Study On The Function Of AcMYBR1 And AcMYB15 In Fruit Ripening And Canker Resistance Of Kiwifruit

Kiwifruit is one of the most successfully domesticated fruits in the last century.It is rich in dietary fiber and vitamin C,rich in nutrition and high economic value.Plant quality and disease resistance are two important characters in production.How to improve the storage performance and shelf life of kiwi fruit during storage and transportation? Previous studies have found that at a proper low temperature,it can delay aging and improve the quality of kiwi fruit to a certain extent.In view of this,this experiment analyzed the functions of AcMYBR1 gene and AcMYB15 gene which were induced by low temperature MYB transcription factors on the basis of the previous stage.The main results are as follows:1.After measuring the physiological indexes of kiwifruit after storage,it was found that with the extension of storage time,the fruit hardness decreased,the soluble solids(SSC)gradually increased,vitamin C increased first and then decreased,and the sugar(glucose,fructose,sucrose)content gradually increased,anthocyanins gradually increase.2.Expression analysis of AcMYBR1 gene and AcMYB15 gene: Expression profiles of AcMYBR1 and AcMYB15 genes at different periods of low temperature and room temperature storage were used by q RT-PCR: at room temperature of 25℃,the expression of AcMYBR1 gene in ’Hongyang’ kiwifruit was basically the same,but at low temperature of 2℃,the expression of AcMYBR1 gene was significantly up-regulated and reached the peak value at 10 d and then down-regulated.The AcMYB15 gene showed low temperature inhibition.Experiments done using q RT-PCR to ’Hongyang’ kiwifruit seed leaves after inoculation canker AcMYBR1 and AcMYB15 gene expression was analyzed: ’Hongyang’kiwifruit somaclone after inoculation of Psa,CL AcMYB15 and AcMYBR1 genes expression trend: the early AcMYBR1 gene and AcMYB15 rapid rise to express,in the later stages of the infection,’Hongyang’ AcMYB15 and AcMYBR1 genes expression and showed a trend of lower expression.However,the expression of the two genes after Psa inoculation was lower than that of the control group,indicating that when Psa infected kiwifruit,the expression of AcMYBR1 and AcMYB15 genes was down-regulated.3.Cloning and Bioinformatics analysis of Actinidia AcMYBR1 gene and AcMYB15 gene:The CDs sequences of AcMYBR1 gene and AcMYB15 gene;the total length of AcMYBR1 gene of Actinidia is 828 BP,encoding 275 amino acids;the total length of AcMYB15 gene of Actinidia is 786 BP,which encodes 261 amino acids,and the corresponding amino acid sequence was analyzed.The protein properties of AcMYBR1 and AcMYB15 genes are not stable,and they are all hydrophilic proteins.Moreover,both genes have highly conserved SANT domains.AcMYBR1 gene contains 48 amino acids(28-76).The first gene of AcMYB15 contains 50 amino acids(13-63)and the other 48 amino acids(66-114).4.AcMYBR1 and AcMYB15 disease resistance identification:The content of kiwifruit leaf canker was determined by dilution plate method and the results were obtained by microscope observation.The results showed that:The content of canker in kiwifruit leaves injected with the mixture of AcMYBR1 gene PBI121 and PSA was 2 times lower than that injected with PSA,while the content of canker in kiwifruit leaves injected with the mixture of AcMYB15 gene P1300 and PSA was 4 times lower than that injected with PSA.The results showed that AcMYBR1 and AcMYB15 were resistant genes.5.Genetic transformation of model plants:The p BI121 and P1300 overexpression vectors were constructed respectively.I transformed the model plants of tomato and Arabidopsis respectively,and detected the DNA extracted from the leaves of tomato plants and Arabidopsis plants on the screening medium by PCR.Three positive plants with overexpression of ’Hongyang’ AcMYBR1 gene and AcMYB15 gene were obtained respectively.In conclusion,it is very important for the storage and preservation of postharvest kiwifruit.AcMYBR1 and AcMYB15 genes are the key genes and play an important role in the research of anti ulcer.It laid a foundation for further analysis of the role of Actinidia AcMYBR1 gene and AcMYB15 gene in postharvest and disease resistance regulation.