Agricultural Botany Department, Faculty of Agriculture, Mansoura University, 35516 Mansoura, Egypt.
Department of Plant Production, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia; Department of Vegetable and Floriculture, Faculty of Agriculture, Mansoura University, 35516 Mansoura, Egypt.
Ecotoxicol Environ Saf. 2020 Dec 15;206:111396. doi: 10.1016/j.ecoenv.2020.111396. Epub 2020 Oct 8.
Salinity is a key worldwide ecological restriction to sustainable crop production and food security. Various methods were used for inducing salinity tolerance including biotechnological approaches or application of stress tolerance-inducing substances. Silicon supplementation has a decisive role in alleviating of salinity injury, however, the definite mechanisms behind stay scantily understood, and must be examined. The imperative roles of sodium metasilicate (Si, 100 ppm) application methods (foliar spraying at 100 mg/l; soil additive at 100 mg/kg soil; foliar spraying at 100 mg/l plus soil additive at 100 mg/kg soil), in improving growth and essential oil yield, maintaining water status, activating antioxidant system, and keeping ion homeostasis of salt affected-sweet basil (6000 mg NaCl/kg soil) were studied. Salinity induced a notable increase in oxidative biomarkers, coupled with higher osmolyte concentration and osmotic potential (OP) values, as well as increased superoxide dismutase and peroxidase activities. Alternatively, sweet basil growth, essential oil yield, and catalase activity were reduced under salinity. Furthermore, salinity aggravated ion imbalance, decreased photosynthetic pigment and disrupted the plants' water status. Silicon application drastically increased osmolyte accumulation associated with sustained water status, increased OP, and improved osmotic adjustment (OA) capacity. Additionally, Si application enhanced antioxidant aptitude associated with decreased oxidative biomarkers and improved growth, photosynthetic pigment, and essential oil yield. Greater outcomes were achieved with the foliar spraying method, compared with other application methods. Salinity stress evoked modification in protein assimilation capacity and possibly will withdraw protein biosynthesis and reduce total protein band number; however, Si application may adjust the expression of salinity inducible proteins. Foliar spraying of Si with or without soil additive accelerates the expression of peroxidase isozyme over salinized or control plants. Collectively, Si foliar spraying alleviated salinity-related injuries on sweet basil by maintaining water status, increasing osmolyte assimilation, improving OA, enhancing redox homeostasis, and antioxidant capacity.
盐度是全球范围内限制可持续作物生产和粮食安全的关键生态因素。为了提高盐度耐受性，人们采用了各种方法，包括生物技术方法或应用胁迫耐受诱导物质。硅的补充在缓解盐害方面起着决定性的作用，然而，其背后的确切机制仍知之甚少，需要进一步研究。本研究探讨了硅酸钠（Si，100ppm）应用方法（100mg/L 叶面喷施；100mg/kg 土壤的土壤添加；100mg/L 叶面喷施加 100mg/kg 土壤的土壤添加）在改善生长和精油产量、维持水分状况、激活抗氧化系统和保持受盐影响的甜罗勒（6000mgNaCl/kg 土壤）离子内稳性方面的作用。盐胁迫显著增加了氧化生物标志物的含量，同时提高了渗透调节剂浓度和渗透势（OP）值，以及超氧化物歧化酶和过氧化物酶的活性。相反，盐胁迫会降低甜罗勒的生长、精油产量和过氧化氢酶活性。此外，盐胁迫加剧了离子失衡，降低了光合色素含量，破坏了植物的水分状况。硅的应用显著增加了与持续水分状况相关的渗透调节剂的积累，提高了 OP，并改善了渗透调节能力。此外，硅的应用增强了抗氧化能力，降低了氧化生物标志物，并改善了生长、光合色素和精油产量。与其他应用方法相比，叶面喷施法的效果更好。盐胁迫会改变蛋白质同化能力，可能会抑制蛋白质的生物合成并减少总蛋白质带数；然而，硅的应用可能会调节盐诱导蛋白的表达。叶面喷施硅或与土壤添加物一起喷施硅可加速过氧化物同工酶的表达，无论是在盐胁迫或对照植物中。总的来说，叶面喷施硅通过维持水分状况、增加渗透调节剂的吸收、改善渗透调节能力、增强氧化还原平衡和抗氧化能力，缓解了甜罗勒的盐害。
