Sah Saroj Kumar, Reddy Kambham Raja, Li Jiaxu
Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA.
Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS 39762, USA.
Plants (Basel). 2022 Jun 25;11(13):1687. doi: 10.3390/plants11131687.
Silicon has been implicated as a factor affecting the degree of resistance to abiotic stresses in several plant species. However, the role of silicon in soybean () under water-limiting conditions is not yet fully understood. This study was conducted to evaluate the effects of silicon application on the vegetative growth of two soybean cultivars (Asgrow 5332 and Progeny 5333) grown under water-limiting conditions. Silicon was provided by adding silicate to the soil. Water-limiting treatments were imposed on plants at two vegetative growth stages for 20 days by irrigating with a reduced amount of water (66% or 33% of the required water). Silicate application enhanced plant height, leaf area, and total dry weight of soybean plants. Significant increases in root volumes were observed in both the silicate-treated cultivars compared to the control plants under water-limiting conditions (33% irrigation). Net photosynthesis and stomatal conductance were decreased, but the quantum efficiency of photosystem II (Fv'/Fm') did not change under the same irrigation condition, which indicates photosynthesis downregulation through stomatal limitation. Silicate-treated plants in both cultivars had higher water use efficiency as compared to control plants under water-limiting conditions (irrigated with 66% or 33% of required water). Under water-limiting conditions, the soil moisture content was significantly higher in pots containing silicate than in those without added silicate, suggesting that silicon application improves water holding capacity. Taken together, the results from this study indicate that silicon application can improve the vegetative growth of soybeans under low water conditions by increasing the water use efficiency of plants and enhancing the soil's ability to retain moisture.
硅已被认为是影响几种植物对非生物胁迫抗性程度的一个因素。然而，在水分受限条件下硅在大豆（）中的作用尚未完全明确。本研究旨在评估施硅对两个大豆品种（Asgrow 5332和Progeny 5333）在水分受限条件下营养生长的影响。通过向土壤中添加硅酸盐来提供硅。在两个营养生长阶段对植株进行水分限制处理20天，方法是减少灌水量（所需水量的66%或33%）。施用硅酸盐提高了大豆植株的株高、叶面积和总干重。在水分受限条件下（33%灌溉量），与对照植株相比，两个施用硅酸盐处理的品种根系体积均显著增加。在相同灌溉条件下，净光合速率和气孔导度降低，但光系统II的量子效率（Fv'/Fm'）未发生变化，这表明光合作用通过气孔限制下调。在水分受限条件下（按所需水量的66%或33%灌溉），两个品种中施用硅酸盐处理的植株比对照植株具有更高的水分利用效率。在水分受限条件下，添加硅酸盐的花盆中土壤水分含量显著高于未添加硅酸盐的花盆，这表明施硅提高了持水能力。综上所述，本研究结果表明，施硅可以通过提高植物水分利用效率和增强土壤保水能力来改善低水分条件下大豆的营养生长。
