Zhang Zanpei, Mao Qianxing, Gu Yueying, Shang Xulan, Huang Yanmeng, Fang Shengzuo
College of Forestry and Grassland, Nanjing Forestry University, Nanjing, 210037, China.
Co-Innovation Center for the Sustainable Forestry in Southern China, Nanjing, 210037, China.
BMC Genomics. 2025 Jan 13;26(1):31. doi: 10.1186/s12864-025-11218-4.
Cold stress in winter is one of the most severe abiotic stresses on plant growth and flourishing, and the selection of cold tolerant genotypes is an important strategy to ensure the safety of plant growth and development. Cyclocarya paliurus, a diclinous and versatile tree species originally in subtropical regions, has been introduced and cultivated in the warm temperate zone of China to meet the increasing market demand for its leaf yield. However, information regarding its cold tolerance remains limited. Based on the ploidy identification of tested materials, an imitation experiment was conducted to investigate the variation in freezing injury index and expression of the CpaWRKY family members in diploid and tetraploid C. paliurus seedlings. The results indicated a significant difference in freezing injury index between diploids and tetraploids under the imitating temperature of southern warm temperate zone, with diploids showing better cold tolerance than the tetraploids. A total of 88 CpaWRKY genes were identified from the C. paliurus genome, and RNA-Seq results showed significant differences in WRKY gene expression in C. paliurus under cold stress. Correlation analysis between differentially expressed genes and freezing injury index suggested that CpaWRKY14, CpaWRKY26 and CpaWRKY86 play essential roles in the diploids to respond to cold stress. In contrast, the major genes involved in the cold stress response in tetraploids were CpaWRKY14, CpaWRKY60, CpaWRKY63 and CpaWRKY81. Moreover, CpaWRKY14 expression was considerably higher in diploids compared to tetraploids. The results from this study not only enhance our comprehension of the role of the CpaWRKY genes in cold stress, but also provide a foundation for the genetic improvement of C. paliurus.
冬季的低温胁迫是影响植物生长和繁茂的最严重非生物胁迫之一，选择耐寒基因型是确保植物生长发育安全的重要策略。青钱柳是一种原产于亚热带地区的雌雄异株且用途广泛的树种，为满足市场对其叶片产量日益增长的需求，已在中国暖温带地区引种栽培。然而，关于其耐寒性的信息仍然有限。基于对试验材料的倍性鉴定，进行了模拟试验，以研究二倍体和四倍体青钱柳幼苗冻害指数的变化以及CpaWRKY家族成员的表达情况。结果表明，在模拟南方暖温带地区的温度条件下，二倍体和四倍体的冻害指数存在显著差异，二倍体的耐寒性优于四倍体。从青钱柳基因组中总共鉴定出88个CpaWRKY基因，RNA测序结果表明，低温胁迫下青钱柳WRKY基因的表达存在显著差异。差异表达基因与冻害指数的相关性分析表明，CpaWRKY14、CpaWRKY26和CpaWRKY86在二倍体响应低温胁迫中起关键作用。相比之下，四倍体中参与低温胁迫响应的主要基因是CpaWRKY14、CpaWRKY60、CpaWRKY63和CpaWRKY81。此外，二倍体中CpaWRKY14的表达明显高于四倍体。本研究结果不仅加深了我们对CpaWRKY基因在低温胁迫中作用的理解，也为青钱柳的遗传改良提供了依据。
