基于数字基因表达谱分析的茶树花不育基因挖掘

茶树每年都要开花结实,消耗大量的养分,导致茶树鲜叶产量减少和品质降低。了解茶树的不育机制有助于培育茶树不育品种。本研究以福鼎大白茶(父本)、佛香2号(母本)及其杂交后代(不育)茶树花为材料,利用数字基因表达谱技术对3个茶树花的c DNA文库进行差异基因表达谱分析。筛选出在父本花与子代不育花、母本花与子代不育花之间共有而在父本花与母本花之间没有的差异表达序列1219条,被认为是茶树不育性候选基因。GO功能显著性分析表明,这些基因功能中代谢过程、催化活性、水解酶活性表现为富集;KEGG代谢分析表明,差异表达基因涉及氨基酸、糖、次生代谢、植物信号传导途径以及能量代谢等过程。以植物激素信号转导通路分析发现,16个与生长素信号途径相关基因中,除5个ARF家族基因在子代不育花中上调表达外,其他的基因均下调,推测生长素信号转导是茶树花不育的重要因素。随机抽取5个基因进行实时荧光定量PCR验证,其结果与测序结果一致。本研究发现的不育候选基因可用于茶树花不育机制的深入研究和不育基因的筛选。

Exploring Sterility Gene from Tea Plant Flower Based on Digital Gene Expression Profiling

Tea tree (Camellia sinensis) blossoms every year and a lot of nutrients are consumed by itself during blooming and fruiting, resulting in decreased yield and quality of fresh tea leaf. In the present study, the flowers of Fuding Dabaicha (male parent), Foxiang 2 (female parent) and their hybrid (sterile flowers) were used to construct cDNA libraries and the gene expression profiles were analyzed by Solexa sequencing technology. A total of 1219 candidate sterility genes were identified according to their differential expression between the male/female parent and the hybrid but identical between the two parents. These sterility gene were subject to GO analysis, and metabolic process, hydrolase activity and catalytic activity were enriched. KEGG pathway analysis showed that the sterility genes were involved in biosynthesis of amino acids and carbohydrate, second any metabolism, plant hormone signal transduction, and energy metabolism. In the function group of plant hormone signal transduction, 16 annotated genes were involved in the auxin signal transduction pathway, including five up-regulated AFR genes in the hybrid and 11 down-regulated genes. Thus, we speculate that auxin signal transduction might regulate the flower sterility in tea tree. Five sterility genes were selected randomly for qRT-PCR assay and the result was consistent with that of Solexa sequencing. The candidate sterility genes found in this study are worthy of sterile mechanism research in tea plant and sterility gene screening.