麻疯树miR156及其靶基因的鉴定与生物学功能分析

麻疯树是我国重点开发的绿色能源树种，但因种子产量低而导致其推广应用受到一定程度限制，故亟待开展遗传改良。目前研究多集中于传统选育及油脂代谢相关编码蛋白的基因的分离和鉴定等分子辅助育种方面，而对小分子RNA的了解非常欠缺。非编码RNA-miR156主要控制植物年龄依赖的从营养期到生殖期的转变，并可用于调控花期和增强抗逆性等多个方面。基于麻疯树全基因组序列信息，本研究在构建高质量转录组的基础上，利用高通量测序技术，通过生物信息学分析，系统挖掘并鉴定麻疯树miR156及其靶基因；而后通过定量PCR检测技术，分析miR156及其靶基因在不同发育阶段及组织中的时空表达模式；最终利用遗传操作手段特异性调节miR156及其靶基因的表达量，从表型、细胞和分子水平分析并鉴定miR156在调控麻疯树生长发育和逆境响应中的生物学功能。研究结果对于进一步开展基因工程和加强分子辅助育种研究有着重要的理论和实践意义。

Jatropha curcas L. is an important green energy species that is well developed for the production of biodiesel in China; however, the development and utilization of this plant has been limited to some extent due to low yield of seeds. Therefore it’s both necessary and important to carry out genetic improvement. The investigations thus far confined to traditional breeding and identification of the role of protein-coding genes related to lipid synthesis and metabolism etc. The role of small RNA is still unknown. Non-coding RNA-miR156 defines an age-dependent flowering pathway in plants that mainly control plant juvenile to adult phase transition and can be manipulated to control flowering time and enhance resistance to abiotic stress etc. In this study, we systematically identify miR156 and its targets in J.curcas by using high-throughput sequencing technology and bioinformatics analysis in combination with construction of transcriptome of high quality on the basis of genome sequence information of J.curcas. Then we analyze the expression patterns of miR156 and its targets in different tissues and developmental stages by quantitative PCR. Furthermore, we investigate the biological function of miR156 in the regulation of developmental timing and abiotic response of J.curcas at the level of phenotype, cell and molecules by strategy of genetic manipulation to control the level of expression of miR156 and its targets. These results are significantly meaningful in theory and practice for further research about genetic engineering and molecular assisted breeding.