Evolutionary and functional analysis of mulberry type III polyketide synthases

BMC Genomics

Research Article

Guangyu Ding¹  Hu Chen¹  Bi Ma¹  Jiubo Liang¹  Ningjia He¹  Han Li¹ 

[1] State Key Laboratory of Silkworm Genome Biology, Southwest University, Beibei, 400715, Chongqing, People’s Republic of China;

关键词: Chalcone synthase;    Stilbene synthase;    Functional analysis;    Evolutionary analysis;    Gene expression;    Mulberry;   

DOI  :  10.1186/s12864-016-2843-7

 received in 2016-01-26, accepted in 2016-06-16,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundType III polyketide synthases are important for the biosynthesis of flavonoids and various plant polyphenols. Mulberry plants have abundant polyphenols, but very little is known about the mulberry type III polyketide synthase genes. An analysis of these genes may provide new targets for genetic improvement to increase relevant secondary metabolites and enhance the plant tolerance to biotic and abiotic stresses.ResultsEighteen genes encoding type III polyketide synthases were identified, including six chalcone synthases (CHS), ten stilbene synthases (STS), and two polyketide synthases (PKS). Functional characterization of four genes representing most of the MnCHS and MnSTS genes by coexpression with 4-Coumaroyl-CoA ligase in Escherichia coli indicated that their products were able to catalyze p-coumaroyl-CoA and malonyl-CoA to generate naringenin and resveratrol, respectively. Microsynteny analysis within mulberry indicated that segmental and tandem duplication events contributed to the expansion of the MnCHS family, while tandem duplications were mainly responsible for the generation of the MnSTS genes. Combining the evolution and expression analysis results of the mulberry type III PKS genes indicated that MnCHS and MnSTS genes evolved mainly under purifying selection to maintain their original functions, but transcriptional subfunctionalization occurred during long-term species evolution. Moreover, mulberry leaves can rapidly accumulated oxyresveratrol after UV-C irradiation, suggesting that resveratrol was converted to oxyresveratrol.ConclusionsCharacterizing the functions and evolution of mulberry type III PKS genes is crucial for advancing our understanding of these genes and providing the basis for further studies on the biosynthesis of relevant secondary metabolites in mulberry plants.

【 授权许可】

CC BY   
© The Author(s). 2016