ABSTRACT

Orchid flowers have unique floral organisation which make them indispensable to the floral industry. The MADS-box gene family encodes for transcription factors that are involved mainly in floral organisation. This study was conducted on Vanilla planifolia, which is an important orchid that is commercially exploited by the food industry for a highly valued flavour, vanillin. V. planifolia transcriptome was analysed and 33 MADS-box transcripts that encode putative MADS-box proteins, were identified. Phylogenetic analysis of the VpMADS proteins with other closely related plant species showed clear clustering into type I and type II. Protein characterisation, duplication events, and their evolutionary analysis were performed. The spatio-temporal expression profile for VpMADS genes at different plant developmental stages showed high expression of these genes in specific floral tissues. Secondary and tertiary structural analyses was also done for 13 MADS-box proteins representing each sub-class and their 3D structures were deduced. This study provides a basic understanding of the functioning of MADS-box gene family in V. planifolia and paves the path for functional characterisation of selected VpMADS genes in planta and in a heterologous system for managing the commercially important traits in this orchid.

摘要

兰花花具有独特的花组织，这使其成为花卉行业必不可少的。MADS-box基因家族编码主要参与花卉组织的转录因子。这项研究是在香草兰上进行的，香草兰是一种重要的兰花，食品工业对其进行了商业开发，获得了高价值的香兰素。分析了V.planifolia转录组，并鉴定了33个编码假定的MADS-box蛋白的MADS-box转录本。对VpMADS蛋白与其他密切相关的植物物种进行的系统进化分析显示，其明显聚集为I型和II型。进行蛋白质表征，复制事件及其进化分析。VpMADS的时空表达谱在植物不同发育阶段的基因显示出这些基因在特定花卉组织中的高表达。还对代表每个亚类的13种MADS-box蛋白进行了二级和三级结构分析，并推导了其3D结构。这项研究提供MADS-box基因家族在运作的一个基本的了解五荚兰和铺平了道路的选择功能特性的路径VpMADS基因在植物和对该兰花管理重要商业价值的性状的异源系统。