Li Leilei, Qi Qian, Zhang Hengheng, Dong Qiang, Iqbal Asif, Gui Huiping, Kayoumu Mirezhatijiang, Song Meizhen, Zhang Xiling, Wang Xiangru
State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang 455000, China.
Western Agricultural Research Center of Chinese Academy of Agricultural Sciences, Changji 831100, China.
Antioxidants (Basel). 2022 Aug 4;11(8):1520. doi: 10.3390/antiox11081520.
Silicon (Si) could alleviate the adverse effect of salinity in many crops, but the effect in cotton remains unclear. In this study, we evaluated the role of Si in regulating the salt stress tolerance of cotton by analyzing the induced morpho-physiological changes. A hydroponic experiment was conducted by using contrasting salt-tolerant cotton genotypes (sensitive Z0102; tolerant Z9807) and four treatments (CK, control; CKSi, 0.4 mM Si; NaCl, 150 mM NaCl; NaClSi, 150 mM NaCl+0.4 mM Si). The results showed that Si significantly enhanced the net photosynthesis rate and improved the growth of cotton seedling under salt stress in both salt-sensitive and salt-tolerant genotypes. Exogenous Si significantly reduced the accumulation of reactive oxygen species (ROS) and decreased the malondialdehyde (MDA) content in salt-stressed cotton. In addition, the application of Si up-regulated the expression of , and , and significantly enhanced the antioxidant enzymatic activities, such as catalase (CAT) and peroxidase (POD), of the salt-stressed cotton seedlings. Further, Si addition protected the integrity of the chloroplast ultrastructure, including key enzymes in photosynthesis such as ferredoxin-NADP reeducates (FNR), ATP synthase (MgCa-ATPase) and ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO), and the structure and function of the photosynthetic apparatus PSII from salt stress. Moreover, Si significantly increased the effective stomatal density and stomatal aperture in the salt-stressed cotton seedlings. Taken together, Si could likely ameliorate adverse effects of salt stress on cotton by improving the ROS scavenging ability and photosynthetic capacity.
硅（Si）可以减轻盐分对许多作物的不利影响，但对棉花的影响尚不清楚。在本研究中，我们通过分析诱导的形态生理变化来评估硅在调节棉花耐盐性中的作用。采用耐盐性不同的棉花基因型（敏感型Z0102；耐盐型Z9807）和四种处理（CK，对照；CKSi，0.4 mM硅；NaCl，150 mM氯化钠；NaClSi，150 mM氯化钠 + 0.4 mM硅）进行水培试验。结果表明，在盐敏感型和耐盐型基因型中，硅均能显著提高盐胁迫下棉花幼苗的净光合速率并促进其生长。外源硅显著降低了盐胁迫棉花中活性氧（ROS）的积累，并降低了丙二醛（MDA）含量。此外，硅的施用上调了盐胁迫棉花幼苗中 、 和 的表达，并显著增强了过氧化氢酶（CAT）和过氧化物酶（POD）等抗氧化酶活性。此外，添加硅保护了叶绿体超微结构的完整性，包括光合作用中的关键酶，如铁氧还蛋白 - 烟酰胺腺嘌呤二核苷酸磷酸还原酶（FNR）、ATP合酶（MgCa - ATPase）和核酮糖 - 1,5 - 二磷酸羧化酶/加氧酶（RubisCO），以及光合机构PSII的结构和功能免受盐胁迫。此外，硅显著增加了盐胁迫棉花幼苗的有效气孔密度和气孔孔径。综上所述，硅可能通过提高活性氧清除能力和光合能力来减轻盐胁迫对棉花的不利影响。
