缺铁诱导可变剪切的功能分析及其调控机制研究

项目名称： 缺铁诱导可变剪切的功能分析及其调控机制研究

项目编号： No.31470346

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 李文凤

作者单位： 南京林业大学

项目金额： 85万元

中文摘要： 铁是植物必需的微量元素，缺铁会造成作物减产和品质下降，而过量会对细胞有毒害。植物通过复杂的调控网络来严格控制铁的平衡。作为调控真核基因表达的重要机制，可变剪接（Alternative Splicing, AS）参与调控植物铁平衡的研究在国内外尚属空白。前期通过分析拟南芥转录组数据，发现缺铁诱导产生特异性AS，推测AS可能参与缺铁响应过程，但对缺铁诱导AS的功能和产生机制还不清楚。本项目采用分子生物学、遗传学和生物信息学等方法，进一步验证和克隆缺铁诱导差异表达的AS异构体，分析其生理功能和分子特性，并研究调控AS的顺式元件和反式因子。通过本项目，有望挖掘功能性AS异构体，阐明其在缺铁响应中的生理功能和可能的作用机制，并鉴定缺铁诱导AS的调控因子，揭示缺铁引发AS变化的分子机制。本项目的实施，将弥补当前对植物中AS认识的不足，完善对铁平衡精细调控系统的理解，为培育富铁农林作物品种提供新思路。

中文关键词： 拟南芥；矿质营养；微量元素；基因功能

英文摘要： Sophisticated regulatory mechanisms allow plants to tightly control the homeostasis of iron, ensuring sufficient amount for optimal growth while preventing excess accumulation. Alternative splicing (AS) is an important mechanism involved in regulating the gene expression. In recent years, the increasing transcriptome analysis of alternative splicing using RNA sequencing has revealed that AS is highly pervasive in plant during development and stress responses. However, the functions of most splice variants and the regulation of AS are largely unknown. Our previous study using RNA-seq technology identified iron deficiency-induced AS. In this proposal, we will identify the functional AS variants using genetic approaches and address its physiological functions in response to iron deficiency in plants. Further experiments will carry out to understand how the potential AS control transcript and expression levels under iron starvation conditions. Regulation of AS reflects the interactions between positive and negative Cis-elements in the precursor messenger RNA and a range of trans-factors. In order to elucidate the mechanisms that control iron deficiency-dependent AS changes, we will investigate known Cis-elements and search conserved motifs that significantly enriched in iron deficiency-induced AS. Known plant arginine/serine-rich (SR) proteins and heterogenous nuclear ribonucleo proteins (hnRNPs) that involved in alternative splice site regulation will be examined by loss-of-function analysis to uncover the trans-factors that affect AS changes under iron deficiency conditions. This study will shed light on the significance and regulation of AS in response to stress signals in plants, expand our knowledge to understand the fine-turning mechanism of gene activity in cellular iron homeostasis, and open new avenues to enhance plant performance.

英文关键词： arabidopsis;iron;alternative splicing;gene function