Li Wenxing, Li Yongping, Xu Yuan, Kumar Sunjeet, Liu Yi, Zhu Guopeng
Sanya Nanfan Research Institute, Hainan University, Sanya, 572025, China.
Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China.
BMC Plant Biol. 2024 Dec 6;24(1):1171. doi: 10.1186/s12870-024-05887-8.
The 12-oxo-phytodienoic acid reductase (OPR) enzyme is crucial for the synthesis of jasmonates (JAs), and is involved in the plant stress response. However, the OPR gene family in sweetpotato, an important horticultural crop, remains unidentified.
In this study, we employed bioinformatics techniques to identify nine IbOPR genes. Phylogenetic analysis revealed that these genes could be divided into Group I and Group II. Synteny analysis indicated that IbOPR evolution was driven by tandem duplication, whole-genome duplication (WGD), and segmental duplication events. The promoter sequences of IbOPRs were found to be associated with stress and hormonal responses. Additionally, we successfully cloned four IbOPRs from "Haida HD7791" and "Haida HD7798" using homologous cloning technology. These sequences were 1203 bp, 1200 bp, 1134 bp, and 1137 bp in length and encoded 400, 399, 377, and 378 amino acids, respectively. The protein sequence similarity between the salt-tolerant variety "Haida HD7791" and the salt-sensitive variety "Haida HD7798" was determined to be 96.75% for IbOPR2, 99.75% for IbOPR3, 92.06% for IbOPR6, and 98.68% for IbOPR7. Phylogenetic analysis categorized IbOPR2 and IbOPR3 proteins into Group II, while IbOPR6 and IbOPR7 proteins belonged to Group I. Subcellular localization experiments showed IbOPR2 protein present in the peroxisome, while IbOPR3, IbOPR6, and IbOPR7 proteins were found in the cytoplasm and nucleus. Salt stress induction experiments demonstrated that IbOPR2, IbOPR3, and IbOPR7 were significantly upregulated only in 'Haida HD7791' after 6 h. In contrast, IbOPR6 was induced in 'Haida HD7798' at 6 h but inhibited in 'Haida HD7791' at later time points (12, 24, 48, and 72 h), highlighting functional differences in salt stress responses.
Our findings suggest that IbOPR2 may play a crucial role in sweetpotato's response to salt stress by participating in JAs synthesis. These results provide a foundation for future functional analyses of OPR genes in sweetpotato.
12-氧代植物二烯酸还原酶（OPR）对于茉莉酸（JAs）的合成至关重要，并参与植物应激反应。然而，重要园艺作物甘薯中的OPR基因家族仍未被鉴定。
在本研究中，我们采用生物信息学技术鉴定出9个甘薯IbOPR基因。系统发育分析表明，这些基因可分为第I组和第II组。共线性分析表明，IbOPR的进化是由串联重复、全基因组复制（WGD）和片段重复事件驱动的。发现IbOPR的启动子序列与应激和激素反应相关。此外，我们利用同源克隆技术从“海大HD7791”和“海大HD7798”中成功克隆出四个IbOPR。这些序列长度分别为1203bp、1200bp、1134bp和1137bp，分别编码400、399、377和378个氨基酸。耐盐品种“海大HD7791”和盐敏感品种“海大HD7798”之间的IbOPR2蛋白序列相似性为96.75%，IbOPR3为99.75%，IbOPR6为92.06%，IbOPR7为98.68%。系统发育分析将IbOPR2和IbOPR3蛋白归类为第II组，而IbOPR6和IbOPR7蛋白属于第I组。亚细胞定位实验表明，IbOPR2蛋白存在于过氧化物酶体中，而IbOPR3、IbOPR6和IbOPR7蛋白存在于细胞质和细胞核中。盐胁迫诱导实验表明，6小时后，只有“海大HD7791”中的IbOPR2、IbOPR3和IbOPR7显著上调。相比之下，IbOPR6在“海大HD7798”中6小时被诱导，但在“海大HD7791”后期（12、24、48和72小时）受到抑制，突出了盐胁迫反应中的功能差异。
我们的研究结果表明，IbOPR2可能通过参与JAs合成在甘薯对盐胁迫的反应中发挥关键作用。这些结果为未来甘薯OPR基因的功能分析奠定了基础。
