Abscisic Acid Involved In Salicylic Acid Induced Cold Resistance Of Plum Fruit

The plum fruit is a cold-sensitive fruit,which can cause cold damage at uncomfortable low temperature,which reduces the storage quality of fruits and vegetables,which limits the application of low temperature technology.In recent years,the use of small molecular signal substances to enhance the cold resistance of fruits has the advantages of convenient operation,green safety,low cost,stable effect and so on.In this study,the black amber plum fruit was used as the material Through the study of salicylic acid(SA)and abscisic acid(ABA)immersion treatment of plum fruit,the chilling injury index and incidence of chilling injury,total phenol and ascorbic acid content,superoxide Anion generation rate,malondialdehyde content,H2O2 content,peroxidase(POD),polyphenol oxidase(PPO),superoxide dismutase(SOD),catalase(CAT),ascorbate peroxidase(APX)activity,endogenous hormones(SA,ABA)content and other indicators,to explore its role in combating coldness,to determine whether ABA participates in the SA mechanism of improving the cold resistance of plum fruits,and whether H2O2 or cyanide-resistant respiratory pathways Participate in the process of SA and ABA regulating the low temperature tolerance of postharvest plum fruits.1.In order to study the role of SA in improving the cold resistance of plum fruits.They were treated with SA,47.0 ?mol/L ABA,5.0 mmol/L Na2WoO4,1.0 mmol/L SA combined with 5.0 mmol/LNa2WoO4,and distilled water for 30 min.The above indicators are measured.The results showed that the SA and ABA treatments delayed the occurrence of fruit cold injury,improved their active oxygen metabolism scavenging capacity,antioxidant enzymes and active oxygen metabolism scavenging enzyme activity,and promoted the synthesis of endogenous hormones.Na2WoO4,SA combined with Na2WoO4 treatment group improved the ability of cold resistance and endogenous hormone content are lower than the control group.It shows that SA and ABA can delay the chilling injury of plum fruits,improve their cold resistance and active oxygen metabolism,and SA may have a separate mechanism of action on ABA.Na2WoO4 significantly inhibited the cold resistance of plum fruits,and this effect was not affected by SA,indicating that SA increased the cold resistance of plum fruits dependent on ABA.2.To investigate whether H2O2 is involved in the process of SA and ABA regulating the low temperature tolerance of postharvest plum fruits.Use 1.0mmol/L SA combined with 50.0 ?mol/L DPI,47.0 ?mol/L ABA combined with 50.0 ?mol/L DPI,5.0 mmol/L Na2WoO4 combined,12.5 ?mol/L H2O2,and distilled water for the control group for 30 min.The above indicators are measured.The results show that the SA and ABA treatment results are consistent with the above results,H2O2 can effectively improve the fruit cold resistance.However,SA combined with DPI,ABA combined with DPI,Na2WoO4 combined with H2O2 had an inhibitory effect on fruit cold resistance.It shows that SA and ABA increase the cold resistance of plum fruits,which are dependent on H2O2,the second messenger.The results of Na2WoO4 combined with H2O2 treatment group showed that the inhibition of ABA synthesis by exogenous H2O2 could not promote the second messenger to transmit cold resistance signal.The effect of blocking low temperature tolerance caused by ABA synthesis cannot be recovered by exogenous H2O2,which is not the only key factor in the ABA cold-resistant signal network.3.To study whether cyanide-resistant respiration is involved in the process of SA and ABA regulating the low temperature tolerance of postharvest plum fruits.1.0 mmol/L SA,47.0 ?mol/L ABA,1.0 mmol/L SA combined with 4.0 mmol/L SHAM,47.0 ?mol/L ABA combined with 4.0mmol/L SHAM,5.0 mmol/L Na2WoO4 combined with 5.0 mmol/L pyruvate 3.Distilled water is soaked in the control group for 30 minutes.The above indicators are measured.The results showed that SA combined with SHAM had a certain inhibitory effect on fruit cold resistance.Resistant to cyanide respiration participates in the cold signal network of postharvest fruits induced by SA and ABA,but the experimental results show that the effect of salicylic acid signal is more dependent on the cyanide respiration pathway than ABA signal.The results of ABA's treatment of the above indicators were better than those of ABA combined with SHAM,and partly better than Na2WoO4 combined with pyruvate treatment group,indicating that the anti-cold effect of ABA partially depends on anti-cyanide breathing,but it is not a completely limiting factor,and the ABA-induced increase in anti-cold ability There may be other limiting factors besides anti-cyanide breathing.