Study On Amelioration Of Acetic Acid-mediated Synthesis Of Jasmonic Acid On Postharvest Chilling Injury Of Common Bean

The metabolism of postharvest common bean is active,so that the shelf life of common bean(Phaseolus vulgaris L.)in room temperature is too short to keep its quality in storage.Cryogenic technique was widely used in preservation of post-harvest common beans as a economic way,while chilling injury(CI)often occurs in low temperature.And CI will lead to symptoms such as browning,watery spots,festering,rotting,etc.CI can affect common bean's quality seriously,and result in a decline in the value of its commodities,which leads to a huge economic losses.Through the preliminary experiment,we used 0 m M,25 m M,50 m M,75 m M,100 m M acetic acid to soak fresh common bean,and put it in 4? to stimulate the environment of chilling injury.And the 50 m M acetic acid treatment was the best.Then the biochemical index and associated signaling pathway of the blank treatment(CK)and the 50 m M acetic acid treatment was analyzed.The results are as follows:1.50 m M acetic acid treatment had the best effect on reducing cold injury of common bean.The storage time was 18.50 days,which was 46.05% longer than the 12.67 days of the CK.And 25 m M acetic acid treatment was 19.73% longer than the CK,whose storage time was 15.17 days.However,high concentration acetic acid treatment(75 m M and 100 m M)increased the chilling injury symptom of common bean,and 100 m M acetic acid treatment's storage time decreased 55.26% compared with the CK.2.Compared with the CK,50 m M acetic acid treatment significantly alleviated the chilling injury symptoms of common bean,and the cold injury rate of 20 days was 26.72%lower than that of the control group,and the appearance difference was obvious.3.The relative conductivity and MDA of common bean treated with 50 m M acetic acid were slower than that of CK,and the content of MDA was lower than CK's.The relative conductivity of the treated group was 17.18% lower than that of the CK on the 20 d.What's more,the content of MDA of the treated group was 10.73% lower than CK's during storage.4.50 m M acetic acid could increase the activity of catalase in common bean,and decrease the activity of POD as well as appear the peak ahead of time,which coincided with the low browning degree of common bean treated with acetic acid during storage.5.The content of jasmonic acid in common bean treated with 50 m M acetic acid increased rapidly within 24 h and returned to its original level after 24 h,which proved that acetic acid could stimulate the bio-synthesis of endogenous jasmonic acid in common bean,and it's effective to play a role to a certain extent in resisting the chilling injury.6.The gene expression of a part of enzymes in jasmonic acid synthesis pathway of common bean was up-regulated,indicating that acetic acid could stimulate the synthesis of endogenous jasmonic acid by regulating the gene expression of jasmonate synthetase,which indicated that acetic acid could stimulate the synthesis of endogenous jasmonic acid.Thus,the effect of jasmonic acid mediated by acetic acid can be used to reduce the chilling injury.According to the results above,acetic acid can increase the synthesis of endogenousjasmonatic acid by stimulating the gene expression of jasmonatic acid-associated synthetase,thus regulating the influence of MDA and CAT through jasmonatic acid regulation pathway.All over above,acetic acid makes effect to reduce chilling injury symptoms during low-temperature storage of common beans.