The Regulatory Role Of Auxin Response Factor PpARF4 Interaction With PpMYB10.1 On Anthocyanin Synthesis In Peach Fruit

Peach(Prunus persica L.)is a fruit with important economic value.Improving fruit quality and enhancing market competitiveness are hot research issues in the development of the peach industry.Fruit color is one of the important quality traits of peach,and the degree of fruit coloration depends on the anthocyanin content.Anthocyanin synthesis is regulated by transcription factors such as MBW complex,and auxin participates in this regulation process.The auxin response factor PpARFs are important transcription factor in the regulation of auxin in physiological processes.In order to explore the effect of PpARFs on anthocyanin synthesis in peach fruit,in this study,'Okubo' peach was used as a test material to explore the expression patterns of PpARF4,anthocyanin synthesis and related genes,and to analyze the regulatory relationship between related factors.The findings are as follows:1.The peel of 'Okubo' peach is colored as the fruit matures.Anthocyanin(cyanidin-3-glucoside)was detected by HPLC in the late mature stage and full mature stage.20?M NAA treatment delayed the coloration of peach fruits,and auxin was presumed to inhibit the anthocyanin synthesis in peach fruits.2.The expression patterns of 9 anthocyanin-related genes PpDFR,PpANS,PpUFGT,PpMYB10.1-3,PpbHLH3,PpWD40-1 and PpARF4 were analyzed by qPCR.Combined with the determination of anthocyanin content,the transcription factor highly positively related to anthocyanin level was PpMYB10.1,and the structural genes were PpDFR and PpUFGT.PpARF4 was highly negatively correlated with anthocyanin levels,reaching 0.8480.These results indicate that PpMYB10.1,PpUFGT and PpARF4 may be directly involved in the synthesis of anthocyanins in peach fruits.3.The results of yeast two-hybrid and bimolecular fluorescence complementation experiments show that there is an interaction between PpARF4 and PpMYB10.1;In addition,after heterologous overexpression of PpARF4 in tobacco,the ability of PpMYB10.1 to promote anthocyanin synthesis was reduced.The interaction between PpARF4 and PpMYB10.1 in peach fruits was preliminarily determined to inhibit the activation of PpMYB 10.1,thereby inhibiting anthocyanin synthesis.So,PpARF4 is involved in the regulation of anthocyanin synthesis in peach fruits by auxin and is a transcriptional repressor.