State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
Department of Plant Pathology and Microbiology, Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX, 77843, USA.
New Phytol. 2019 Sep;223(4):1856-1872. doi: 10.1111/nph.15850. Epub 2019 Jun 28.
Salinity is among the major factors limiting crop production worldwide. Despite having moderate salt-tolerance, cotton (Gossypium spp.) suffers severe yield losses to salinity stresses, largely due to being grown on saline-alkali and dry lands. To identify genetic determinants conferring salinity tolerance in cotton, we deployed a functional genomic screen using a cotton cDNA library in a virus-induced gene silencing (VIGS) vector. We have revealed that silencing of GhDsPTP3a, which encodes a protein phosphatase, increases cotton tolerance to salt stress. Yeast two-hybrid screens indicated that GhDsPTP3a interacts with GhANN8b, an annexin protein, which plays a positive role in regulating cotton response to salinity stress. Salt stress induces GhANN8b phosphorylation, which is subsequently dephosphorylated by GhDsPTP3a. Ectopic expression of GhDsPTP3a and GhANN8b oppositely regulates plant salt tolerance and calcium influx. In addition, we have revealed that silencing of GhDsPTP3a or GhANN8b exerts opposing roles in regulating GhSOS1 transcript levels, and ectopic expression of GhANN8b elevates Na efflux in Arabidopsis under salinity stress. Our study demonstrates that a cotton phosphatase GhDsPTP3a and an annexin protein GhANN8b interact and reversely modulate Ca and Na fluxes in cotton salinity responses.
盐度是全球范围内限制作物产量的主要因素之一。尽管棉花（Gossypium spp.）具有一定的耐盐性，但由于在盐碱地和干旱地区种植，仍会受到盐胁迫的严重影响，导致产量大幅下降。为了鉴定赋予棉花耐盐性的遗传决定因素，我们使用棉花 cDNA 文库在病毒诱导的基因沉默（VIGS）载体中进行了功能基因组筛选。我们已经揭示，沉默编码蛋白磷酸酶的 GhDsPTP3a 可以提高棉花对盐胁迫的耐受性。酵母双杂交筛选表明，GhDsPTP3a 与 annexin 蛋白 GhANN8b 相互作用，GhANN8b 在调节棉花对盐胁迫的反应中发挥积极作用。盐胁迫诱导 GhANN8b 磷酸化，随后被 GhDsPTP3a 去磷酸化。GhDsPTP3a 和 GhANN8b 的异位表达相反地调节植物的耐盐性和钙离子内流。此外，我们已经揭示，沉默 GhDsPTP3a 或 GhANN8b 会在调节 GhSOS1 转录本水平方面发挥相反的作用，异位表达 GhANN8b 会在盐胁迫下提高拟南芥中的 Na 外排。我们的研究表明，棉花磷酸酶 GhDsPTP3a 和 annexin 蛋白 GhANN8b 相互作用，并在棉花盐胁迫反应中反向调节 Ca 和 Na 流。
