Zhu Lin, Li Zhiyong, Zhang Xiaoqing, Yin Guomei, Liu Siqi, Zhao Jinmei, Yun Ying, Guo Maowei, Zhang Jiaqi
Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot 010011, China.
Key Laboratory of Forage Resources and Utilization, Ministry of Agriculture and Rural Affairs, Hohhot 010010, China.
Plants (Basel). 2025 Apr 26;14(9):1313. doi: 10.3390/plants14091313.
Alfalfa () is a globally distributed economic legume crop used for forage and ecological restoration. We aimed to explore the mechanisms underlying the cold acclimation observed in this species. Our results for fall plant growth showed that non-dormant alfalfa (SD) maintained a vigorous growth rate compared to that of fall-dormant alfalfa (ZD); however, the winter survival rate of ZD was higher than that of SD. Among the ZD samples, the starch content first accumulated and then decreased; the sucrose content was consumed first along with simultaneous raffinose accumulation, which was followed by sucrose content accumulation, with consistent changes in the corresponding related synthase and hydrolase activity. SD exhibited the opposite trend. The transcriptome data showed that most of the differentially expressed genes were involved in carbon metabolism (ko01200), amino acid biosynthesis (ko01230), and starch and sucrose metabolism (ko00500). Our data clearly show that alfalfa's cold acclimation mechanism is a complex process, with the establishment of stable carbon homeostasis; sucrose is first converted into starch and raffinose, and then, starch is converted into sucrose, which enables alfalfa's cold resistance. The process is accompanied by CBF/DREB1A TF regulation. This study provides important insights into the cold acclimation mechanisms of alfalfa.
紫花苜蓿（Medicago sativa）是一种全球分布的经济豆类作物，用于饲料和生态恢复。我们旨在探索该物种中观察到的冷驯化潜在机制。我们秋季植物生长的结果表明，与秋季休眠紫花苜蓿（ZD）相比，非休眠紫花苜蓿（SD）保持了旺盛的生长速率；然而，ZD的冬季存活率高于SD。在ZD样本中，淀粉含量先积累后下降；蔗糖含量首先被消耗，同时棉子糖积累，随后蔗糖含量积累，相应相关合成酶和水解酶活性发生一致变化。SD表现出相反的趋势。转录组数据表明，大多数差异表达基因参与碳代谢（ko01200）、氨基酸生物合成（ko01230）以及淀粉和蔗糖代谢（ko00500）。我们的数据清楚地表明，紫花苜蓿的冷驯化机制是一个复杂的过程，伴随着稳定碳稳态的建立；蔗糖首先转化为淀粉和棉子糖，然后淀粉转化为蔗糖，这使紫花苜蓿具有抗寒能力。该过程伴随着CBF/DREB1A转录因子调控。本研究为紫花苜蓿的冷驯化机制提供了重要见解。
