Department of Biology and Geology, Agri-Food Campus of International Excellence (CeiA3) and Research Center CIAMBITAL, University of Almería, 04120 Almería, Spain.
Int J Mol Sci. 2024 Aug 10;25(16):8728. doi: 10.3390/ijms25168728.
The crosstalk of phytohormones in the regulation of growth and development and the response of plants to environmental stresses is a cutting-edge research topic, especially in crop species. In this paper, we study the role and crosstalk between abscisic acid (ABA), ethylene (ET), and jasmonate (JA) in the control of germination and seedling growth in water or in standard nutrient solution and under salt stress (supplemented with 100-200 mM NaCl). The roles of ET and JA were studied using squash ET- and JA-deficient mutants and , respectively, while the crosstalk between ET, JA, and ABA was determined by comparing the expression of the key ABA, JA, and ET genes in wild-type (WT) and mutant genotypes under standard conditions and salt stress. Data showed that ET and JA are positive regulators of squash germination, a function that was found to be mediated by downregulating the ABA biosynthesis and signaling pathways. Under salt stress, germinated earlier than WT, while showed the same germination rate as WT, indicating that ET, but not JA, restricts squash germination under unfavorable salinity conditions, a function that was also mediated by upregulation of ABA. ET and JA were found to be negative regulators of plant growth during seedling establishment, although ET inhibits both the aerial part and the root, while JA inhibits only the root. Both and mutant roots showed increased tolerance to salt stress, a phenotype that was found to be mainly mediated by JA, although we cannot exclude that it is also mediated by ABA.
植物激素在生长发育调控和植物对环境胁迫响应中的串扰是一个前沿研究课题，特别是在作物物种中。在本文中，我们研究了脱落酸（ABA）、乙烯（ET）和茉莉酸（JA）在控制水分或标准养分溶液中以及盐胁迫下（补充 100-200mM NaCl）萌发和幼苗生长中的作用和串扰。使用南瓜 ET 和 JA 缺陷突变体 和 分别研究了 ET 和 JA 的作用，而 ET、JA 和 ABA 之间的串扰则通过比较标准条件和盐胁迫下野生型（WT）和突变基因型中关键的 ABA、JA 和 ET 基因的表达来确定。数据表明，ET 和 JA 是南瓜萌发的正调节剂，这一功能是通过下调 ABA 生物合成和信号通路来介导的。在盐胁迫下， 比 WT 更早萌发，而 与 WT 具有相同的萌发率，表明 ET，而不是 JA，在不利的盐条件下限制了南瓜的萌发，这一功能也是通过上调 ABA 来介导的。ET 和 JA 被发现是幼苗建立过程中植物生长的负调节剂，尽管 ET 抑制地上部分和根，而 JA 仅抑制根。 和 突变体的根都表现出对盐胁迫的耐受性增加，这种表型主要是由 JA 介导的，尽管我们不能排除它也由 ABA 介导。
