College of Life Science, Baicheng Normal University, Baicheng, 137000, China.
College of Forestry and Grassland Science, Jilin Agricultural University, Jilin, 130118, China.
BMC Plant Biol. 2024 Oct 17;24(1):973. doi: 10.1186/s12870-024-05691-4.
Castor is an important industrial raw material. Drought-induced oxidative stress leads to slow growth and decreased yields in castor. However, the mechanisms of drought-induced oxidative stress in castor remain unclear. Therefore, in this study, physiological, biochemical, and RNA-seq analyses were conducted on the roots of castor plants under PEG-6000 stress for 3 d and 7 d followed by 4 d of hydration.
The photosynthetic rate of castor leaves was inhibited under PEG-6000 stress for 3 and 7 d. Biochemical analysis of castor roots stressed for 3 d and 7 d, and rehydrated for 4 d revealed that the activities of APX and CAT were highest after only 3 d of stress, whereas the activities of POD, GR, and SOD peaked after 7 d of stress. RNA-seq analysis revealed 2926, 1507, and 111 differentially expressed genes (DEGs) in the roots of castor plants under PEG-6000 stress for 3 d and 7 d and after 4 d of rehydration, respectively. GO analysis of the DEGs indicated significant enrichment in antioxidant activity. Furthermore, KEGG enrichment analysis of the DEGs revealed significantly enriched metabolic pathways, including glutathione metabolism, fatty acid metabolism, and plant hormone signal transduction. WGCNA identified the core genes PP2C39 and GA2ox4 in the navajowhite1 module, which was upregulated under PEG-6000 stress. On the basis of these results, we propose a model for the response to drought-induced oxidative stress in castor.
This study provides valuable antioxidant gene resources, deepening our understanding of antioxidant regulation and paving the way for further molecular breeding of castor plants.
蓖麻是一种重要的工业原料。干旱诱导的氧化应激导致蓖麻生长缓慢，产量降低。然而，蓖麻干旱诱导氧化应激的机制尚不清楚。因此，本研究对 PEG-6000 胁迫下的蓖麻根进行了 3 天和 7 天以及 4 天复水后的生理、生化和 RNA-seq 分析。
PEG-6000 胁迫下，蓖麻叶片的光合速率受到抑制。对胁迫 3 天和 7 天、复水 4 天的蓖麻根进行生化分析表明，APX 和 CAT 的活性在胁迫仅 3 天后最高，而 POD、GR 和 SOD 的活性在胁迫 7 天后最高。RNA-seq 分析显示，PEG-6000 胁迫 3 天和 7 天以及复水 4 天后，蓖麻根中有 2926、1507 和 111 个差异表达基因（DEGs）。DEGs 的 GO 分析表明，抗氧化活性显著富集。此外，DEGs 的 KEGG 富集分析显示，代谢途径明显富集，包括谷胱甘肽代谢、脂肪酸代谢和植物激素信号转导。WGCNA 在 navajowhite1 模块中鉴定出 PP2C39 和 GA2ox4 这两个核心基因，它们在 PEG-6000 胁迫下上调。基于这些结果，我们提出了蓖麻应对干旱诱导氧化应激的模型。
本研究提供了有价值的抗氧化基因资源，加深了我们对抗氧化调控的理解，为蓖麻植物的进一步分子育种铺平了道路。
