Department of Botany, Faculty of Science, Ain Shams University, Cairo, 11566, Egypt.
BMC Plant Biol. 2023 Oct 30;23(1):525. doi: 10.1186/s12870-023-04552-w.
The salinity threat represents an environmental challenge that drastically affects plant growth and yield. Besides salinity stress, the escalating world population will greatly influence the world's food security in the future. Therefore, searching for effective strategies to improve crop salinity resilience and sustain agricultural productivity under high salinity is a must. Seed priming is a reliable, simple, low-risk, and low-cost technique. Therefore, this work aimed to evaluate the impact of seed priming with 0.5 mM NaHS, as a donor of HS, in mitigating salinity effects on sunflower seedlings. Primed and nonprime seeds were established in nonsaline soil irrigated with tape water for 14 d, and then exposed to 150 mM NaCl for 7 d.
Salinity stress significantly reduced the seedling growth, biomass accumulation, K, Ca, and salinity tolerance index while elevating Na uptake and translocation. Salinity-induced adverse effects were significantly alleviated by HS priming. Upregulation in gene expression (HaSOS2, HaGST) under NaCl stress was further enhanced by HS priming. Also, HS reduced lipid peroxidation, electrolyte leakage, and HO content, but elevated the antioxidant defense system. NaCl-induced levels of ascorbate, glutathione, and α tocopherol, as well as the activities of AsA-GSH cycle enzymes: ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase, and glutathione S-transferase, were further enhanced by HS priming. Increased level of HS and total thiol by NaCl was also further stimulated by HS priming.
HS priming has proved to be an efficient strategy to improve sunflower seedlings' salinity tolerance by retaining ion homeostasis, detoxifying oxidative damage, modulating gene expression involved in ion homeostasis and ROS scavenging, and boosting endogenous HS. These findings suggested that HS acts as a regulatory molecule activating the functional processes responsible for sunflower adaptive mechanisms and could be adopted as a crucial crop management strategy to combat saline conditions. However, it would be of great interest to conduct further studies in the natural saline field to broaden our understanding of crop adaptive mechanisms and to support our claims.
盐胁迫是一种严重影响植物生长和产量的环境挑战。除了盐胁迫外，不断增长的世界人口将极大地影响未来世界的粮食安全。因此，寻找提高作物耐盐性和在高盐条件下维持农业生产力的有效策略是当务之急。种子引发是一种可靠、简单、低风险和低成本的技术。因此，本工作旨在评估用 0.5 mM NaHS 作为 HS 的供体对向日葵幼苗缓解盐胁迫的影响。将引发和未引发的种子种植在非盐渍土壤中，用自来水灌溉 14 天，然后暴露在 150 mM NaCl 中 7 天。
盐胁迫显著降低了幼苗的生长、生物量积累、K、Ca 和耐盐指数，同时增加了 Na 的吸收和转运。HS 引发显著减轻了盐胁迫的不利影响。在 NaCl 胁迫下，基因表达（HaSOS2、HaGST）进一步上调，HS 引发进一步增强。此外，HS 降低了脂质过氧化、电解质渗漏和 HO 含量，同时提高了抗氧化防御系统。HS 进一步增强了 NaCl 诱导的抗坏血酸、谷胱甘肽和α生育酚的水平，以及 AsA-GSH 循环酶的活性：抗坏血酸过氧化物酶、单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶、谷胱甘肽还原酶和谷胱甘肽 S-转移酶。HS 引发进一步刺激了 NaCl 诱导的 HS 和总巯基的增加。
HS 引发被证明是一种提高向日葵幼苗耐盐性的有效策略，通过保持离子稳态、解毒氧化损伤、调节参与离子稳态和 ROS 清除的基因表达、以及增强内源性 HS。这些发现表明，HS 作为一种调节分子，激活了负责向日葵适应机制的功能过程，可作为一种重要的作物管理策略，以应对盐渍条件。然而，在自然盐渍地进行进一步研究将极大地拓宽我们对作物适应机制的理解，并支持我们的观点。
