C4and C3 vegetation values to-20.86 ‰, and the increase frequency of pollen grains (as Byrsonima and Didymopanax) indicating Cerrado (Brazilian Savannah) suggest that, in the interval of 2.096 years BP until the current days, the area has been covered by a mixed vegetation composed by elements of grassland and forest, indicating a regression of the grassland associated to wetter climate, which favors the "cerradão" as cover vegetation. © 2013 by the Sociedade Brasileira de Paleontologia.162297308Barberi, M., Salgado-Labouriau, M.L., Suguio, K., Martin, L., Turq, B., Paleovegetation and Paleoclimate of Vereda de Águas Emendadas (2000) Journal of South American Earth Sciences, 13, pp. 241-254. , DF, Central do Brazil, doi:10.1016/S0895-9811(00)00022-5Behling, H., A high resolution Holocene pollen record from Lago Pires, SE Brazil: Vegetation, climate and fire history (1995) Journal of Paleolimnology, 14, pp. 253-268Bradbury, J.P., Leyden, B., Salgado-Labouriau, M.L., Lewis, W.M., Schubert, C., Late Quaternary Environmental History of Lake Valencia (1981) Venezuela, 214, pp. 1299-1305Cassino, R., Meyer, K.E.B., Morfologia de grãos de pólen e esporos de níveis holocênicos de uma vereda do Chapadão dos Gerais (Buritizeiro, Minas Gerais), Brasil (2011) Gaea-Journal of Geoscience, 7, pp. 41-70. , doi:10.4013/gaea.2011.71.04Celarino, A.L.S., (2008) Análise Granulométrica, Química E Mineralógica Dos Solos De Uma Toposequência Na Estação Ecológica De Jataí, Luis Antônio-SP, p. 57. , Trabalho de conclusão, de curso, Universidade Estadual de Campinas, Instituto de GeociênciasCunha, S.B., Geomorfologia Fluvial (1995) Geomorfologia: Uma Atualização De Bases E Conceitos, pp. 211-226. , S.B. Cunha & A.J. Guerra (eds.), Bertrand Brasil S.Ade Oliveira, P.E., (1992) A Palynological Record of the Late Quaternary Vegetational and Climatic Change In Southeastern Brazil, p. 242. , Ohio State University, Ph.D. thesisde Oliveira, P.E., Behling, H., Ledru, M.-P., Barberi, M., Bush, M., Salgado-Labouriau, M.L., Garcia, M.J., Scheel-Ybert, R., Paleovegetação e Paleoclimas do Quaternário do Brasil (2005) Holos Editora, pp. 52-69. , C.R.G. SouzaK. SuguioA.M.S. Oliveira & P.E. De Oliveira Quaternário Do Brasilde Paula, J.E., Alves, J.L.H., (2007) 897 Madeiras Nativas Do Brasil Anatomia, Dendrologia, Dendrometria, Produção E Uso, p. 107. , orto Alegre, Editora Cinco Continentes LtdaFaegri, K., Iversen, J., (1989) Textbook of Pollen Analysis, p. 328. , New York, John Wiley & SonsFerraz-Vicentini, K.R., Salgado-Labouriau, M.L., Palynological analysis of a Palm Swamp in Central Brazil (1996) Journal of South American Earth Sciences, 9, pp. 207-219. , doi:10.1016/0895-9811(96)00007-7Gouveia, S.E.M., Pessenda, L.C.R., Boulet, R., Aravena, R., Scheel-Ybert, R., Isótopos do carbono dos carvões e da matéria orgânica do solo em estudos de mudança de vegetação e clima no Quaternário e da taxa de formação de solos no Estado de São Paulo (1999) Anais Da Acadêmia Brasileira De Ciências, 71, pp. 969-980. , doi:10.1016/0895-9811(96)00007-7Kellerhals, R., Churchm, M., Bray, D.I., Classification and analysis of river processes (1976) Journal of the Hidraulies Division, 102, pp. 813-829Ledru, M.P., Late Quaternary history and evolution of the Cerrados as revealed by palynological records (2002) The Cerrados of Brazil: Ecology and Natural History of a Neotropical Savanna, pp. 33-52. , In: P.S. Oliveira & R.J. Marquis (eds.), Columbia University PressLedru, M.P., Bertaux, J., Sifeddine, A., Suguio, K., Absence of Last Glacial Maximum records in lowland tropical forests (1998) Quaternary Research, 49, pp. 233-237. , doi: 10.1006/qres.1997.1953Ledru, M.P., Campello, R.C., Landim, D., Dominguez, J.M., Martin, L., Mourguiaat, P., Sifeddine, A., Turcq, B., Late-Glacial cooling in Amazonia inferred from pollen at Lagoa do Caçó (2001) Quaternary Research, 55, pp. 47-56. , Northern Brazil, doi:10.1006/ qres.2000.2187Ledru, M.P., Mourguiaat, P., Ceccantini, G., Turcq, B., Sifeddine, A., Tropical climates in the game of two hemispheres revealed by abrupt climatic change (2002) Geology, 30, pp. 275-278. , doi:10.1130/0091-7613(2002)0300275:TCITGO2.0.CO;2Pessenda, L.C.R., Camargo, P.B., Datação radiocarbônica de amostras de interesse arqueológico e geológico por espectrometria de cintilação líquida de baixa radiação de fundo (1991) Química Nova, 14, pp. 