龙眼花色素苷生物合成相关基因DlCHS9的序列与功能分析  

Sequence and Function Analysis of DlCHS9 Related to Anthocyanin Biosynthesis in Longan

作　　者：李艳红 蔡芹 沈薇 杜丽娜 陈哲[1] 谭芳 赖彪 胡福初[1] LI Yanhong;CAI Qin;SHEN Wei;DU Lina;CHEN Zhe;TAN Fang;LAI Biao;HU Fuchu(Institute of Tropical Fruit Trees,Hainan Academy of Agricultural Sciences/Key Laboratory of Genetic Resources Evaluation and Utilization of Tropical Fruits and Vegetables(Co-construction by Ministry and Province and Ministry of Agriculture and Rural Af-fairs)/Key Laboratory of Tropical Fruit Tree Biology of Hainan Province/Haikou Scientific Observation and Experimental Station for Tropical Fruit Trees,Ministry of Agriculture and Rural Affairs,Haikou,Hainan 571100,China;School of Advanced Agricul-ture and Bioengineering,Yangtze Normal University,Chongqing 408100,China)

机构地区：[1]海南省农业科学院热带果树研究所/农业农村部热带果蔬遗传资源评价利用重点实验室(部省共建)/海南省热带果树生物学重点实验室/农业农村部海口热带果树科学观测实验站,海南海口571100 [2]长江师范学院现代农业与生物工程学院,重庆408100

出　　处：《热带作物学报》2024年第11期2298-2304,共7页Chinese Journal of Tropical Crops

基　　金：海南省热带果树生物学重点实验室开放课题项目(No.HAAS2022PT0109);重庆市现代农业产业技术体系项目(No.COMAITS202305);重庆市教育委员会科学技术研究项目(No.KJQN202101442)。

摘　　要：查尔酮合成酶(chalcone synthase,CHS)是植物类黄酮化合物合成途径的第一个关键酶。前期在龙眼(Dimocarpus longan Lour.)中鉴定了与花色素苷合成密切相关的DlCHS9,发现与红皮龙眼相比,其在石硖龙眼果皮中的表达水平较低。为了进一步探究DlCHS9的生物学功能,本研究分别克隆石硖龙眼DlCHS9-SX和红皮龙眼DlCHS9-HP基因,氨基酸序列比对分析发现,二者仅在第328位氨基酸位点有差异,但该位点并不是关键酶活性位点。进一步构建植物表达载体,并采用农杆菌介导的叶盘法将DlCHS9-SX转入烟草。结果表明,转基因烟草花瓣更红,花色素苷含量更高,说明DlCHS9-SX超表达能促进烟草花瓣花色素苷的积累。分析DlCHS9的启动子序列表明,相似度为96.2%,与DlCHS9-HP的启动子相比,DlCHS9-SX的启动子有32个SNP、14个碱基插入和12个碱基删除,多1个脱落酸响应元件(ABRE),少1个光反应元件(Box4)、1个低温响应元件(LTR)和1个MYC转录因子结合元件。综上所述,DlCHS9-SX是石硖龙眼花色素苷合成的关键结构基因之一,而其启动子序列与红皮龙眼差异较大,可能是其在石硖果皮中表达较低的重要原因之一。Chalcone synthase is a crucial enzyme in the initial stage of the flavonoid biosynthetic pathway.To explore the biological functions of our previously identified chalcone synthase coding gene DlCHS9 from longan,which is as-sociated with anthocyanin accumulation,DlCHS9-SX and DlCHS9-HP from Shixia and Hongpi longan,were cloned respectively.Amino acid sequences of DlCHS9-SX and DlCHS9-HP were compared and found to differ only at position 328,which was not a key active site.Subsequently,an expression vector was created,and the Agrobacterium-mediated leaf disc method was used to introduce DlCHS9-SX into wild tobacco.The anthocyanin content in the petals of transgenic tobacco was notably higher than that in the wild type,suggesting that the DlCHS9-SX gene enhances an-thocyanin accumulation in tobacco petals.The promoter sequences of the two DlCHS9 genes revealed a similarity of 96.2%.Compared to the promoter of DlCHS9-HP,the promoter of DlCHS9-SX had 32 SNPs,14 base insertions,and 12 base deletions.Specifically,the DlCHS9-SX promoter contained an additional abscisic acid responsive element(ABRE),one fewer light-responsive element(Box4),one less low temperature-responsive element(LTR),and one less MYC transcription factor binding site.In conclusion,DlCHS9-SX plays a pivotal role as a structural gene in longan anthocyanin biosynthesis.The differences in the DlCHS9 promoter in Shixia longan may contribute to its lower expression level.

关 键 词：龙眼 DlCHS9 烟草 花色素苷 

分 类 号：S667.2[农业科学—果树学]