水稻丝氨酸棕榈酰转移酶的分子克隆、特征及其与褐飞虱抗性相关的基因表达(英文)

为研究鞘脂质和鞘脂质代谢前体长链基团（long-chain bases, LCBs）对胁迫应答的调控机制，对编码水稻丝氨酸棕榈酰转移酶（serine palmitoyltransferase, SPT）的LCB基因进行克隆。通过反转录聚合酶链式反应（reverse transcription-polymerase chain reaction, RT-PCR）扩增到3 条LCB1和3条LCB2基因全长，蛋白质大小为481～497个氨基酸。生物信息学分析表明，LCB蛋白序列在细菌到人等多个物种中具有高度保守性。在褐飞虱（brown planthopper, BPH）的侵害作用下，水稻OsLCB2a1基因表达量上升。与其他水稻品种相比，抗性品种“Mudgo”和“IR64”中的基因表达量更高。基因表达量与褐飞虱危害指数呈负相关。在不同水稻品种的不同组织中，“IR64”叶片中的基因表达量显著升高，而“态平籼”叶鞘中的基因表达量显著升高。OsLCB2a1基因在抗褐飞虱水稻品种的最高分蘖期呈高表达，表明该基因可能在水稻营养期发挥作用。 通讯作者: ZHU Zengrong (https://orcid.org/0000-0002-3247-1486) E-mail: zrzhu@zju.edu.cn
Abstract: To understand potential mechanisms involved in sphingolipids and their metabolic precursors, longchain bases (LCBs)-mediated stress response, we cloned rice LCB genes that encode serine palmitoyltransferase (SPT), which is the key enzyme of sphingolipid de novo biosynthesis. The full-length cDNAs of three LCB1 and three LCB2 genes were amplified by reverse transcription-polymerase chain reaction (RT-PCR). The lengths of the deduced LCB proteins ranged from 481 to 497 amino acid residues. Bioinformatics and comparative studies revealed that the polypeptide proteins had high homology in a large number of species from bacteria to humans. In rice, we found that OsLCB2a1 expression was up-regulated when infested by brown planthopper (BPH). Compared with other varieties, gene expression levels were higher in BPH-resistant varieties such as Mudgo and IR64. Gene expression was negatively correlated with BPH-resistant scores. Among different plant parts of rice varieties, gene expression was found to be significantly increased in the leaf blade of IR64 and the leaf sheath of Taiping. The mRNA level of OsLCB2a1 was found to be high at the maximum tillering stage of BPH-resistant varieties, suggesting that this gene may play a role in the vegetative stages of rice. Key words: sphingolipid metabolism serine palmitoyltransferase defense gene expression pattern