Cloning And Expression Of Vernalization Gene R VRN2in Wheat(Triticum Aestivum L.)

Six wheat (Triticum aestivum) cultivars with different vernalization traitswere analyzed in this paper. Mutation of three key sites in the43amino acidsequences of the conserved CCT domain in the ZCCT1and ZCCT2genes wereanalyzed using the RT-PCR amplification. Promoter region of six cultivars werecloned and sequence features were analyzed.This paper analyzed expression featuresof ZCCT genes in vernaliazation process of Liaochun10hao and Jing841.The mainresults were summarized as followas:1. Six wheat (Triticum aestivum) cultivars with different vernalization traits wereanalyzed. Mutation of16/35/39three key sites in the43amino acid sequences of theconserved CCT domain in the ZCCT-A1/A2、ZCCT-B1/B2and ZCCT-D1/D2geneswere analyzed using the RT-PCR amplification. The results showed that6cultivarshad different mutation in CCT domain of ZCCT-A1gene, Feimai had R35W mutation,the other five cultivars had R39C mutation in ZCCT-A1. while all of the6cultivarshad R16C mutation in ZCCT-A2gene. B and D genomes of the6cultivars had nomutations. Allelic variation of VRN2coding region is mainly refiected in the Agenome, while VRN2in B、D genome is dominant in the tested cultivars.2. Expression features of ZCCT-A1/A2、ZCCT-B1/B2and ZCCT-D1/D2genes invernaliazation process of Liaochun10hao and Jing841were analyzed bysemi-quantitative RT-PCR technique. The results showed that ZCCT-A1/A2had lowerexpression levels. The expression levels of ZCCT-B1/B2and ZCCT-D1/D2graduallydecreased with the increase of vernalization days. And he expression levels ofZCCT-B1was higher. Moreover, the expression levels of Jing841were signicantlyhigher than Liaochun10hao’ showed that the inhibition vernalization of VRN2genesfrom winter cultivars were significantly greater than that from spring cultivars in thetested cultivars.3. Promoter region of six cultivars were cloned using the sequence-specific PCRamplification and sequence features were analyzed. The results showed that target bands of six cultivars were amplified, and all were not null form. There wee threeSNPs in ZCCT-A1promoter,and three SNPs in ZCCT-D1promoter. Except Zhengmai9023, the other five varieties have three consecutive TCT repeat sequence inZCCT-A1promoter upstream97bp. While the six varieties have two consecutive TCTrepeat sequence in ZCCT-B1promoter upstream97bp. The six varieties delete oneTCT sequence in ZCCT-B1promoter, we speculate that this delection can be used asmolecular marker of ZCCT-B1. As the delections emerge in promoter region, whetherthere have ralationship between the delection and the strength of the winterdevelopmental characteristics, this requires further studies.