Expression And Regulation Relationship Analysis Of Two Key PpPG Genes Related To Peach Flesh Texture And Adhension Traits

Texture and adhesion are important traits that affect the quality of the peach fruit,and it is of great significance to the consumer’s satisfaction and the postharvest storage and transportation.The fruit of the peach has the disadvantages of fast softening,short storage period.Ripening and softening is a difficult problem for peach fruit markets.In order to solve this problem,peach fruits during ripening of Okubo,08-9-106 and 08-9-107 were used as test materials to determine the flesh texture of 08-9-106 and 08-9-107.At the same time,the regulatory relationship between Ppa006857 m and Ppa006839 m was excavated based on gene cloning and transcriptional group sequencing.The main contents and conclusions are as follows:(1)The fruits of Okubo,08-9-106,08-9-107 were used as materials to analyze four traits during the late fruit development period,including fruit mesocarp firmness,flesh adhension,ethylene content,and relative gene expression.The flesh firmness decreased greatly in Okubo,with increased greatly accumulation of ethylene and higher expression of PpPG,PpACS1,and PpYUC11.Although the flesh firmness decreased rapidly,there were no significant accumulation of ethylene and related genes(PpACS1 and PpYUC11)expression in 08-9-106 peach.Compared to Okubo and 08-9-106,there were no significant increase of ethylene and gene expression which might result in the fruit firmness in08-9-107.Based on the flesh near endocarp,the Okubo was characterized as freestone with higher ethylene content and increased gene expression obviously,such as PpACS1.08-9-106 was also classfied as freestone peach,which had no rapidy ehtylene release and gene expression activation.08-9-107 was clingstone which exhibited similar characters with 08-9-106,in addition to gene expression of PpACO1 and PpYUC11 which were higher in 08-9-107.The above results show that,Okubo and 08-9-107 were freestone-melting and clingstone stony-hard phenotype respectively,which responds to ethylene.08-9-106 was freestone melting flesh phenotype that not responds to ethylene.The change of firmness of peach texture and the adhesion traits were related to the expression of PpPG gene.(2)Two PpPG genes were cloned from the peach fruits of Okubo、08-9-106、08-9-107.The gene Ppa006857 m was highly expressed with the ripening of melting flesh peach fruit,and the expression of gene Ppa006839 m was increased with the ripening of adhension stony hard peach fruit.In the case of high expression of gene Ppa006857 m,the expression of gene Ppa006839 m is relatively inhibited,except that gene Ppa006857 m does not express or Under the condition of low expression,the expression of gene Ppa006839 m was relatively high.There may be an antagonistic relationship between the two PpPG genes.