Fatma Mehar, Iqbal Noushina, Gautam Harsha, Sehar Zebus, Sofo Adriano, D'Ippolito Ilaria, Khan Nafees A
Plant Physiology and Biochemistry Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
Department of Botany, Jamia Hamdard, New Delhi 110062, India.
Plants (Basel). 2021 Jan 19;10(1):180. doi: 10.3390/plants10010180.
This study explored the interactive effect of ethephon (2-chloroethyl phosphonic acid; an ethylene source) and sulfur (S) in regulating the antioxidant system and ABA content and in maintaining stomatal responses, chloroplast structure, and photosynthetic performance of mustard plants ( L. Czern.) grown under 100 mM NaCl stress. The treatment of ethephon (200 µL L) and S (200 mg S kg soil) together markedly improved the activity of enzymatic and non-enzymatic components of the ascorbate-glutathione (AsA-GSH) cycle, resulting in declined oxidative stress through lesser content of sodium (Na) ion and hydrogen peroxide (HO) in salt-stressed plants These changes promoted the development of chloroplast thylakoids and photosynthetic performance under salt stress. Ethephon + S also reduced abscisic acid (ABA) accumulation in guard cell, leading to maximal stomatal conductance under salt stress. The inhibition of ethylene action by norbornadiene (NBD) in salt- plus non-stressed treated plants increased ABA and HO contents, and reduced stomatal opening, suggesting the involvement of ethephon and S in regulating stomatal conductance. These findings suggest that ethephon and S modulate antioxidant system and ABA accumulation in guard cells, controlling stomatal conductance, and the structure and efficiency of the photosynthetic apparatus in plants under salt stress.
本研究探讨了乙烯利（2-氯乙基膦酸；一种乙烯源）和硫（S）在调节抗氧化系统和脱落酸（ABA）含量以及维持在100 mM氯化钠胁迫下生长的芥菜（L. Czern.）气孔反应、叶绿体结构和光合性能方面的交互作用。乙烯利（200 µL L）和硫（200 mg S kg土壤）共同处理显著提高了抗坏血酸-谷胱甘肽（AsA-GSH）循环中酶促和非酶促成分的活性，通过降低盐胁迫植物中钠离子（Na）和过氧化氢（HO）的含量减轻了氧化应激。这些变化促进了盐胁迫下叶绿体类囊体的发育和光合性能。乙烯利+硫还减少了保卫细胞中脱落酸（ABA）的积累，导致盐胁迫下气孔导度最大。在盐胁迫和非胁迫处理的植物中，降冰片二烯（NBD）对乙烯作用的抑制增加了ABA和HO的含量，并减少了气孔开放，表明乙烯利和硫参与调节气孔导度。这些发现表明，乙烯利和硫调节抗氧化系统以及保卫细胞中ABA的积累，控制气孔导度以及盐胁迫下植物光合机构的结构和效率。
