Usmani Muhammad Munir, Nawaz Fahim, Majeed Sadia, Shehzad Muhammad Asif, Ahmad Khawaja Shafique, Akhtar Gulzar, Aqib Muhammad, Shabbir Rana Nauman
Department of Agronomy, MNS University of Agriculture, Multan, Pakistan.
Department of Agronomy, University College of Agriculture and Environmental Sciences, Bahawalpur, Pakistan.
Sci Rep. 2020 Jan 24;10(1):1147. doi: 10.1038/s41598-020-58169-2.
Restriction in nutrient acquisition is one of the primary causes for reduced growth and yield in water deficient soils. Sulfur (S) is an important secondary macronutrient that interacts with several stress metabolites to improve performance of food crops under various environmental stresses including drought. Increased S supply influences uptake and distribution of essential nutrients to confer nutritional homeostasis in plants exposed to limited water conditions. The regulation of S metabolism in plants, resulting in synthesis of numerous S-containing compounds, is crucial to the acclimation response to drought stress. Two different experiments were laid out in semi-controlled conditions to investigate the effects of different S sources on physiological and biochemical mechanisms of maize (Zea mays L. cv. P1574). Initially, the rate of S application in maize was optimized in terms of improved biomass and nutrient uptake. The maize seedlings were grown in sandy loam soil fertigated with various doses (0, 15, 30 and 45 kg ha) of different S fertilizers viz. KSO, FeSO, CuSO and NaSO. The optimized S dose of each fertilizer was later tested in second experiment to determine its role in improving drought tolerance of maize plants. A marked effect of S fertilization was observed on biomass accumulation and nutrients uptake in maize. In addition, the optimized doses significantly increased the gas exchange characteristics and activity of antioxidant enzymes to improve yield of maize. Among various S sources, application of KSO resulted in maximum photosynthetic rate (43%), stomatal conductance (98%), transpiration rate (61%) and sub-stomatal conductance (127%) compared to no S supply. Moreover, it also increased catalase, guaiacol peroxidase and superoxide dismutase activities by 55, 87 and 65%, respectively that ultimately improved maize yield by 33% with respect to control under water deficit conditions. These results highlight the importance of S fertilizers that would likely be helpful for farmers to get better yield in water deficient soils.
养分获取受限是缺水土壤中作物生长和产量降低的主要原因之一。硫（S）是一种重要的次生大量元素，它与多种胁迫代谢产物相互作用，以提高包括干旱在内的各种环境胁迫下粮食作物的性能。增加硫供应会影响必需养分的吸收和分配，从而在水分条件有限的植物中实现营养平衡。植物中硫代谢的调节导致多种含硫化合物的合成，这对于干旱胁迫的适应反应至关重要。在半控制条件下进行了两个不同的实验，以研究不同硫源对玉米（Zea mays L. cv. P1574）生理和生化机制的影响。首先，根据生物量和养分吸收的改善情况对玉米中的硫施用量进行了优化。玉米幼苗种植在砂壤土中，用不同剂量（0、15、30和45 kg·ha）的不同硫肥即硫酸钾（K₂SO₄）、硫酸亚铁（FeSO₄）、硫酸铜（CuSO₄）和硫酸钠（Na₂SO₄）进行灌溉施肥。每种肥料的优化硫剂量随后在第二个实验中进行测试，以确定其在提高玉米植株耐旱性方面的作用。观察到硫肥对玉米生物量积累和养分吸收有显著影响。此外，优化剂量显著提高了气体交换特性和抗氧化酶活性，从而提高了玉米产量。在各种硫源中，与不供应硫相比，施用硫酸钾导致光合速率最高（43%）、气孔导度最高（98%）、蒸腾速率最高（61%）和胞间二氧化碳浓度最高（127%）。此外，它还分别使过氧化氢酶、愈创木酚过氧化物酶和超氧化物歧化酶活性提高了55%、87%和65%，最终在水分亏缺条件下相对于对照使玉米产量提高了33%。这些结果突出了硫肥的重要性，这可能有助于农民在缺水土壤中获得更高的产量。
