Analysis and Characterization of the GABA Transaminase and Succinate Semialdehyde Dehydrogenase Genes in the Microalga Isochrysis zhanjiangensis in Response to Abiotic Stresses  

作　　者：TIAN Jiaojiao ZHANG Lin LU Xinyue YE Lingzhi WU Yuanyuan CHEN Deshui CAO Jiayi JIANG Jiaxin XU Jilin YAN Xiaojun 

机构地区：[1]Key Laboratory of Marine Biotechnology of Zhejiang Province,School of Marine Sciences,Ningbo University,Ningbo 315211,China [2]Key Laboratory of Aquacultural Biotechnology Ministry of Education,Ningbo University,Ningbo 315211,China [3]Laizhou Bay Marine Technology Co.,Ltd.,Yantai 261400,China [4]Fujian Dalai Seed Science and Technology Co.,Ltd.,Ningde 352101,China

出　　处：《Journal of Ocean University of China》2024年第3期775-785,共11页中国海洋大学学报（英文版）

基　　金：supported by the Zhejiang Provincial Natural Science Foundation of China(No.LY22C190001);the Natural Science Foundation of Ningbo Government(No.2021J114);the Ningbo Science and Technology Research Projects,China(No.2019B10006);the Zhejiang Provincial Department of Education Scientific Research Project(No.Y202249030);the Earmarked Fund for CARS-49;partly sponsored by K.C.Wong Magna Fund in Ningbo University.

摘　　要：Gamma-aminobutyric acid(GABA),widely existing in different organisms,is rapidly accumulated in plants in response to environmental stresses.The main biosynthesis and degradation pathways of GABA constitute the GABA shunt,which is tied to the tricarboxylic acid(TCA)cycle.GABA transaminase(GABA-T)and succinate semialdehyde dehydrogenase(SSADH)are two essential enzymes for the GABA degradation pathway.While there are abundant studies on GABA shunt in higher plants at the physiological and genetic levels,research on its role in microalgae remains limited.This study aimed at exploring the function of GABA-T and SSADH genes in Isochrysis zhanjiangensis,an important diet microalga,under different stresses.We cloned two GABA-T genes,IzGABA-T1 and IzGABA-T2,and one SSADH gene IzSSADH from Isochrysis zhanjiangensis and conducted heterologous expression experiments.The results showed that the overexpression of IzGABA-T1 or IzGABA-T2 enhanced the survival rates of yeast transformants under heat or NaCl stress,while the overexpression of IzSSADH improved yeast tolerance to NaCl stress but had no obvious effect on heat stress.Additionally,the results of quantitative real-time polymerase chain reaction(qPCR)showed that IzGABA-T1 transcription increased in the HT(salinity 25,35℃)and LS(salinity 15,25℃)groups.At 24 h,the IzGABA-T2 transcriptions increased in the HT,LS,and HS(salinity 35,25℃)groups,but their transcription levels decreased in all groups at 48 h.IzSSADH transcription increased in the LS group.These results suggest that IzGABA-T1,IzGABA-T2,and IzSSADH are associated with temperature and salinity stresses and possess a certain preference for different stresses.

关 键 词：abiotic stress GABA heterologous expression Isochrysis zhanjiangensis TRANSCRIPTION 

分 类 号：S917.3[农业科学—水产科学]