关键词: 倒春寒, 农作物, 响应机制, 生理生化, 基因表达, 信号传导

Abstract:

In recent years, global climate change has continued to intensify, with extreme weather events occurring frequently, posing increasingly severe challenges to agricultural ecosystems. Late spring coldness, as a typical low-temperature meteorological disaster in spring, often occurs suddenly during the key growth stages of crops such as the germination period, flowering period or the growth of seedlings, causing damage to the plant cell membrane system and physiological metabolic disorders. In severe cases, it can lead to wilting or even death of plants, significantly affecting the stability of crop yields and the quality of agricultural products. It has become one of the important environmental stress factors restricting the sustainable development of agricultural production. Against this backdrop, delving deeply into the response mechanisms of plants to late spring coldness not only holds significant theoretical importance but also provides a solid theoretical foundation for the breeding of new crop varieties resistant to late spring coldness. This is of profound practical and strategic significance for enhancing the stress resistance of crops, stabilizing agricultural production levels, ensuring national food security, and promoting sustainable agricultural development. This article systematically reviews the multi-level response mechanisms of plants to the stress of late spring coldness. At the physiological and biochemical level, it includes the accumulation of osmotic adjustment substances (such as soluble sugars, proline, betaine, etc.), the activation of the antioxidant enzymes system (such as superoxide dismutase, peroxidase, catalase, etc.), and the adjustment of fatty acid saturation in membrane lipid composition (mainly manifested as an increase in the proportion of unsaturated fatty acids and a relative decrease in the proportion of saturated fatty acids). At the molecular level, the focus is on the perception and transmission pathways of low-temperature signals, covering the cascade regulatory network mediated by CBF/DREB-type transcription factors and the expression dynamics of downstream cold response genes, as well as a systematic analysis of the interactive regulatory roles of calcium ion signals and plant hormones (such as abscisic acid, jasmonic acid, cytokinin, brassinolide and ethylene) in response to low temperatures. In addition, this article also reviews the application progress of cutting-edge technologies such as high-throughput sequencing and CRISPR/Cas9 gene editing in the research of plant cold tolerance mechanisms, revealing the functional characteristics of multiple key cold tolerance genes and their regulatory networks. This article aims to construct a systematic theoretical framework of the molecular mechanism of plant resistance to late spring coldness through systematic integration and in-depth review of existing research results, providing solid scientific and technological support for the breeding of new crop varieties resistant to late spring coldness, the optimization of field management strategies, and the formulation of scientific and effective disaster prevention and mitigation measures.

Key words: late spring coldness, crops, response mechanism, physiology and biochemistry, gene expression, signal transduction