Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Genes (Basel). 2022 Nov 10;13(11):2084. doi: 10.3390/genes13112084.
Chinese cabbage, which is a cold season crop, can still be damaged at an overly low temperature. It is crucial to study the mechanism of the resistance to low temperature of Chinese cabbage. In this study, the Chinese cabbage 'XBJ' was used as the material, and nine different low temperatures and control samples were treated. Using RNA-seq and lignin content determination, we analyzed 27 samples, and the stained sections of them were observed. A total of 8845 genes were screened for the WGCNA analysis, yielding 17 modules. The GO and KEGG analyses of the modules was highly associated with a low-temperature treatment. The pathways such as 'starch and sucrose metabolism' and 'plant hormone signal transduction' were enriched in modules related to low temperature. Interestingly, L-15DAT-associated MEcoral2 was found to have 14 genes related to the 'lignin biosynthetic process' in the GO annotation. The combination of the determination of the lignin content and the treatment of the stained sections showed that the lignin content of the low-temperatures samples were indeed higher than that of the control. We further explored the expression changes of the lignin synthesis pathway and various genes and found that low temperature affects the expression changes of most genes in the lignin synthesis pathway, leading to the speculation that the lignin changes at low temperature are a defense mechanism against low temperatures. The 29 gene sequence derived from the RNA-seq was non-conserved, and eight genes were differentially expressed. This study provides a new insight into how lignin is affected by low temperature.
大白菜是一种冷季作物，即使在过低的温度下仍然可能受到损害。因此，研究大白菜的抗低温机制至关重要。本研究以大白菜品种‘XBJ’为材料，设置 9 个不同低温处理和对照，采用 RNA-seq 和木质素含量测定的方法，分析了 27 个样本，观察了它们的染色切片。通过 WGCNA 分析筛选出了 8845 个基因，共得到 17 个模块。这些模块的 GO 和 KEGG 分析与低温处理高度相关。与低温相关的模块中富集了“淀粉和蔗糖代谢”和“植物激素信号转导”等途径。有趣的是，在 GO 注释中发现与 L-15DAT 相关的 MEcoral2 有 14 个基因与“木质素生物合成过程”有关。木质素含量的测定和染色切片的处理结果表明，低温处理样品的木质素含量确实高于对照。我们进一步研究了木质素合成途径和各种基因的表达变化，发现低温影响木质素合成途径中大多数基因的表达变化，这使得我们推测低温下的木质素变化是一种低温防御机制。从 RNA-seq 中获得的 29 个基因序列没有保守性，其中 8 个基因差异表达。本研究为木质素如何受低温影响提供了新的见解。
