摘要
为探究猕猴桃果实中bHLH转录因子的功能,本试验从青皮红香猕猴桃(Actinidia chinensis Qingpihongxiang)中克隆得到bHLH家族基因AcbHLH137,并对该基因的功能进行初步分析。结果表明,AcbHLH137(PSR95969.1)含有长度为969 bp的开放阅读框(ORF),共编码323个氨基酸。AcbHLH137蛋白分别含有碱性区(basic)和螺旋-环-螺旋区(HLH)2个高度保守的结构域,同茶树(CsbHLH137,XP;28125498.1)的氨基酸序列具有较高的相似性,达98%。亚细胞定位结果表明AcbHLH137定位于细胞核。qRT-PCR结果表明,AcbHLH137在猕猴桃成熟果实和茎中表达量最高,AcbHLH137基因的表达量在采后贮藏期间呈上升趋势。AcbHLH137在烟草叶片中瞬时过表达降低了烟草叶片中淀粉的含量,提高了β-淀粉酶基因NbBAM3的表达量。LUC/REN双荧光素酶试验结果表明,AcbHLH137转录因子能激活AcBAM3启动子。由此推断,AcbHLH137转录因子可通过激活AcBAM3基因表达,促进果实淀粉降解,从而加速猕猴桃果实后熟软化。本研究结果为揭示AcbHLH137转录因子对淀粉降解的转录调控功能奠定了理论基础。
To investigate the function of bHLH TFs of kiwifruit,the AcbHLH137 gene was cloned from Actinidia chinensis Qingpihongxiang and its gene function was preliminarily analyzed.The results showed that the AcbHLH137 gene has an open reading frame(ORF)of 969 bp,encoding 323 amino acids.It is mainly composed of basic region and helix-loop-helix region.The similarity between AcbHLH137 protein and the CsbHLH137 of tea plant is 98%.The results of subcellular localization showed that AcbHLH137 was localized in the nucleus.The results of qRT-PCR demonstrated that the expression of AcbHLH137 in mature fruits and stems was higher than in any other tissues and showed an up-regulated pattern during the postharvest storage of kiwifruit.The transient overexpression of AcbHLH137 in tobacco leaves reduced the starch content,which was associated with the increased transcripts ofβ-amylase gene NbBAM3.It was shown that the transcriptional activities of AcBAM3 could be activated by AcbHLH137 according to the results of the LUC/REN dual luciferase assay.Therefore,it can be concluded that AcbHLH137 transcription factor promotes starch degradation by activating the expression of AcBAM3 gene,thus accelerating the ripening and softening of kiwifruit.Our results will provide a theoretical basis for revealing the transcriptional regulatory of AcbHLH137 transcription factor on kiwifruit starch degradation.
作者
刘璐
王康
韩一璐
杨民杰
陈伟
曹士锋
施丽愉
LIU Lu;WANG Kang;HAN Yilu;YANG Minjie;CHEN Wei;CAO Shifeng;SHI Liyu(College of Biological and Environmental Sciences,Zhejiang Wanli University,Ningbo,Zhejiang 315100)
出处
《核农学报》
CAS
CSCD
北大核心
2022年第3期544-553,共10页
Journal of Nuclear Agricultural Sciences
基金
浙江省重点研发计划项目(2019C02079)
浙江省“生物工程”一流学科学生创新计划项目(CX20102)
宁波市自然科学基金项目(2018A610222)。
关键词
猕猴桃
bHLH转录因子
淀粉降解
转录调控
kiwifruit
bHLH transcription factors
starch degradation
transcriptional regulation
