College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, PR China.
College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, PR China.
Plant Physiol Biochem. 2024 Feb;207:108416. doi: 10.1016/j.plaphy.2024.108416. Epub 2024 Feb 8.
Silicon (Si) and selenium (Se) can improve the tolerance of plants to NaCl-induced salt stress. However, few studies are available on their regulatory effects on plants' tolerance to calcium nitrate stress, which often occurs in protected facilities, causing secondary soil salinization. In this study, we report the effects of Si (6 mM) and Se (20 μM) applied separately or in combination on the growth, photosynthesis, oxidative damage, and nitrogen metabolism of tomato plants, as well as fruit quality under calcium nitrate stress. The results showed that applications of Si or Se alone or in combination improved the plant growth and photosynthetic performance and reduced oxidative damage of the stressed plants. Applications of Si and Se did not decrease the calcium accumulation in leaves of the stressed plants. Under calcium nitrate stress, the concentrations of NO, NO and NH in leaves were significantly increased, while the activities of nitrogen assimilation-related enzymes (including nitrate reductase, nitrite reductase, glutamine synthase, glutamine-2-oxoglutarate aminotransferase and glutamate dehydrogenase) were decreased. Applications of Si and Se, especially their combined treatment, decreased the NO, NO, and NH concentrations and enhanced the activities of nitrogen assimilation-related enzymes in the stressed plants. Applied Si and Se also decreased the nitrate and titratable acid concentrations and increased vitamin levels in tomato fruits under calcium nitrate stress. It is suggested that Si and Se improved the tomato plant growth and fruit quality under calcium nitrate stress by alleviating oxidative damage and promoting both photosynthesis and nitrogen assimilation.
硅（Si）和硒（Se）可以提高植物对 NaCl 诱导的盐胁迫的耐受性。然而，关于它们对植物耐硝酸盐胁迫的调节作用的研究很少，而硝酸盐胁迫在保护设施中经常发生，会导致次生土壤盐渍化。在这项研究中，我们报告了分别或联合施用硅（6 mM）和硒（20 μM）对番茄植株在硝酸盐胁迫下的生长、光合作用、氧化损伤和氮代谢以及果实品质的影响。结果表明，单独或联合施用硅或硒均能改善受胁迫植物的生长和光合作用性能，降低氧化损伤。硅和硒的施用并没有降低受胁迫植物叶片中的钙积累。在硝酸盐胁迫下，叶片中 NO、NO 和 NH 的浓度显著增加，而与氮同化相关的酶（包括硝酸还原酶、亚硝酸还原酶、谷氨酰胺合成酶、谷氨酰胺-2-酮戊二酸氨基转移酶和谷氨酸脱氢酶）的活性降低。硅和硒的施用，特别是它们的联合处理，降低了受胁迫植物中 NO、NO 和 NH 的浓度，增强了与氮同化相关的酶的活性。施用硅和硒还降低了硝酸盐和可滴定酸的浓度，并增加了番茄果实中维生素的含量，从而提高了番茄果实的品质。因此，硅和硒通过缓解氧化损伤和促进光合作用和氮同化，改善了番茄植株在硝酸盐胁迫下的生长和果实品质。
