生长素酰胺水解酶基因在西瓜果实发育过程中的表达  

Expression Analysis of IAA-amino Acid Hydrolases Genes in the Development of Watermelon Fruits

作　　者：高嫱 田守蔚 张洁[2] 王艳萍 孙宏贺[2] 张海英[2] 许勇[2] 宫国义[2] 周明[2] GAO Qiang;TIAN Shou-wei;ZHANG Jie;WANG Yan-ping;SUN Hong-he;ZHANG Hai-ying;XU Yong(College of Plant Science and Technology,Beijing University of Agriculture,Beijing 102206,China;National Engineering Research Center for Vegetables,Beijing Academy of Agriculture and Forestry Sciences,Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(North China),Beijing Key Laboratory of Vegetable Germplasm Improvement,Beijing 100097,China)

机构地区：[1]北京农学院植物科学技术学院,北京102206 [2]北京市农林科学院蔬菜研究中心/农业部华北地区园艺作物生物学与种质创制重点实验室/蔬菜种质改良北京重点实验室,北京100097

出　　处：《黑龙江农业科学》2018年第3期19-25,共7页Heilongjiang Agricultural Sciences

基　　金：北京学者资助项目(BSP026);国家西甜瓜产业技术体系资助项目(CARS-25);北京西甜瓜创新团队资助项目(BAIC10-2017)

摘　　要：生长素在植物果实发育与成熟过程中发挥重要作用,但生长素调控西瓜果实发育与成熟的分子机制尚不十分清楚。以含糖量低的野生西瓜PI296341-FR与含糖量高的栽培西瓜97103为试验材料,测定并比较了栽培与野生西瓜果实发育不同时期果实整组织游离态IAA的含量。结果表明:果实游离态IAA的含量随西瓜果实发育而上升,在授粉后18d达到峰值,后期逐步下降。含糖量高的栽培西瓜果实游离态IAA的含量在果实发育的各个阶段,均显著高于含糖量低的野生西瓜,说明果实游离态IAA的积累可能与果实成熟及含糖量积累相关。已有研究表明生长素酰胺水解酶(IAA-Leucine Resistant1-like Hydrolase,ILR1-like hydrolase,ILL)通过催化结合态生长素释放游离态生长素,是游离态生长素积累的限速酶。在西瓜全基因组上对ILL基因家族进行了系统进化树分析,通过qRT-PCR检测了西瓜各个组织的表达情况,发现西瓜果肉中只有4个ILL基因表达,并且栽培西瓜果肉中这4个基因的表达量均显著高于野生西瓜,其中,Cla017661在栽培西瓜果肉中的表达量最高,且与果实游离态IAA的含量变化趋势正相关,推测该基因对栽培西瓜游离态IAA的积累起关键作用,进而调控了西瓜果实的发育与成熟的进化。Auxin plays an important role in the development and maturation of plant fruit,but the molecular mechanism of auxin in regulating the development and maturity of watermelon fruit is still not clear.In this study,the free IAA content of whole fruit tissue was measured and compared between cultivated watermelon 97103 which presents high sugar content and wild watermelon PI296341-FR which presents low sugar content.The results showed that in fruit the content of free IAA increased with the development of watermelon fruit,and reached its peak on the 18 day after pollination,and then gradually decreased in the later period.The free IAA content of the watermelon fruit with high sugar content was significantly higher than that of the wild watermelon with low sugar content at all stages of fruit development,indicating that the IAA accumulation of free fruit was related to fruit maturity and sugar accumulation.Studies have shown that IAA-Leucine Resistant1-like Hydrolase(ILL)which were rate-limiting enzymes in the accumulation of free auxin released free auxin by hydrolyzing IAA-amino acid hydrolases.In this study,we analyzed the phylogenetic tree of the ILL gene family in the whole genome of watermelon,and the gene expression of each tissue in watermelon by qRT-PCR.It was found that only 4 ILL genes were expressed in the flesh of watermelon,and the expression of the four genes in the cultivated watermelon was significantly higher than that of the wild watermelon.Among them,the expression of Cla017661 in the cultivated watermelon flesh was the highest,and it was positively related to the variation trend of free IAA content in the fruit,suggesting that Cla017661 was crucial in the accumulation of free IAA in cultivated watermelon and regulated the evolution of development and maturation of watermelon fruit.

关 键 词：生长素 西瓜 游离 IAA 生长素酰胺水解酶 

分 类 号：S651[农业科学—果树学]