Effects of perturbing polyamine metabolism on development and stress responses in Arabidopsis thaliana

迫切需要了解植物的发育和对压力的反应，以最大限度地提高作物产量并确保粮食安全，特别是在面临气候变化的情况下。植物激素在调节植物开花、种子发育以及对环境胁迫和病原体的反应中起着关键作用。多胺是一种重要的代谢物，具有类似植物激素的作用，但其在植物发育中的确切作用尚不清楚。多胺体内平衡是通过生物合成和分解的平衡以及不同多胺之间的相互转化来维持的。铜胺氧化酶（CuAOs）是一个分解代谢多胺的相关酶家族，在植物逆境响应和植物发育中发挥重要作用。在模式植物拟南芥中，多胺水平似乎也会影响其他植物激素，如赤霉素酸（GAs）——植物生长和繁殖的关键调节剂。初步数据表明，多种CuAOs的下调会导致开花时间、植物结构和种子产量的变化。本项目将利用人工微rna、CRISPR/Cas9和T-DNA插入模式植物拟南芥中产生的CuAO突变体，在表型和细胞水平上研究单个或多个CuAO基因突变对拟南芥的影响。一个主要目标是更好地了解多胺和GAs如何相互作用。这将通过生化分析突变体不同器官中GA和多胺含量与野生型的比较，对细胞结构的影响，以及通过突变体的转录组学分析来确定目标基因来进行探讨。因此，该项目将在四个关键领域提供培训，为学生发展自己的兴趣留下空间：(1)质粒载体构建，包括CRISPR构建和植物转化；(2)代谢物和植物激素的生化分析；(3)通过无菌培养、显微镜、转录组学和代谢组学分析转基因品系的发育和胁迫反应；(4)大数据集的统计分析

There is an urgent need to understand plant development and responses to stresses to maximise crop production andensure food security, especially in the face of climate changes. Plant hormones play key roles in regulating flowering,seed development and responses of plants to both environmental stresses and pathogens. Polyamines areessential metabolites that have some roles that resemble plant hormones, but their exact role in plant development isunknown. Polyamine homeostasis is maintained by a balance of biosynthesis and breakdown as well as interconversionamongst different polyamines. Copper amine oxidases (CuAOs) form a family of related enzymes that catabolisepolyamines and have a role in plant stress responses and in plant development. In the model plant, Arabidopsis,polyamine levels also seem to affect other plant hormones such as gibberellic acids (GAs) - key regulators of plantgrowth and reproduction. Initial data indicate that down-regulation of multiple CuAOs results in changes to floweringtime, plant architecture and seed production.Using CuAO mutants generated through artificial micro RNAs, CRISPR/Cas9 and T-DNA insertions in the model plantArabidopsis thaliana, the project will investigate the effects of mutating single or multiple CuAO genes in Arabidopsisat a phenotypic and cellular level. A major goal is to gain a better understanding of how polyamines and GAs interact. Thiswill be explored through biochemical analyses of GA and polyamine content in different organs of mutants compared towild type, effects on cellular structure, and through transcriptomic analysis of mutants to identify target genes. Theproject will therefore provide training in four key areas leaving space for the student to develop their own interests:(1) plasmid vector construction including CRISPR constructs, and plant transformation(2) biochemical analysis of metabolites and plant hormones(3) Analysis of development and stress responses in transgenic lines through sterile culture, microscopy, transcriptomicsand metabolomics(4) statistical analysis of big data sets