miRNA169介导NAT调控植物适应干旱胁迫分子机制的研究

cis-natural antisense transcripts (cis-NATs) have been found in many eukaryotic organisms. In Arabidopsis, 1340 potential cis-NAT pairs have been predicted, and 957 cis-NATs are confirmed by analysis of full-length cDNAs and massively parallel signature sequencing data. Some of the cis-NAT pairs show anti-correlated expression patterns and small RNAs derived from the cis-NATs have been observed, which may account for the anti-correlated expression; However, independent researchers reported that cis-NATs did not tend to produce nat-siRNAs when compared to non-overlapping neighboring gene pairs, and anti-correlated expression of cis-NATs only represented a small number of the total cis-NATs.Thus, the mechanisms by which NATs regulate gene expression are still far beyond understood. We previously reported that NFYA5 was an important drought stress inducible transcription factor gene that was targeted by miR169 in Arabidopsis. The 3′ UTR of NFYA5 overlaps with that of At1g54150, which we named as NFYA5 Enhancing RING FINGER (NERF). Interestingly, overexpression of NERF led to enhanced transcript levels of NFYA5 and repression of miR169, indicating that NERF could fine regulate the expression of miR169 to affect NFYA5 transcripts. In the present project,we plan to utilize NERF/NFYA5 gene pair as an example to classify the potential relationship between NAT and microRNA through the technogies of RNomics, bioninformatics, molecular biology and biochemstry. Our research will significantly contribute to the understanding of the NATs with positively correlated expression patterns, and provide valuable information for breeding abitotic-stress-resistance cultivar.

NATs（Natural Antisense Transcripts）广泛存在于真核生物，但相关功能及其调控机制还不清楚。我们已发表的结果证实NFYA5及miR169在植物感受干旱胁迫信号转导通路中处于重要地位；深入研究NFYA5功能时发现NFYA5与NERF形成NAT，其在35S::NERF转基因植株中的表达量显著上升，而作为转录后水平调控NFYA5 表达的主要调节子miR169的表达显著降低,暗示NERF可能通过对miR169进行精细调控影响NFYA5表达，进而参与植物适应干旱胁迫反应。因此本申请拟在现有工作基础上，以NERF/NFYA5基因对为例，深入研究NAT与microRNA的互作关系及其这种互作关系的生物学功能。通过对这种复杂调控网络的分析与深入了解，有助于我们理解在特定环境与发育时期表达量一致的NAT的调控机制，最终为培育抗逆作物品种打下坚实的分子生物学基础。

NATs（Natural Antisense Transcripts）广泛存在于真核生物，但相关功能及其调控机制还不清楚。我们运用小RNA技术、生物化学及其分子生物学等手段深入研究NERF与miR169在调控靶基因中可能存在的互作关系，发现NERF及其NFYA5的重叠区会产生与miR169序列类似的siRNANERF，它可以竞争性的结合miR169与其靶基因NFYA5的作用位点，进而影响miR169对于NFYA5的切割。通过对这种复杂调控网络的分析与深入了解，有助于我们理解在特定环境与发育时期表达量一致的NAT的调控机制及其microRNA复杂的作用方式，进而为培育抗逆作物品种打下坚实的分子生物学基础。在本项目的资助下，在Nucleic Acids Resrearch、New Phytologist、Plant Journal、BMC Plant Biology等SCI杂志发表论文四篇，均为第一标注。已培养博士生2名，硕士生1名，在读博士生1名。本人入选2016年度科技部“创新人才推进计划中青年科技创新领军人才”。