水稻CRF基因家族的鉴定与表达模式分析

Identification and expression profile analysis of rice CRF gene family

摘要:

细胞分裂素响应因子(cytokinin response factors, CRFs)作为植物特有的转录因子，在生长发育调控、激素信号通路以及胁迫应答过程中发挥着重要作用。本研究以拟南芥12个AtCRF蛋白序列为基础，通过BLAST比对，从水稻基因组中鉴定出9个CRF基因，分布于7条染色体上。利用各种在线网站和本地软件，对水稻CRF家族蛋白的保守结构域、理化性质、二级结构以及系统进化关系进行全面的解析。同时，也分析了OsCRF基因的外显子-内含子结构和启动子区顺式作用元件。结果发现，水稻CRF基因的启动子中含有大量与植物激素响应和非生物胁迫应答相关的元件。时空表达模式分析显示，4个OsCRF基因在各器官中表达量均比较低，而另外5个则高表达于水稻的叶片、花序或种子等部位。基因芯片数据表明，OsCRFs不同程度地受到脱落酸(abscisic acid, ABA)、生长素(auxin)、细胞分裂素(cytokinin, CK)以及茉莉酸(jasmonic acid, JA)的调控作用。通过分析转录组测序数据，研究还发现，OsCRF基因主要参与水稻的温度(低温及高温)胁迫应答，部分基因还参与了干旱胁迫响应，但几乎所有的基因都不响应盐胁迫。本研究为进一步解析水稻CRF家族基因的生物学功能提供了依据。

Abstract:

Cytokinin response factors (CRFs), as unique transcription factors in plants, play crucial roles in regulating development, phytohormone signaling pathway, and stress responses. In this study, we identified nine CRF genes from the rice genome by conducting a BLAST analysis using the protein sequences of twelve Arabidopsis AtCRFs. These genes are located on seven different rice chromosomes. We conducted a comprehensive analysis of the conserved domains, physicochemical properties, secondary structures, and phylogenetic relationships of rice CRF proteins using various online tools and local software. Additionally, we analyzed the exon-intron structures and cis-acting elements of OsCRFs, and found an abundance of elements relevant to phytohormone response and stress response on the promoters of rice CRF genes. Spatial-temporal expression pattern analysis revealed that four of the OsCRFs were barely expressed in all tested samples, while the other five were highly expressed in the leaf, panicle, or seed of rice. Microarray data showed that OsCRF genes are regulated to varying degrees by abscisic acid, auxin, cytokinin, and jasmonic acid. Furthermore, through analyzing the RNA-seq data, we found that OsCRFs are primarily involved in plant response to temperature stress (chilling and heat), with several OsCRFs also implicated in drought response, while hardly any respond to salt stress. This study provides an important basis for the functional characterization of rice CRF family genes.