College of Agriculture, Inner Mongolia Agricultural University, Hohhot, 010018, China.
BMC Plant Biol. 2024 Mar 27;24(1):224. doi: 10.1186/s12870-024-04932-w.
Drought severely limits sunflower production especially at the seedling stage. To investigate the response mechanism of sunflowers to drought stress, we utilized two genotypes of sunflower materials with different drought resistances as test materials. The physiological responses were investigated under well-watered (0 h) and drought-stressed conditions (24 h, 48 h, and 72 h).
ANOVA revealed the greatest differences in physiological indices between 72 h of drought stress and 0 h of drought stress. Transcriptome analysis was performed after 72 h of drought stress. At 0 h, there were 7482 and 5627 differentially expressed genes (DEGs) in the leaves of K55 and K58, respectively, and 2150 and 2527 DEGs in the roots of K55 and K58, respectively. A total of 870 transcription factors (TFs) were identified among theDEGs, among which the high-abundance TF families included AP2/ERF, MYB, bHLH,and WRKY. Five modules were screened using weighted gene coexpressionnetwork analysis (WGCNA), three and two of which were positively and negatively, respectively, related to physiological traits. KEGG analysis revealedthat under drought stress, "photosynthesis", "carotenoid biosynthesis", "starch and sucrose metabolism", "ribosome", "carotenoid biosynthesis", "starch and sucrose metabolism", "protein phosphorylation" and "phytohormone signaling" are six important metabolic pathways involved in the response of sunflower to drought stress. Cytoscape software was used to visualize the three key modules, and the hub genes were screened. Finally, a total of 99 important candidate genes that may be associated with the drought response in sunflower plants were obtained, and the homology of these genes was compared with that in Arabidopsis thaliana.
Taken together, our findings could lead to a better understanding of drought tolerance in sunflowers and facilitate the selection of drought-tolerant sunflower varieties.
干旱严重限制向日葵的生产，尤其是在幼苗期。为了研究向日葵对干旱胁迫的响应机制，我们利用两种抗旱性不同的向日葵材料作为试验材料。在充分供水（0 h）和干旱胁迫条件下（24 h、48 h 和 72 h），对生理反应进行了研究。
方差分析显示，干旱胁迫 72 h 与 0 h 之间的生理指标差异最大。在干旱胁迫 72 h 后进行转录组分析。在 0 h 时，K55 和 K58 的叶片分别有 7482 和 5627 个差异表达基因（DEGs），根部分别有 2150 和 2527 个 DEGs。在 DEGs 中鉴定出 870 个转录因子（TFs），其中高丰度 TF 家族包括 AP2/ERF、MYB、bHLH 和 WRKY。使用加权基因共表达网络分析（WGCNA）筛选出 5 个模块，其中 3 个模块为正相关，2 个模块为负相关，分别与生理性状相关。KEGG 分析表明，在干旱胁迫下，“光合作用”、“类胡萝卜素生物合成”、“淀粉和蔗糖代谢”、“核糖体”、“类胡萝卜素生物合成”、“淀粉和蔗糖代谢”、“蛋白质磷酸化”和“植物激素信号转导”是参与向日葵对干旱胁迫响应的六个重要代谢途径。使用 Cytoscape 软件可视化三个关键模块，并筛选出枢纽基因。最后，共获得 99 个可能与向日葵植物抗旱性相关的重要候选基因，并与拟南芥的同源性进行了比较。
综上所述，我们的研究结果可以更好地理解向日葵的耐旱性，并有助于选择耐旱的向日葵品种。
