摘要
MEE70/MSI1是拟南芥母性效应胚胎滞育基因,在植物胚胎发生过程中具有重要作用。采用RACE技术获得龙眼MEE70-1a(登录号KC492117)及其可变剪接体MEE70-1b(登录号KC492118)c DNA序列,克隆MSI1g DNA(登录号KC492126)序列。生物信息学分析预测Dl MEE70-1a和Dl MEE70-1b均为亲水不稳定的酸性蛋白,主要定位于过氧化物酶体和细胞核,各含有4和1个WD-repeat结构域。MEE70-1a和MEE70-1b在体细胞胚胎发生过程实时荧光定量PCR分析结果表明,Dl MEE70-1a和Dl MEE70-1b表达趋势以心形胚为界,除了Dl MEE70-1b的不完全胚型紧实结构(ICp EC)到球形胚(GE)阶段之间,都表现出先降后升的趋势;胚性愈伤组织(EC)时期两者表达量一致且最高;心形胚(HE)时期,两者表达量一致且最低,另Dl MEE70-1b在不完全胚性紧实结构(ICp EC)表达量与心形胚基本一致。这2个表达剂量是胚胎发生的重要保障,心形胚(HE)后,Dl MEE70-1a被再次激活转录促进胚胎正常发育。从Dl MEE70-1a和Dl MEE70-1b的理化性质、WD重复结构域数量、亚细胞定位以及表达量和趋势,可以推测Dl MEE70-1a需要Dl MEE70-1b的协同来调控龙眼胚胎发育。
MEE70/MSI1, a maternal effect embryo arrest gene in Arabidopsis, plays an important role in plant embryogenesis. In the present study, the full-length cDNA sequences of DIMEETO-la gene （Accession number： KC492117） and its alternative splicing DIMEE70-1b （Accession number： KC492118） were obtained by RT-PCR combined with RACE techniques, while the gDNA sequence of MSI1 gene （Accession number： KC492126） was also obtained. Bioinformatics analysis indicated that both of the proteins encoded by DIMEETO-1a and DIMEETO-1b were of unstable hydrophilic and acidic proteins, mainly located in peroxisomes and the nucleus and containing 4 WD-repeat domains and 1 WD-repeat domain, respectively. Real-time fluorescence quantitative PCR analysis demonstrated that, during the somatic embryogenesis, the expression levels of DIMEE70-1a and DIMEETO-1b wre bounded at the stage of the heart-shaped embryo and displayed the trend of first-decreasing-then-rising, except for DIMEE70-1b during the period of development from the incomplete compact pro-embryogenic cultures to globular embryos. High expression of DIMEETO-1a and DIMEE70-1b in the friable-embryogenic callus was important for embryogenesis, The transcription of DIMEETO-1a was activated after the heart embryo. It was interesting that DIMEE70-1a and DIMEE70-1b had the similar physical and chemical properties, the same subcellular localization and the similar expression levels and trends. Therefore, it was inferred that DIMEE70-1b was coupled with DIMEETO-1a, possessed the coordinated regulation during the embryogenesis of longan. This study provided some new clues to the elaboration of the molecular mechanism of maternal effect genes DIMEETO in the process of somatic embryogenesis.
出处
《热带作物学报》
CSCD
北大核心
2015年第1期59-67,共9页
Chinese Journal of Tropical Crops
基金
国家自然科学基金项目(No.31272149)
福建省重大科技平台建设项目(No.2008N2001)
福建农林大学生物学博士后基金项目
