光响应基因BcCfaS通过脂质代谢调控灰葡萄孢菌的光形态建成及致病力

Light is a fundamental environmental factor for living organisms on earth—not only as a primary energy source but also as an informational signal.In fungi,light can be used as an indicator for both time and space to control important physiological and morphological responses.Botrytis cinerea(B.cinerea)is a devastating phytopathogenic fungus that exploits light cues to optimize virulence and the balance between conidiation and sclerotia development,thereby improving its dispersal and survival in ecosystems.However,the components and mechanisms underlying these processes remain obscure.Here,we identify a novel light-signaling component in B.cinerea,BcCfaS,which encodes a putative cyclopropane fatty-acyl-phospholipid synthase.BcCfaS is strongly induced by light at the transcriptional level and plays a crucial role in regulating photomorphogenesis.Deletion of BcCfaS results in reduced vegetative growth,altered colony morphology,impaired sclerotial development,and enhanced conidiation in a lightdependent manner.Moreover,the mutant exhibits serious defects in stress response and virulence on the host.Based on a lipidomics analysis,a number of previously unknown fungal lipids and many BcCfaS-regulated lipids are identified in B.cinerea,including several novel phospholipids and fatty acids.Importantly,we find that BcCfaS controls conidiation and sclerotial development by positively regulating methyl jasmonate(MeJA)synthesis to activate the transcription of light-signaling components,revealing for the first time the metabolic base of photomorphogenesis in fungi.Thus,we propose that BcCfaS serves as an integration node for light and lipid metabolism,thereby providing a regulatory mechanism by which fungi adapt their development to a changing light environment.These new findings provide an important target for antifungal design to prevent and control fungal disease.

Alginate oligosaccharide improves resistance to postharvest decay and quality in kiwifruit(Actinidia deliciosa cv. Bruno)

Kiwifruit is an extremely perishable fruit;postharvest disease and senescence during storage can reduce the fruit quality,resulting in economic loss.Considerable research effort has focused on identifying safe and cost-effective ways to preserve fresh kiwifruit.To this end,the present study investigated the effects of alginate oligosaccharide(AOS)soaking treatment on postharvest quality and disease in the‘Bruno’variety of kiwifruit.The involved physiological mechanisms were further explored.The results showed that AOS did not inhibit the growth of Botrytis cinerea in vitro,the causal agent of gray mold in kiwifruit,but reduced the incidence of gray mold and diameter of lesions of kiwifruit during storage.Kiwifruit treated with 50 mg·L-1 AOS showed a higher degree of firmness and lower soluble solid content than control fruit treated with distilled water.Moreover,AOS treatment inhibited the activity of polygalacturonase and pectinesterase,while enhancing the activity of polyphenoloxidase,l-phenylalanine ammonia lyase andβ-1,3-glucanase related to pathogen defense,and also improved total antioxidant capacity determined by the DPPH,FRAP,and ABTS methods in kiwifruit.These results indicate that 50 mg·L-1 AOS can confer disease resistance in kiwifruit during storage.

Advances and Strategies for Controlling the Quality and Safety of Postharvest Fruit

Fresh fruits are highly valued by consumers worldwide,owing to their delicious flavors,abundant nutrients,and health-promoting characteristics,and as such,fruits make up an important component of a healthy diet.The postharvest quality and safety of fresh fruit involve complex interactions among the fruit,environmental factors,and postharvest pathogens.Efficient regulation of fruit senescence and pathogen resistance,as well as disease-causing abilities of postharvest pathogens,is critical to understanding the fundamental mechanisms that underlie fruit quality and safety.This paper provides a comprehensive review of recent advances and currently available strategies for maintaining fruit quality and controlling major postharvest pathogens,mainly Botrytis cinerea and Penicillium expansum,which may promote sustainable and environmental-friendly development of the fruit industry.

Molecular basis for optimizing sugar metabolism and transport during fruit development

Sugars are fundamental metabolites synthesized in leaves and further delivered to fruit in fruit crops.They not only provide"sweetness"as fruit quality traits,but also function as signaling molecules to modulate the responses of fruit to environmental stimuli.Therefore,the understanding to the molec-ular basis for sugar metabolism and transport is crucial for improving fruit quality and dissecting responses to abiotic/biotic factors.Here,we provide a review for mol ecular components involved in sugar metabolism and transport,crostalk with hormone signaling and the roles of sugars in responses to abiotic and biotic stresses.Moreover,we also envisage the strategies for optimizing sugar metabolism during fruit quality maintenance.