Maize Genomics and Genetics 2025, Vol.16, No.3, 108-118 http://cropscipublisher.com/index.php/mgg 116 key genes involved in antioxidant defense, osmotic regulation, heat shock protein synthesis and energy metabolism. At the metabolome level, salicylic acid significantly promoted the accumulation of key stress relief metabolites such as proline, soluble sugar, glutathione and carotenoids, and enhanced the plant's self-protection ability against high temperature-induced cell damage. 7.2 Precision nutritional intervention In the comprehensive technical system for coping with high temperature stress, targeted nutritional intervention, as a fast, efficient and universally applicable strategy, is gradually becoming an important technical path for heat-resistant cultivation of corn. On the one hand, high temperature often leads to reduced root activity and decreased mineral nutrient absorption efficiency, especially the lack of key trace elements such as calcium, boron, zinc, and magnesium, which will further weaken the stability of corn cell membranes, photosynthetic efficiency, and normal development of reproductive organs. On the other hand, high temperature will also aggravate the accumulation of reactive oxygen species (ROS) and lipid peroxidation in the body, causing cell damage. In response to this problem, researchers promote targeted nutritional intervention measures to build a "nutritional heat-resistant barrier" by rationally supplementing physiologically active nutrients and antioxidants during key growth periods (such as jointing and tasseling). Biostimulants such as seaweed extracts, humic acids, and amino acid complexes can significantly improve plant antioxidant capacity, membrane stability, and heat-resistant enzyme expression. Trace elements such as zinc, boron, and calcium play an important role in cell signal regulation, heat stress relief, and pollen vitality maintenance. Studies have shown that foliar spraying of nutrients rich in heat-resistant ingredients can improve the heat resistance of plants during the tasseling and silking periods, and reduce the proportion of empty stalks and bald tips (Saini et al., 2021). In combination with modern agricultural technology, some areas have also begun to use chelated micro-fertilizers (such as EDTA-Ca, Zn-EDTA) and plant biostimulants (such as humic acid, alginic acid, amino acid compound liquid, etc.) for foliar spraying, which can not only directly improve the plant's stress resistance metabolism level, but also stimulate the activation of endogenous heat resistance pathways, forming a dual heat resistance mechanism of "nutrition + regulation". This nutritional intervention technology has shown significant advantages in the field. It can alleviate premature leaf senescence during high temperatures, improve pollination quality, prolong the filling period and maintain the photosynthetic efficiency of the group, effectively reduce yield losses in high temperature years, and is the "soft technology support" for the current prevention and control of corn heat damage. 7.3 Optimization of integrated cultivation strategies In the context of global climate change, relying solely on genetic improvement can no longer fully cope with the yield risks brought about by high temperature stress. At present, integrated cultivation technology has gradually become a key supplementary path to improve the heat resistance and stable yield of corn. In particular, the close planting precision control technology, as the core content of the integrated agronomic management system, has been widely used in high-density planting areas to synergistically improve the output per unit area and environmental adaptability. According to the latest research and practical experience, the close planting precision control technology is not only an effective way to release high-yield potential, but also plays an important role in corn's response to high temperature stress. The core of this technology is to systematically configure and dynamically adjust the planting density, row spacing, sowing period and field management measures based on variety characteristics, soil conditions and climate factors. By optimizing the planting pattern, not only can the photosynthetic efficiency of the group be improved, but also the competitive pressure and heat accumulation problems caused by the density can be effectively alleviated, thereby reducing the impact of heat damage on reproductive growth. Specific measures include: selecting high-density tolerant varieties to strengthen the stability of the population structure; implementing precision sowing technology to ensure uniform density through mechanized strip sowing and GPS positioning technology; regulating the population structure and canopy ventilation to improve field permeability and reduce ear temperature; combining water-fertilizer integration and micro-spray irrigation
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