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）

Molecular cloning and characterization of a serine palmitoyltransferase gene from rice(Oryza sativa) and its gene expression in defense response to brown planthopper

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Os LCB2a1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。Os LCB2a1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。

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 c DNAs 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 Os LCB2 a1 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 m RNA level of Os LCB2 a1 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.