MAPK5 And MAPK10 Participate In Ripening And Resistance Formation Of Strawberry Fruit

In this experiment,we constructed silence and overexpression vectors to silence and overexpress FaMAPK5 and FaMAPK10 genes in strawberry fruits（Fragaria×ananassa cv.Bebihoppe）,combined with ABA,sucrose,fructose,glucose and other substances in fruits,physiological indicators related to ripening and gene expression,changes of antioxidant enzymes activities,and experiments of injecting gray mold to preliminarily clarify FaMAPK5 and FaMAPK10 genes in strawberry fruits.Function of genes in strawberry fruit ripening and gray mould resistance.The main results are as follows:1.Quantitative PCR was used to analyze the temporal and spatial expression patterns of FaMAPK5 and FaMAPK10 genes.The results showed that FaMAPK5 and FaMAPK10 genes were specifically expressed in the roots,stems,leaves,flowers and fruits of strawberries at different developmental stages.The expression of FaMAPK5in leaves was the highest,and the expression of FaMAPK5 in all tissues of strawberry was relatively low in fruit（full red stage）,while in the early stage of fruit development,the expression of FaMAPK5 was the highest in white ripening stage,and the expression of FaMAPK5 decreased slightly after fruit turned red.The expression of FaMPAK10 gene was the lowest in leaves and the highest in fruit（full red stage）.During fruit development,the expression of FaMPAK10 gene was the highest in white ripening strawberry fruit and the lowest in light green strawberry fruit.2.Silencing and over-expressing vectors of FaMAPK5 and FaMAPK10 genes were constructed to infect strawberry fruits in vitro.The results showed that over-expressing FaMAPK5 and FaMAPK10 genes could significantly increase the contents of ABA,anthocyanin,glucose and total sugar in strawberry fruits,while silencing FaMAPK5 and FaMAPK10 genes could decrease the contents of these indicators.It was also found that silencing FaMAPK5 and FaMAPK10 genes increased sucrose and fructose content.It indicated that FaMAPK5 and FaMAPK10genes were positively regulated with ABA,anthocyanin,glucose and total sugar.3.Experiments on antioxidant activity showed that overexpression of FaMAPK5could effectively increase the activities of antioxidant enzymes SOD,POD and CAT.After silencing FaMAPK5 gene,CAT activity was significantly lower than that of control,but SOD and POD activities were significantly decreased.Significantly increased by 16%and 14.5%.After overexpression of FaMAPK10 gene,the activities of CAT and SOD were significantly increased,while the activity of POD enzyme was significantly decreased.After silencing FaMAPK10,the activity of CAT enzyme was significantly decreased,the activity of POD enzyme was significantly increased,and the activity of SOD was not significantly changed.4.The expression of MAPK is closely related to the content of ABA and H₂O₂ in plants.ABA can promote the expression of FaMAPK10 and FaMAPK5 directly or indirectly through H₂O₂.Overexpression of FaMAPK10 and FaMAPK5 did not increase the H₂O₂ content of strawberry fruit but increased the content of GSH.The silencing of FaMAPK10 and FaMAPK5 also significantly decreased the content of H₂O₂ in strawberry fruit,and silencing FaMAPK10 significantly decreased the content of GSH,but the silencing of FaMAPK5 was significant.Increase the GSH content.This indicates that FaMAPK10 and FaMAPK5 negatively regulate the accumulation of H₂O₂ in strawberry fruit,and FaMAPK10 has a significant effect on the accumulation of GSH,while FaMAPK5 has no significant correlation with the accumulation of GSH.5.It was found that overexpression of FaMAPK10 and FaMAPK5 gene could effectively reduce gray mould infection in strawberry fruit,but overexpression of FaMPAK10 gene did not significantly inhibit the growth of gray mould.