Research Progress on Harmful Characteristics and Mechanism of Walnut Late Frost
The occurrence of early spring and late frost damage brought severe challenges to the production of walnuts in China,seriously affecting their growth,development,yield and revenue.In order to clarify the harmful characteristics and influencing mechanisms of late frost on walnuts in China,the influencing factors of the degree of damage caused by late frost on walnuts,as well as the changes in physiological and biochemical indicators and molecular mechanisms in response to low temperature stress were reviewed.It was found that research on physiological changes focused on the three aspects including cell membrane system(relative conductivity),antioxidant system(malondialdehyde,superoxide dismutase,peroxidase and catalase)and osmoregulation substances(soluble sugars,soluble protein and proline),in addition,the expression levels of genes such as JrPAL,JrJAZ,JrGRAS,JrICE1,JrCBF/JrDREB1,JrCOR,JrWRKY,JrDHN,JrGST,and JrPUB were induced by low temperature stress.And prospects were put for future research directions,which provided scientific basis for further exploring the response mechanism of walnuts to late frost damage and adopting effective production measures.