Cloning And Expression Analysis Of MYB Transcription Factor Gene In Pepper

Capsaicin is a kind of secondary metabolites that is specific for the plant belong to Capsicum, it is also an important component of capsaicine and is the main source of piquancy of pepper as well. The synthesis and metabolism of capsaicin is mainly composing vanillylamide and C8—C11 fatty acid, and these two components are respectively derived from phenylalanine and valine. Many researches indicate that capsaicin has function in new-generation pesticide, analgesia, anti-fatigue, anti-tumor,beauty, anti-virus etc. Therefore, the research on the regulation pathway of synthesis of capsaicin is really meaningful.In our research, we obtained one full-length MYB transcription factor via PCR.This gene has full length CDS of 1038 base pairs encoding 345 amino acid residues.Through analysis of the website, this gene consists of two helix-loop-helix motif and a MYB transcription factor motif. R2R3-MYB, through homology analysis, we found this gene shares close homolog with Tomato and Solanum penellii transcription factor,MYB44-like. Using http://web.expasy.org/ analyze the protein property of this gene,the website forecasts the PI=8.57, MW=38241.06, and it’s a neutral protein with no trans-membrane structure.Using RT-PCR technique, we analyzed the time-spatial expression pattern of the already obtained MYB-transcription factor and three other capsaicin synthesis related genes(Pun1, PAL, KAS) in C.chinense Jacq’s root, stem, leaf, flower, fruit, seed,placenta and in the development stages of fruit stage, green ripe stage, turn color period, mature period. We found that this gene expresses most in seed while expresses least in flower. And as for the development stages, this gene expresses most in fruit of turn color stage. KAS expresses most in the leaf and in the fruit of turn color stage.PAL expresses most in root while least in flower, as for development stage, it expresses most in fruit of the fruit stage.Pun1 encodes acyltransferase(AT3), it’s a gene of capsaicin synthesase, it plays important role in regulation of pepper synthesis. While this MYB transcription factor share a similar expression pattern with Pun1. Thus, we deduce that this MYB transcription factor may has function in regulation of capsaicin synthesis.