Abstract：
Drought stress caused by the global climate considerably disturbs plant yield and growth. Here, we explored the putative roles of silicon in repressing drought mechanisms in pepper and the prominent involvement of secondary metabolites, GA pathway, and photosystem II. Our research revealed that the transcript level of the flavonoid biosynthesis-associated genes, including the PAL, 4-CL, CHS, FLS-1, F3H and DFR, progressively induced in the pepper leaves treated with silicon during the drought stress duration. Moreover, the phenolic and flavonoid compounds extensively induced in the pepper plants. Furthermore, the pepper plants markedly inhibited chlorophyll catabolic-allied genes, senescence-related marker gene, and the Rbohs gene. Silicon application also sustained the membrane stability, supported via fewer electrolyte leakage processes and minor, O2- H2O2 and MDA levels during drought. Apart from this, the pepper plants significantly induced the expression level of the photosystem II-related genes, osmoprotectants pathway-associated genes, and antioxidant defense genes. Moreover, the GA biosynthesis genes were prompted, while the ABA signaling and biosynthesis genes were suppressed in the silicon-supplemented plants. These consequences infer that the role of Si supplementation on enhancing drought tolerance could be elucidated through the activation of secondary metabolites, flavonoid biosynthesis, osmoprotectants, GA pathway, the efficiency of PSII, and the suppression of chlorophyll degradation. Our research outcomes unveil new and remarkable characteristics of silicon supplementation and offer a series of candidate targets for improving the tolerance of pepper plants to drought stress.
摘要：
全球气候造成的干旱胁迫极大地干扰了植物的产量和生长。这里,我们探索了硅在抑制辣椒干旱机制中的假定作用以及次生代谢产物的显著参与,GA途径,和光系统II。我们的研究表明，类黄酮生物合成相关基因的转录水平，包括PAL,4-CL,CHS,FLS-1、F3H和DFR,在干旱胁迫期间，用硅处理的辣椒叶片逐渐诱导。此外，酚类和类黄酮化合物在辣椒植物中广泛诱导。此外，辣椒植物显著抑制叶绿素分解代谢相关基因，衰老相关标记基因，还有Rbohs基因.硅的应用也维持了膜的稳定性，通过较少的电解液泄漏过程和较小的过程来支持，干旱期间O2-H2O2和MDA水平。除此之外,辣椒植株显著诱导了光系统II相关基因的表达水平，渗透保护剂途径相关基因，和抗氧化防御基因.此外，GA生物合成基因被提示，而ABA信号和生物合成基因在硅补充植物中被抑制。这些结果推断，Si补充对提高耐旱性的作用可以通过激活次生代谢产物来阐明，类黄酮生物合成，渗透保护剂，GA途径,PSII的效率，和抑制叶绿素降解。我们的研究结果揭示了硅补充的新的和显着的特征，并提供了一系列候选目标，以提高辣椒植物对干旱胁迫的耐受性。
