Study On The Mechanism Of LED White Light Inhibiting Of Ethylene Synthesis During Ripening Of Apple Fruit

The regulation of fruit ripening has always been a hot research topic,mainly because ripening is an indispensable part of the fruit life cycle,which affects the quality and storage of the fruit after harvest.The fruit ripening process is mainly regulated by ethylene synthesis and signal transduction pathways,but it is also affected by a variety of external environmental factors,such as light and temperature,but the molecular mechanism of light affecting fruit ripening needs further research.In this study,using apple fruit as the test material,the molecular mechanism of LED white light inhibiting ethylene synthesis during apple fruit ripening was studied.The results are as follows:1.Treat the'Golden Delicious'apple fruit with 8 kinds of light,LED white,red,orange,yellow,green,blue,blue and purple respectively,and observe the change of ethylene release.The production of LED,among which LED white light suppression effect is the best.2.Treat the'Golden Delicious'apple fruit with LED white light of 5,10,20,40 and 60?mol·m^-2s^-1,respectively,and observe the changes in the amount of ethylene released.Finally,LED white light was screened to have an ideal and economical light quantum flux density of 20?mol·m^-2s^-1 for inhibiting the production of ethylene in apple fruit.3.Treating apple fruits of'Lushuai'and'Gala'with 20?mol·m^-2s^-1 light quantum flux density LED white light,respectively,it was found that the production of ethylene in the fruit was inhibited to varying degrees.Through the measurement of the soluble solids and hardness of the'Golden Delicious'apple fruit,it was found that the LED white light treatment increased the hardness of the fruit,but had no significant effect on the soluble solids content of the fruit.4.Through transcriptome sequencing and screening from the apple genome,the differentially expressed light signal transduction pathway related genes-homologous genes Md HY5-like of HY5 and mature related genes Md ACS1 and Md ERF3.The expression of Md HY5-like was up-regulated,and the expressions of Md ACS1 and Md ERF3 were down-regulated in LED white light-treated apple fruit.5.The yeast one-hybrid test and the EMSA test verified that Md HY5-like can bind to the promoter of Md ACS1.The above results indicate that Md HY5-like can bind to the promoter of Md ACS1,and Md HY5-like may negatively regulate the transcription of Md ACS1.LED white light may directly inhibit the synthesis of ethylene in apple fruit through this process.This study preliminarily clarified the molecular mechanism of LED white light inhibiting apple fruit ethylene synthesis,and provided an important theoretical basis for the study on how to improve apple fruit storage and extend the shelf life of the fruit.