Physiological Mechanism of Exogenous Silicon Alleviating Drought Stress in Maize

Abstract

With the global warming, the impact of drought on agricultural production is increasingly prominent. Maize has a long growth period, high water demand, and is more sensitive to drought. Therefore, drought has always been one of the limited factors affecting the stable and increased on global maize production. Si promotes seed germination and seedling growth, enhances agricultural sustainability. However, its effects on different growth stages and different drought degree of maize are unclear in the field. In this experiment, to study its effects of drought in the large farmland moisture control test field (Xianyu 335) combined with exogenous Si during growth and development in maize. Exposed to drought-stressed conditions, Si further aggrandized antioxidant enzyme activities, reduced ROS contents, not only moderated AsA/DHA ratio but also GSH/GSSG ratio. Adding exogenous Si, the plant height growth rate, biomass, photosynthetic pigment contents, gas exchange parameters, photosynthetic enzymes activity, the stomatal size and aperture improved significantly, the contents of osmolyte further increased, as well as the increases were greater in the jointing stage than in the tasseling stage. In summary, applying exogenous Si can enhance the photosynthesis capacity of plants, promote the synthesis of osmotic substances, thus improving plant water metabolism balance, and enhance the antioxidant system, remove toxic substances, reduce membrane peroxidation, maintain cell membrane stability, alleviate stomatal limitation, and enhance maize drought resistance of the plant, thereby increasing yield.

Effect of silicon dioxide application and potassium levels on morphophysiological properties and storable seed yield of hybrid super sweet maize (Zea mays L. 'Elika') under drought stress

“…Under drought conditions, Si foliar application increased 1 000 seed weight (Table 4). The 182 increasing trend of 1000 seed weight as affected by Si application is due to the positive effects 183 of Si on assimilating transfer, photosynthetic enzymes activity, chlorophyll formation, and 184 plant growth improvement (Li et al 2022). In line with our findings, the positive effect of Si application on 1 000-seed weight has been reported maise (Zea mays L.) (Li et al 2022).…”