Effects Of Heat Treatment On Related Enzymes And Their Gene Expression In Energy Level And Softening Process Of Apples

Apple(Malus domestica Borkh)is belong to Rosaceae family and can prevent cancer because of riching in vitamins and minerals and other nutrients.Apple cultivation in China has a long history and wide varieties.What’s more,China is the world’s largest producer and consumer of apple.Apple has high storability,but still is restricted by the postharvest rapidly maturing and breathing jump and so on,which lead to the energy loss and quality decline causing economic losses.Therefore,apple fruit mature and fresh-keeping is still the important topic.This study provided the theory basis on senescence technology from the energy change,softening process and molecular level through regulating the energy level,softening process and gene expression of PG and NADP-ME after heat treatment in’Golden Delicious’ fruit.The main findings of this study are as follows:1.The experiment studied the effect of heat treatment on the fruit quality,energy level,activity and gene expression of NADP-ME in ’Golden Delicious’.These results showed that heat treatment can inhibit the decline of malate acid,restrain the gene expression of MdcyME1~MdcyME3 and keep the energy level and promote the degradation of NADPH,accelerate the degradation of SDH.What’s more,there were no obvious influence on content of pyruvic acid and the activity of NADP-ME between HA and CK.These results demonstrated that heat treatment can affect the ripening and senescence process of’Golden Delicious’ fruit and prolong the storage period through keep the energy level in the late fruit storage.2.The experiment studied the effect of heat treatment on the fruit quality,softening process,activity and gene expression of PG in ’Golden Delicious’.These results showed that heat treatment can significantly inhibit the decline of hardness,starch content,reduction of sugar and decrease the expression of MdPG1 gene and reduce superoxide anion release peak,increase the activity of PG and the expression of MdPG2 and MdPG3.What’s more,there were no obvious influence on content of MDA and TSS between HA and CK.These results demonstrated that heat treatment can delay fruit softening process and keep fruit quality,but it did not affect fruit softening by PG activity.