Mohan Thotegowdanapalya C, Castrillo Gabriel, Navarro Cristina, Zarco-Fernández Sonia, Ramireddy Eswarayya, Mateo Cristian, Zamarreño Angel M, Paz-Ares Javier, Muñoz Riansares, García-Mina Jose M, Hernández Luis E, Schmülling Thomas, Leyva Antonio
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain (T.C.M., G.C., C.N., C.M., J.P.-A., A.L.); Department of Analytical Chemistry, School of Chemical Sciences, Universidad Complutense de Madrid, Madrid, Spain (S.Z.-F., R.M.); Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Albrecht-Thaer-Weg 6, D-14195 Berlin, Germany (E.R., T.S.); Department of Environmental Biology (Agricultural Chemistry and Biology Group), Faculty of Sciences, University of Navarra, Sciencies Building, 31008 Pamplona, Spain (A.M.Z., J.M.G.-M.); and Departamento de Biología, Universidad Autónoma de Madrid, Edif. de Biológicas BS13, Campus de Cantoblanco, 28049 Madrid, Spain (L.E.H.).
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049 Madrid, Spain (T.C.M., G.C., C.N., C.M., J.P.-A., A.L.); Department of Analytical Chemistry, School of Chemical Sciences, Universidad Complutense de Madrid, Madrid, Spain (S.Z.-F., R.M.); Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Albrecht-Thaer-Weg 6, D-14195 Berlin, Germany (E.R., T.S.); Department of Environmental Biology (Agricultural Chemistry and Biology Group), Faculty of Sciences, University of Navarra, Sciencies Building, 31008 Pamplona, Spain (A.M.Z., J.M.G.-M.); and Departamento de Biología, Universidad Autónoma de Madrid, Edif. de Biológicas BS13, Campus de Cantoblanco, 28049 Madrid, Spain (L.E.H.)
Plant Physiol. 2016 Jun;171(2):1418-26. doi: 10.1104/pp.16.00372. Epub 2016 Apr 18.
The presence of arsenic in soil and water is a constant threat to plant growth in many regions of the world. Phytohormones act in the integration of growth control and stress response, but their role in plant responses to arsenic remains to be elucidated. Here, we show that arsenate [As(V)], the most prevalent arsenic chemical species in nature, causes severe depletion of endogenous cytokinins (CKs) in the model plant Arabidopsis (Arabidopsis thaliana). We found that CK signaling mutants and transgenic plants with reduced endogenous CK levels showed an As(V)-tolerant phenotype. Our data indicate that in CK-depleted plants exposed to As(V), transcript levels of As(V)/phosphate-transporters were similar or even higher than in wild-type plants. In contrast, CK depletion provoked the coordinated activation of As(V) tolerance mechanisms, leading to the accumulation of thiol compounds such as phytochelatins and glutathione, which are essential for arsenic sequestration. Transgenic CK-deficient Arabidopsis and tobacco lines show a marked increase in arsenic accumulation. Our findings indicate that CK is an important regulatory factor in plant adaptation to arsenic stress.
土壤和水中砷的存在对世界许多地区的植物生长构成持续威胁。植物激素在生长控制和应激反应的整合中起作用，但其在植物对砷反应中的作用仍有待阐明。在这里，我们表明，自然界中最普遍的砷化学形态砷酸盐[As(V)]会导致模式植物拟南芥（Arabidopsis thaliana）中内源性细胞分裂素（CKs）严重耗竭。我们发现CK信号突变体和内源性CK水平降低的转基因植物表现出耐As(V)表型。我们的数据表明，在暴露于As(V)的CK耗竭植物中，As(V)/磷酸盐转运蛋白的转录水平与野生型植物相似甚至更高。相反，CK耗竭引发了As(V)耐受机制的协同激活，导致硫醇化合物如植物螯合肽和谷胱甘肽的积累，这些化合物对于砷的螯合至关重要。转基因CK缺陷型拟南芥和烟草品系显示砷积累显著增加。我们的研究结果表明，CK是植物适应砷胁迫的重要调节因子。
