A AchGLK Gene Improving The Tomato Fruit Quality And The Study On P.expansum LysM Genes

GLK plays an important role in chloroplast development,cellular differentiation,chloroplast development and senescence in plant.A kiwifruit gene Ach17g471351.2(Ach GLK)involved in chloroplast development was obtained.The gene has two different transcription(Ach GLKFand Ach GLK+48).The former is less 48 bp than the latter.The C-terminal of Ach GLK has a highly conserved GCT-box and the C-terminal DNA binding region(DBD)has an AREAEAA consensus sequence.Experimental analysis indicated that Ach GLKFand Ach GLK+48expressed in all examinded tissues of Actinadia chinensis.In addition to hongyang kiwifruit,Ach GLKFand Ach GLK+48were also found in the Actinidia eriantha Benth and the Actinidia deliciosa.Ach GLK+48transgenic tomato shown no significant difference compared with wild type of tomato.In Ach GLKFtransgenic tomato,the color of immature tomato fruit pericarp was dark green.The content of chlorophyll a/b,plastid number and size and stacks of thylakoids increased significantly in Ach GLKFtransgenic tomato.Pericarp of mature Ach GLKFtransgenic tomato was red with dark spots.In the mature pericarp,lycopene,β-carotenoids,total carotenoids,glucose,fructose,sucrose and soluble solids content were significantly improved,which provide a new way for impoving the quality of agricultural products.Metabolomic analysis shown that Ach GLKFoverexpression in tomatoes may partially improve metabolite contents in the choline degradation pathway,glycine betaine biosynthesis,crocetin biosynthesis,cutin biosynthesis and carotenoid cleavage.Effectors play an important role in the interaction between pathogenic microorganisms and hosts.In order to study the biological process and mechanism during the host-organism intraction,the methods of mining P.expansum effector protein were established.Combined with transcriptome analysis,45 reliable core effector gene and 104 important effector genes were obtained.The 45 core genes should be paid more attention to,because these genes could play important roles during the infection of P.expansum on the fruit host.These genes included PEX2 004440,PEX2 101850,PEX2 107240,PEX2 094840,PEX2 009280,PEX2 038230,PEX2 017860,etc.LysM family proteins of pathogens have important biological functions in the interaction with fruit hosts.A total of 19 Pe Lys M family genes were predicted.According to the international cooperation.We knocked out Pe Lys M4-Pe Lys M19.After phenotypic analysis,some important effectors were screened such as PEX2 025087(Pe Lys M12)and PEX2 101830(Pe Lys M15),providing a solid foundation to the research of gene function.We gave more detailed analysis to the gene Pe Lys M15,which encodes pectate lyase.The activity of pectate lyase in the mutant significantly decreased,but the activity of pectin lyase increased.The Pe Lys M15 mutant expanded slowly on the PDA plate,but the expansion rate on the fruits were accelerated.Pe Lys M15 gene effected the elongation of the spore tube and the mutants secreted more NH+4in the liquid medium and during the growth on the apple.NH+4induced more free radicals in the apple,which accelerated the apoptosis of the host cell.The metabolic group analysis shown that the mutation of the gene could lead to the abnormality of the coenzyme pathway related to amino acid metabolism pathway or amino acid metabolism of P.expansum mutant.The study of P.expansum effectors laid a foundation in the fruit postharvest diseases control.