Identification and molecular characterisation of genes involved in the perennial life cycle

在驯化过程中，定向选择有利于产量较高、生命周期较短的植株。因此，如今，尽管野生作物的祖先是多年生植物，但大多数栽培作物都是一年生植物。一年生作物的种植对环境有负面影响，仅限于生长条件最佳的地区。因此，新的育种努力正瞄准多年生作物的发展。本项目以高山阿拉伯为模型，研究调控开花和多年生性状的分子机制。此前，在高山冰草中，一种正向遗传学方法导致了调控开花和促进多年生生长习性的基因的识别。在第一阶段，我建议筛选永久开花1号(PEP1)突变体的突变群体，寻找影响开花时间并对营养发育具有多效性的第二位点突变体。本研究证明，高山拟青冈中APETALA2的同源基因(AaAP2)通过春化依赖和非春化途径调控开花。AP2在春化过程中的作用以前在拟南芥中还没有报道。在第二阶段，我建议扩大对AaAP2的研究，并使用转录组图谱和染色质免疫沉淀来确定其靶点。在第一阶段，我还鉴定了三个突变体，与PEP1相比，它们促进了开花，并对花序发育具有多效性。在第二阶段，我想要分离和鉴定导致这些突变表型的基因。与一年生植物相比，许多温带多年生植物的花序发育时间不同，因此对这些基因的识别可能会对这一过程提供见解。高山十字花科植物是十字花科植物。因此，了解开花和多年生植物性状的分子调控机制可以直接应用于多年生十字花科作物的发育，并产生关于多年生植物调控原理的知识。

During the process of domestication directional selection favored plants with higher yield and shorter life cycle. Thus nowadays, most cultivated crops are annuals although their wild type ancestors are perennials. Cultivation of annual crops has negative impact on the environment and is limited to regions with optimal growth conditions. Thus new breeding efforts are aiming on the development of perennial crops. This project uses Arabis alpina as a model to study the molecular mechanisms that regulate flowering and perennial traits. Previously, a forward genetics approach in A. alpina resulted in the identification of genes that regulate flowering and contribute to the perennial growth habit. In the first phase I proposed to screen a mutagenised population of the perpetual flowering 1 (pep1) mutant and look for second-site mutants that affect flowering time and have pleiotropic effects on vegetative development. This study demonstrated that the A. alpina orthologue of APETALA2 (AaAP2) in A. alpina regulates flowering though a vernalisation -dependent and -independent pathway. The role of AP2 in vernalisation has not been previously reported in Arabidopsis thaliana. In the second phase I suggest to extend the study on AaAP2 and identify its targets using transcriptome profiling and Chromatin Immunoprecipitation. In the first phase I also identified three mutants that accelerate flowering compared to pep1 and have pleiotropic effects on inflorescence development. In the second phase I would like to isolate and characterise the genes responsible for these mutant phenotypes. The timing of inflorescence development in many temperate perennials differs compared to annuals and therefore identification of these genes might give insights on this process. A. alpina is a member of the Brassicaceae family. Therefore, understanding of the molecular mechanisms regulating flowering and perennial traits can be directly applied to the development of perennial Brassica crops and generate knowledge about the principles regulating perennialism in diverged perennials.