Study On The Regulation Of Grape Fruit Resistance To Two Pathogenic Fungi By Sodium Nitroprusside

The control of postharvest grape disease is one of the key problems restricting the safe storage and transportation of postharvest grape.Botrytis cinerea and Alternaria alternata are pathogenic fungi that cause the main postharvest diseases of grapes.B.cinerea and A.alternata lurk in grape fruits and branches and stalks in the form of spores and mycelium.When the environment is suitable,they germinate and infect fruits,resulting in fruit stalk decay.Grape drop,the final fruit rot,etc.For a long time,people have been trying to find the technology or method to maintain grape freshness and prolong grape postharvest storage.Studies have shown that Nitricoxide（NO）,as a signaling molecule,participates in the physiological and biochemical processes of plants and plays an important role in maintaining the homeostasis of plant cells under stress.In order to screen out the fresh-keeping substances that can prolong the quality of postharpostharst grapes,the regulation of the interaction between grape and pathogenic fungi was studied by applying sodium nitroprusside（exogenous NO donor）as the entry point.To explore the effects of sodium nitroprusside treatment on the growth and development of B.cinerea and A.alternata,and the regulation of grape resistance to the infection of B.cinerea and A.alternata under sodium nitroprusside treatment.Through observation of fruit apparent characters,determination of endogenous NO and related physiological indicators,and detection of related gene expression levels,etc.The effects of sodium nitroprusside treatment on grape fruit resistance to pathogen fungal infection were comprehensively evaluated.The results provided basic data for clarifying the regulation of sodium nitroprusside and its regulation mechanism,and also provided data support for rational use and development of freshness preservative in production.The main results are as follows:Treatment with 10mmol L^-1sodium nitroprusside reduced the growth rate,sporulation and melanin content of B.cinerea and A.alternata.Treatment with 10mmol L^-1sodium nitroprusside delayed the decline of fruit apparent index quality during resistance to infection by pathogen fungi B.cinerea and A.alternata.Enhance antioxidant enzyme activity;Activating phenylpropane metabolic pathway;In addition,the expression of related genes was regulated and the resistance to pathogenic fungi was improved by activating grape immune system.During the infection of B.cinerea and A.alternata,10mmol L^-1sodium nitroprusside could regulate the expression of key genes such as ethylene synthesis pathway and disease course related proteins,and enhance the resistance of plants to pathogens.