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.

Since the 1950s, with the introduction and application of winter rapeseed (Brassica napus) in China, it has led to the rapid transformation, i.e., replacing winter turnip rape by winter oil rape, in the Yangtze River Basin being the main production areas of winter rapeseed in China. In the late 1980s, with the continuous breakthroughs in cold tolerance breeding, the planting area of winter oil rapeseed continued to extend northward. Winter oil rapeseed had replaced winter turnip rapeseed in the main production areas in China, such as the HuangHuai River Basin, Weihe River Basin, and Weibei Dry Plateau. In recent years, strong cold resistant cabbage type winter oil glycerol 4 and other varieties have been developed, which can replace winter turnip rapeseed in arid and cold regions of northern China, achieving doubled yield of winter rapeseed, “double low” quality, and suitable machine harvesting for lodging resistance. The essence of the successful northward migration of winter rapeseed was the northward migration of winter oil rapeseed in China, namely cold resistant varieties of winter oil rapeseed replaced winter turnip rapeseed in the original production area, which have greatly promoted the development of winter rapeseed industry. Nevertheless, the northward migration of winter turnip rapeseed faces completely different difficulties. Since 1955, the northward migration trial of winter turnip rapeseed has been terminated by the introduction of spring oil rapeseed into the planting regions of spring turnip rapeseed at the same time. In the subsequent trial, there is a deviation in the research direction on techlonogies of the northward migration, i.e., solely paying close attention to the cold resistance, while ignoring drought tolerace of varieties which have been migrated into the northward migration area with further reduction in precipitation. There was resulting in technology output not meeting the actual needs of the industry. As a result, the northward migration practice has been carried out for decades and has not yet formed a stable winter rapeseed planting area outside of traditional production areas. In recent years, the original planting area has also continued to shrink, and the northward migration of winter turnip rapeseed has had little effect. In practical condition, the main challenge faced by the northward migration of winter turnip rapeseed is water limitation and the combination of drought and cold stress. The low comparative efficiency is the leading factor in the predicament of industrial development. In recent years, the strong cold-tolerant varieties of winter oil rapeseed developed can stably overwinter in northern cold and arid regions, replacing the varieties of winter turnip rapeseed, significantly improving yield, quality, planting efficiency of winter rapeseed, etc., which is the hope for winter rapeseed in strong winter regions to break through industrial difficulties. We have reviewed the history of winter rape northward-extension in China, achievements and existing problems. The reasons for the dilemma of northward extension were analyzes, and suggestions were made. The revolution of replacing winter turnip rape with winter oilseed rape should be promoted to meet the challenges in winter rape industry development in north China.