摘要
5羟色胺-N-乙酰转移酶(SNAT)是褪黑素合成过程中的关键酶之一。为揭示香蕉SNAT基因的功能,该研究对香蕉SNAT进行了全基因组鉴定,获得其中2个成员(MaSNAT1和MaSNAT2)并对它们进行克隆验证,结果发现仅MaSNAT2表达。对MaSNAT2进行了系列生物信息学分析,并通过实时荧光定量PCR技术研究其在MeJA、ABA、GA_(3)、褪黑素及低温处理下的表达模式。结果显示:(1)MaSNAT2基因CDS长度为741 bp,编码246个氨基酸;MaSNAT2蛋白定位于叶绿体,具有GNAT超家族典型保守Acetyltransf_7结构域;MaSNAT2二级结构主要由α螺旋、β折叠和无规则卷曲组成,三级结构与水稻OsSNAT相似度为81.60%。(2)MaSNAT2蛋白与小果野蕉SNAT相似度最高,亲缘关系最近;MaSNAT2启动子具有MeJA、ABA和GA_(3)等激素响应元件。(3)qRT-PCR结果显示,MaSNAT2基因的表达受ABA抑制;GA_(3)处理8 h和48 h后MaSNAT2表达量分别升高15.1倍和16.2倍;MeJA处理4 h后MaSNAT2表达量提高至5.2倍;褪黑素及低温处理能显著诱导MaSNAT2的表达。研究表明,MaSNAT2属于GNAT超家族,其表达受GA_(3)和MeJA诱导,受ABA抑制;该基因在香蕉响应低温胁迫过程中也发挥重要作用。
Serotonin-N-acetyltransferase(SNAT)is one of the key enzymes participating in melatonin synthesis.To reveal the function of banana SNAT gene,we performed genome-wide identification of banana SNAT genes and indentified two banana SNAT genes(MaSNAT1 and MaSNAT2).Gene cloning experiment showed that only MaSNAT2 was expressed,so only this gene was subjected to series of bioinformatic analysis.Moreover,its expression changes under MeJA,ABA,GA_(3),melatonin and low temperature treatments were investigated by using quantitative real time PCR(qRT-PCR).The results showed that:(1)the coding sequence(CDS)length of MaSNAT2 gene was 741 bp,which could encode a protein of 246 amino acids.MaSNAT2 was predicted to be chloroplast-located and owned the typical conserved domain(Acetyltransf_7)of the GNAT superfamily.The secondary structure of MaSNAT2 protein is mainly composed ofα-helix,βfolding and random coils,and its tertiary structure is highly similar to rice OsSNAT1(81.60%).(2)The MaSNAT2 protein shared the highest similarity with the SNAT protein of Musa acuminata subsp.malaccensis and their relationship was also the closest.Many phytohormone responsive elements such as MeJA-,ABA-and GA_(3)-responsive elements were identified in the MaSNAT2 promoter.(3)qRT-PCR results showed that the expression of MaSNAT2 could be suppressed by ABA treatment;the expression of MaSNAT2 increased by 15.1 and 16.2 times at 8 h and 48 h after GA_(3) treatment;the expression of MaSNAT2 increased by 5.2 times at 4 h after MeJA treatment;melatonin and low temperature treatment both increased the expression of MaSNAT2.MaSNAT2 belongs to the GNAT superfamily,its expression is GA_(3) and MeJA inducible,but it is greatly inhibited by ABA.Moreover,the gene might play important roles in the low temperature stress response of banana.
作者
刘嘉鹏
武欢
王斌
伍俊为
程春振
黄玉吉
LIU Jiapeng;WU Huan;WANG Bin;WU Junwei;CHENG Chunzhen;HUANG Yuji(College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou 350002,China;College of Horticulture,Shanxi Agricultural University,Taigu,Shanxi 030801,China)
出处
《西北植物学报》
CAS
CSCD
北大核心
2022年第4期569-577,共9页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31701900,31601713)
福建农林大学园艺学院优硕资助经费(102/1122YS01004)
福建农林大学科技创新专项基金(CXZX2020026A)。
