芍药内外花瓣发育形成相关基因片段的生物信息学及组织表达分析

Bioinformatics and tissue expression analysis of genes affecting the formation and development of inner/outer petal in Paeonia lactiflora

关键词:  芍药  托桂型  生物信息学  基因表达

Key words:  Paeonia lactiflora  flower type  bioinformatics  gene expression

摘要:

为揭示芍药内外花瓣形成的分子机制，以托桂型芍药品种‘紫凤羽’为材料，利用转录组测序筛选调控芍药花型发育的关键基因序列片段，首先通过生物信息学方法分析基因片段的蛋白结构与功能以及亚细胞定位，其次利用qPCR检测基因在花瓣中表达情况。结果显示，测序筛选出2个关键基因——AGAMOUS（AG）和 MADS-box protein2（MADS2），蛋白分析表明两者均为脂溶亲水性不稳定蛋白，均无剪切信号肽和跨膜结构，为非分泌蛋白，二级结构均以α螺旋（Alpha helix）为主，三维结构模型极为相似，并且包含1个相同的保守功能域-MADS，很少信号肽分泌途径上；qPCR检测显示内瓣AG与MADS2表达量均极显著高于外瓣（P<0.01）。芍药AG和MADS2蛋白结构功能、表达水平差异均存在一定的相似性，推测两者可能在芍药花瓣形成过程中发挥相同的生物学功能。

Abstract:

To reveal the molecular mechanisms of petal formation in Paeonia lactiflora,we selected inner and outer petals from P.lactiflora ‘Zi Fengyu’ with anemone type as study object.Using transcriptome sequencing,key gene sequences regulating flower type development were screened.The protein structure and function,subcellular localization were firstly analyzed by bioinformatics method,and then the expression level of petals detected by qPCR.The results showed that two key genes,namely AGAMOUS (AG) and MADS-box protein 2 (MADS2),were determined by sequencing.The protein analysis displayed that AG and MADS2 protein were liposoluble,hydrophilic and unstable.No signal peptide and transmembrane structure indicated two proteins were non-secretory. α-helices were its main elements of the secondary structure and their three-dimensional structure were very similar.Besides,AG and MADS2 protein contained same functional MADS domain.These proteins mostly distributed in other locations rather than in signal peptide secretion pathway.qPCR analysis showed the expression of MADS2 and AG in inner-petal was extremely significant than that in outer-petal.The similarity of AG and MADS2 in protein structure,function and expression suggested that the two proteins probably played same biological functions in the formation process of P.lactiflora petal.