杧果乙烯受体基因MiETR1b的分离与表达分析  

Isolation and Expression Analysis of an Ethylene Receptor Gene Mi ETR1b in Mango

作　　者：李运合[1,2] 张智[1] 吴青松[1,2] 

机构地区：[1]中国热带农业科学院南亚热带作物研究所,广东湛江524091 [2]农业部热带果树生物学重点实验室,广东湛江524091

出　　处：《园艺学报》2015年第6期1021-1030,共10页Acta Horticulturae Sinica

基　　金：国家自然科学基金项目(31372053)

摘　　要：以‘紫花杧’杧果(Mangifera indica L.‘Zihua’)子叶切段为材料,采用RT-PCR结合RACE方法得到乙烯受体基因ETR1的c DNA及基因组DNA全长,命名为Mi ETR1b。该基因c DNA全长2 530 bp,开放读码框为2 220 bp,编码739个氨基酸;其基因组DNA全长4 116 bp,其中从起始密码子到终止密码子为3 305 bp,含有6个外显子和5个内含子。氨基酸序列多重比对及系统发育树结果显示Mi ETR1b与Mi ETR1亲缘关系最近,与Cs ERS1、Dl ETR1、Tc ERS1、Ptr ETR1有较高的同源性,且具有保守的GAF域和组氨酸激酶域。这些结果表明,Mi ETR1b为ETR1家族同源基因。荧光定量PCR结果表明,Mi ETR1b在杧果子叶切段不定根形成过程中在远轴端和近轴端都有表达,其中远轴端0.25~2 d的表达量显著上调;吲哚丁酸(IBA)和2,3,5–三碘苯甲酸(TIBA)预处理后分别在1 d和6 h显著下调。另一方面,在培养的初期,即0.5~1 d,乙烯释放量相对较高,4 d及其以后的乙烯释放量急剧下降,表明杧果子叶切段不定根形成过程中有较多乙烯生成,提示Mi ETR1b可能参与了不定根的形成。A mango ETHYLENE RESPONSE1(ETR1)gene,designated as Mi ETR1 b,was isolated from the cotyledon of mango(Mangifera indica L.‘Zihua')using RT-PCR and RACE. The full-length c DNA was 2 530 bp with an open reading frame of 2 220 bp,encoding a putative protein of 739 amino acids. The genomic DNA sequence of Mi ETR1 b was 4 116 bp long with a sequence of 3 305 bp from start codon to terminator codon containing six exons and five introns. The deduced amino acids possessed conserved domains of GAF and HATPase_c superfamily. Phylogenetic tree analysis indicated that Mi ETR1 b had the highest similarity with Mi ETR1 from M. indica,and had high similarity with Cs ERS1,Dl ETR1,Tc ERS1 and Ptr ETR1. Quantitative real-time PCR showed that Mi ETR1 b expressed in proximal cut surface or distal cut surface throughout the adventitious root formation period. Meanwhile,the expression of Mi ETR1 b in distal cut surface was significantly up-regulated within 0.25–2 days. Howeve,pre-treatment with indole-3-butyric acid(IBA)and 2,3,5-triiodobenzoic acid(TIBA)significantly down-regulated Mi ETR1 b expression of 1 day and 6 hours,respectively. On the other hand,more ethylene produced within 0.5–1 day,while the ethylene production decreased after 4 days of culture. In conclusion,Mi ETR1 b might play an important role during the adventitious root formation of mango cotyledon segments,which was related to ethylene production.

关 键 词：杧果 MiETR1b 表达分析 不定根 

分 类 号：S667.7[农业科学—果树学]