摘要
以番茄‘Micro-Tom’为材料,研究了生长素响应因子基因Sl ARF12(序列号:HM565127.1)在果实发育过程的生物学功能。实时定量PCR检测表明,Sl ARF12在花蕾中表达量逐渐降低,而在授粉后的子房中显著高于去雄后未授粉的子房。利用RNA干扰(RNAi)技术抑制Sl ARF12表达,对番茄植株营养生长与花的发育没有显著影响,但Sl ARF12 RNAi果实显著大于野生型与空载转化植株的果实,且开花前去雄未授粉不能形成单性结实的果实。利用半薄切片观察转基因番茄果实早期发育细胞学特性发现,转化植株的果实果皮细胞显著大于对照果实细胞,但是两者果皮细胞层数没有显著差异。基因表达分析发现在Sl ARF12 RNAi的子房与幼果中细胞分化相关基因Cyc B1.1和CDKB2.1等的表达水平同对照相比下降,而Sl PEC等细胞膨大基因表达量显著高于对照。所以抑制Sl ARF12可增强果实中细胞膨大相关基因的表达,从而促进果实膨大。以上结果表明,Sl ARF12可负调控番茄果实膨大但不参与坐果启动调控过程,显示了生长素通过ARF信号精细调控果实发育的各个阶段。
In order to explore the molecular mechanism by which auxin signal transduction mediates fruit set and development,we used tomato variety‘Micro-Tom＇to evaluate the biological function of an auxin responsive factor,Sl ARF12（HM565127.1）,in fruit development. Real-time PCR analysis showed that the Sl ARF12 m RNA levels gradually decreased before the flower was fully open,however,it became significantly higher in self-pollinated ovaries than that in emasculated and unpollinated ones. Inhibition of Sl ARF12 by RNA interference（RNAi）method had no significant influence on tomato vegetative growth and flower development,but the RNAi fruits in transgenic plants were significantly larger and heavier than those in wild-type plants and empty vector transgenic lines. In addition,no parthenocarpic fruit was developed after artificial emasculation before anthesis. The semi-thin section was performed to compare cytological characteristics in early fruits between RNAi and wild-type plants. The fruit pericap cells of transgenic lines were significantly larger than those of wild-type fruits,but the number of pericap cell layers of transgenic fruit was similar to that of the control fruit. Gene expression analysis showed that the m RNA levels of cell differentiation genes including Cyc B1.1 and CDKB2.1 in the ovary and young fruit of Sl ARF12 RNAi transgenic plants decreased when compared with the wild-type fruits,but the expression level of cell expansion gene such as Sl PEC was significantly higher than that of the control fruit. Therefore,the inhibition of the Sl ARF12 expression level would up-regulate the expression levels of cell expansion genes,which might enhance the ability of fruit expansion and result in larger fruits of transgenic plants. The data suggest that Sl ARF12 can negatively regulate the fruit expansion process in tomato but is not required for fruit initiation,revealing the auxin can finely regulate fruit development at various stages through ARF signal conduction pathway.
作者
刘松瑜
闫艳秋
冯秋硕
卢钢
LIU Songyu;YAN Yanqiu;FENG Qiushuo;and LU Gang(Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China)
出处
《园艺学报》
CAS
CSCD
北大核心
2018年第4期678-690,共13页
Acta Horticulturae Sinica
基金
国家自然科学基金项目(31471878)
浙江省重点创新团队项目(2013TD05)
浙江省自然科学基金重点项目(LZ17C150002)