98-103Pessenda, L.C.R., Valência, E.P.E., Camargo, P.B., Telles, E.C.C., Martinelli, C.A., Cerri, C.C., Aravena, R., Rosanski, K., Natural radiocarbon measurements in Brazilian soils developed on basic rocks (1996) Radiocarbon, 38, pp. 203-208Pessenda, L.C.R., Vidotto, E., Ribeiro, A.S., Freitas, H.A., Bendassoli, J.A., Dinâmica do ecótono floresta-campo no Sul do Estado do Amazonas no Holoceno, através de estudos isotópicos e fitossociológicos (2007) Acta Amazônica, 37, pp. 389-404Pires, J.S.R., Santos, J.E., Pires, A.M.Z.C.R., Conservação de Lagoas Marginais: Avaliação e preposição de estratégicas para um trecho do Rio Mogi Guaçu-SP (1997) Seminário regional de ecologia, 8, 1997, 1, pp. 277-283. , Brasil, Anais, São Carlos, UFSCarReimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Bertrand, C., Blackwell, P.G., Weyhenmeyer, C.E., Intcal04 Terrestrial Radiocarbon age Calibration, 0-26 Cal KYR BP (2004) Radiocarbon, 46, pp. 1029-1058Salgado-Labouriau, M.L., Reconstrucción del ambiente através de los granos de polen (1984) Investigación Y Ciencia, 96, pp. 6-17Salgado-Labouriau, M.L., Late Quaternary Paleoclimate in the savannas of SouthAmérica (1997) Journal of Quaternary Sciences, 12, pp. 371-. , doi:10.1002/(SICI)1099-1417(199709/10)12:53.0.CO;2-3Salgado-Labouriau, M.L., (2007) Critérios E Técnicas Para O Quaternário, p. 404. , São Paulo, Editora BlücherSalgado-Labouriau, M.L., Casseti, V., Ferraz-Vicentini, K.R., Martin, L., Soubiès, F., Suguio, K., Turcq, B., Late Quaternary vegetational and climatic changes in Cerrado and palm swamp from Central Brazil. Palaeogeography (1997) Palaeoclimatology, Palaeoecology, 128, pp. 215-226. , doi:10.1016/ S0031-0182(96)00018-1Salgado-Labouriau, M.L., Ferraz-Vicentini, K.R., Fire in Cerrado 32000 years ago (1994) Current Research In the Pleistocene, 11, pp. 85-87Scheel-Ybert, R., Gouveia, S.E.M., Pessenda, L.C.R., Aravena, R., Coutinho, L.M., Boulet, R., Holocene palaeoenvironmental evolution in the São Paulo State (Brazil), based on anthracology and soil 13C analysis (2003) The Holocene, 13, pp. 73-81. , doi: 10.1191/0959683603hl596rpToppa, R.H., (2004) Estrutura E Diversidade Florística Das Diferentes Fisionomias De Cerrado E Suas Correlações Com O Solo Na Estação Ecológica De Jataí, Luiz Antônio, SP. Programa De Pós-Graduação Em Ecologia E Ecologia E Recursos Naturais, p. 149. , Universidade Federal de São Paulo, Tese de DoutoradoVidotto, E., (2003) Estudo Da Dinâmica Do Ecótono Floresta-campo No Sul Do Estado Do Amazonas No Quaternário Tardio, Empregando Os Isótopos Do Carbono Do Solo E Das Plantas, p. 101. , Centro de Energia Nuclear de Agricultura, Dissertação de Mestrad

Nuclear import and dimerization of tomato ASR1, a water stress-inducible protein exclusive to plants

The ASR (for ABA/water stress/ripening) protein family, first described in tomato as nuclear and involved in adaptation to dry climates, is widespread in the plant kingdom, including crops of high agronomic relevance. We show both nuclear and cytosolic localization for ASR1 (the most studied member of the family) in histological plant samples by immunodetection, typically found in small proteins readily diffusing through nuclear pores. Indeed, a nuclear localization was expected based on sorting prediction software, which also highlight a monopartite nuclear localization signal (NLS) in the primary sequence. However, here we prove that such an "NLS" of ASR1 from tomato is dispensable and non-functional, being the transport of the protein to the nucleus due to simple diffusion across nuclear pores. We attribute such a targeting deficiency to the misplacing in that cryptic NLS of two conserved contiguous lysine residues. Based on previous in vitro experiments regarding quaternary structure, we also carried out live cell imaging assays through confocal microscopy to explore dimer formation in planta. We found homodimers in both the cytosol and the nucleus and demonstrated that assembly of both subunits together can occur in the cytosol, giving rise to translocation of preformed dimers. The presence of dimers was further corroborated by means of in vivo crosslinking of nuclei followed by SDS-PAGE. © 2012 Ricardi et al.Fil:Ricardi, M.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:González, R.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Jares-Erijman, E.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Iusem, N.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina