Silicon and Gibberellins: Synergistic Function in Harnessing ABA Signaling and Heat Stress Tolerance in Date Palm (Phoenix dactyliferaL.)
Silicon and Gibberellins: Synergistic Function in Harnessing ABA Signaling and Heat Stress Tolerance in Date Palm (Phoenix dactyliferaL.)
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DOI：
10.3390/plants9050620
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发表时间：
2020-05-01
期刊：
影响因子：
4.5
通讯作者：
Lee, In-Jung
中科院分区：
文献类型：
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作者：
Khan, Adil;Bilal, Saqib;Lee, In-Jung
枣树是包括阿曼在内的北非和中东国家最重要的经济果树之一。采用对照试验研究了硅(Si)和赤霉酸(GA(3))对枣树生长和高温胁迫的综合效应。外源施硅和GA(3)显著促进了高温胁迫(44℃+/-1℃)下植株的生长。研究了激素调节(脱落酸[ABA]和水杨酸[SA])、抗氧化剂积累和非生物胁迫相关基因的表达。有趣的是，与单独使用相比，硅和GA(3)的综合作用显著降低了热诱导的氧化应激，显著减少了超氧阴离子和脂质过氧化。氧化胁迫的减轻归因于多酚氧化酶、过氧化氢酶、过氧化物酶和抗坏血酸过氧化物酶活性的提高以及它们的合成相关基因GPX2、CAT、Cyt-Cu/Zn-SOD和甘油醛3-磷酸脱氢酶(GAPDH)的表达上调。结果表明，与对照相比，外源Si和GA(3)能激活热激因子相关基因(尤其是HsfA3)。此外，Si和GA(3)联合处理显著减少了ABA信号相关基因(PYL4、PYL8和PYR1)的转录积累，导致ABA的产生减少，进而通过增加其积累而产生SA拮抗作用。这些发现表明，Si和GA(3)的联合应用促进了植物的生长和代谢调节，增强了对胁迫的耐受性，并为可持续粮食安全的绿色革命提供了新的胁迫缓解策略。
Date palm is one of the most economically vital fruit crops in North African and Middle East countries, including Oman. A controlled experiment was conducted to investigate the integrative effects of silicon (Si) and gibberellic acid (GA(3)) on date palm growth and heat stress. The exogenous application of Si and GA(3)significantly promoted plant growth attributes under heat stress (44 +/- 1 degrees C). The hormonal modulation (abscisic acid [ABA] and salicylic acid [SA]), antioxidant accumulation, and the expression of abiotic stress-related genes were evaluated. Interestingly, heat-induced oxidative stress was markedly reduced by the integrative effects of Si and GA(3)when compared to their sole application, with significant reductions in superoxide anions and lipid peroxidation. The reduction of oxidative stress was attributed to the enhancement of polyphenol oxidase, catalase, peroxidase, and ascorbate peroxidase activities as well as the upregulation of their synthesis related genes expression viz.GPX2,CAT,Cyt-Cu/Zn SOD, andglyceraldehyde3-phosphate dehydrogenasegene (GAPDH). The results showed the activation of heat shock factor related genes (especiallyHsfA3) during exogenous Si and GA(3)as compared to the control. Furthermore, the transcript accumulation of ABA signaling-related genes (PYL4,PYL8, andPYR1) were significantly reduced with the combined treatment of Si and GA(3), leading to reduced production of ABA and, subsequently, SA antagonism via its increased accumulation. These findings suggest that the combined application of Si and GA(3)facilitate plant growth and metabolic regulation, impart tolerance against stress, and offers novel stress alleviating strategies for a green revolution in sustainable food security.