Cloning And Expression Analysis Of Malate Transporter In Plum Fruit And Analysis Of The Correlation Of Organic Acids

Organic acid is a major factor to determine the quality of fruit.It is involved in the formation of fruit flavor,color and aroma.Its composition,transport and accumulation mechanism in fruit has traditionally been an important subject of fruit quality research.In the fruit cells,the malate transport protein tDT(tonoplast decarboxylate transporter)and the malate transport ion channel protein ALMT(almuminum-activated malate transporter)gene family mediates the transport of malic acid in the cytoplasm and accumulates the organic acid And degradation mechanism research is of great significance.In this study,four representative varieties of 'Crown','Xigua','Black Amber' and 'Elodrao' were utilized to analyze content of organic acid in fruit by ultra performance liquid chromatography(UPLC).The expression of tDT-like,ALMT4-like and ALMT9-like genes were detected in four representative cultivars by real-time fluorescence quantitative PCR.The expression of malate transporter and the organic acid components in the fruit of the fruit were analyzed by pearson correlation analysis and regression modeling.The main results were as follows:1.The pH change of plum fruit during development was obvious V-type in Black amber,Crown and Xigua,but in Elodrao little change.The pH value in maturity fruit was shown Elodrao>Black Amber ? Xigua>Crown,a little difference at the end of ripening fruits for Elodrao>Black Amber>Crown ? Xigua.The obviously inverted V-type of TA changes in the fruit of Black amber,Crown and Xigua were shown.But there was little change in Elodrao fruit.The value of TA in the mature and ripening fruits was shown in Xigua>Crown>Black Amber>Elodrao.The difference of high or low acid varieties was due primarily to the rapid or longer acid degradation of low acid varieties,and the acid degradation slowed down or the time was shorter.2.Malic acid is the main organic acid in plum fruit,accounting for 57%?84%of the total acid content,plum is a typical malic acid type fruit.followed by tartaric acid,individual varieties(such as Xigua)up to 18%to 36%.And the fruit of citric acid,succinic acid,oxalic acid,acetic acid,fumaric acid only in small or trace.The content of malic acid in fruit was shown in Crown>Xigua ? Black Amber>Elodrao.3.The effect of malate transporter gene on malic acid in plum cultivars was different.The tDT-like gene was shown a positive role in the regulation of fruit acid accumulation in high malic acid content(such as Crown and Xigua),and the regulation of low malic acid content(such as Elodrao)is not obvious.ALMT9-like gene had a negative effect on the accumulation of malic acid in different cultivars.The ALMT4-like gene was indicated a positive role in the accumulation of malic acid in Crown,Xigua and Elodrao,but there was a negative role in the accumulation of malic acid in Black Amber.4.The association between malic acid transporter and organic acid component was shown that ALMT4-like and ALMT9-like genes could be involved in the transport of other organic acid components in the transport of malic acid.ALMT9-like gene was significantly associated with malic acid and succinic acid.ALMT9-like gene was significantly associated with malic acid and citric acid,also significantly correlated with oxalic acid.Indicating that the protein of ALMT4-like may also participate in the transport of malic acid and succinic acid.And the protein of ALMT9-like may also participate in the transport of malic acid,citric acid and oxalic acid.