Cloning And Expression Of MYB10Transcription Factors In Fruits Of Prunus Tomentosa Thunb

Prunus tomentosa Thunb is often used as rootstock of grafting Prunus avium becauseof the character of high survival rate and strong stress resistance. Fruits of Prunustomentosa Thunb has two flavors: red and white, early maturing, high mineral elements.There are some difference in physiological traits between them. This study explored thephysiological and molecular levels in order to reveal the difference of two varieties. Fruitquality, anthocyanin content and related enzymes were measured in Prunus tomentosaThunb in physiological level and the full-length cDNAof MYB10was isolated in order tocompare of the two sequences and the gene expression level. The results are shown asfollows:1. The difference of development of flowers and fruits between red and white cherrywere observed. Petals was prink. Fruit peels was slightly dull red and turned flesh redgradually during development in red cherries. After mature turned red; but not found inwhite cherries which petals was white and fruits turned green to milky white after ripe. Itmature was about7days later than the red. Fruit quality of different cherries wasmeasured. The results showed that the white fruit quality of Vc, soluble sugar,sugar-acidratio and content were significantly higher than in red expecially Vc and titratable acidity.2. Anthocyanin content and related enzymes activities were measured in red andwhite Prunus tomentosa Thunb. The anthocyanin of cortex displayed a different changetrend at different developmental stages in two varities. Anthocyanin content graduallyelevated to33.6U· g-1FW after2weeks full bloom, and then declined lightly. Until5weeks full bloom anthocyanin content increase rapidly even in mature fruits to70.9U· g-1FW which was very significantly higher than that in white5.1U· g-1FW.Activities of PAL, CHI and DFR have the same trend between the two materials.Activities of PAL was highest after full bloom and then declined rapidly until2weeksafter full bloom, then increased slowly up to4weeks after full bloom tending to decline.Activities of CHI increased rapidly after2weeks after full bloom until the higest5weeks after full bloom and then declined rapidly. Activities of DFR gradually declined during thedevelopment of fruits,3weeks after full bloom turned the higest, then declined rapidlyuntil mature. PAL and CHI activities were significantly higher in red variety than in white,DFR activities only in fruit expanding period have the same.3. Primers were designed according to the conservative sequence of the cDNAregions of MYB10of Prunus dulcis, Prunus avium, Prunus cerasus,Prunus domesticaand Prunus salicina. The coding regions of the genes was isolated from two varieties. Theboth full-length cDNA of MYB10is927bp. Its ORF was747bp and encoded apolypeptide containing248amino acid residues.Sequence of MYB10had98%identity intwo varieties. There are differences in84,85,163,172,489,544,755,852at the baseleading to five amino acid residues difference. They were Gln,Gly,Tyr,Lys,Ile in white. Inred His, Arg, Asn, Gln, Thr.4. Real time quantitative RT-PCR analysis indicated that the expression of MYB10incortex of two varieties. The expression of MYB10showed an increasing pattern a‘low-high–low-high’ change trend in cortex during fruit development. While theexpression level of MYB10in white was very low and few the expression of MYB10wasin cortex.