Zhang Jianqin, Zheng Dianfeng, Feng Naijie, Khan Aaqil, Deng Rui, Xiong Jian, Ding Linchong, Sun Zhiyuan, Li Jiahuan, Yang Xiaohui, Wu Chen
College of Coastal Agriculture Sciences, Guangdong Ocean University, Zhanjiang 524088, China.
South China Center of National Saline-Tolerant Rice Technology Innovation Center, Zhanjiang 524088, China.
Antioxidants (Basel). 2024 Dec 27;14(1):22. doi: 10.3390/antiox14010022.
Salt stress inhibits rice seed germination. Strigolactone (GR24) plays a vital role in enhancing plant tolerance against salt stress. However, GR24's impact on the metabolism of stored substances and endogenous hormones remains unclear. This study investigated the impact of exogenous GR24 on the metabolism of stored substances and endogenous hormones during the early stages of rice seed germination under salt stress. The results showed that salt stress significantly reduced the germination rate, germination potential, germination index, radicle length, germ length, and fresh and dry weights of the radicle and germ under salt stress. Pre-treatment (1.2 μmol L GR24) significantly reduced the inhibition of salt stress on rice seed germination and seedling growth. GR24 promoted the decomposition of starch by enhancing the activities of α-amylase, β-amylase, and total amylase and improved the levels of soluble sugars and proteins and the conversion rate of substances under salt stress. GR24 effectively enhanced the activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX); increased ascorbic acid (ASA) and glutathione (GSH) levels; and reduced malondialdehyde (MDA) content. This reduced the oxidative damage of salt stress. Furthermore, GR24 significantly increased the contents of strigolactones (SLs), auxin (IAA), gibberellin (GA3), cytokinin (CTK) as well as IAA/ABA, CTK/ABA, GA/ABA, and SL/ABA ratios and reduced abscisic acid (ABA) levels. The current findings indicate that GR24 effectively mitigates the adverse impact salt stress by regulating antioxidant enzyme activity and endogenous hormone balance.
盐胁迫抑制水稻种子萌发。独脚金内酯（GR24）在增强植物对盐胁迫的耐受性方面起着至关重要的作用。然而，GR24对贮藏物质和内源激素代谢的影响尚不清楚。本研究调查了外源GR24对盐胁迫下水稻种子萌发早期贮藏物质和内源激素代谢的影响。结果表明，盐胁迫显著降低了盐胁迫下的发芽率、发芽势、发芽指数、胚根长度、胚芽长度以及胚根和胚芽的鲜重和干重。预处理（1.2 μmol L GR24）显著降低了盐胁迫对水稻种子萌发和幼苗生长的抑制作用。GR24通过增强α-淀粉酶、β-淀粉酶和总淀粉酶的活性促进淀粉分解，并提高了盐胁迫下可溶性糖和蛋白质的水平以及物质转化率。GR24有效增强了超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的活性；提高了抗坏血酸（ASA）和谷胱甘肽（GSH）水平；降低了丙二醛（MDA）含量。这减少了盐胁迫的氧化损伤。此外，GR24显著增加了独脚金内酯（SLs）、生长素（IAA）、赤霉素（GA3）、细胞分裂素（CTK）的含量以及IAA/ABA、CTK/ABA、GA/ABA和SL/ABA的比值，并降低了脱落酸（ABA）水平。目前的研究结果表明，GR24通过调节抗氧化酶活性和内源激素平衡有效减轻了盐胁迫的不利影响。
