Express Analysis Of MiPDCD6,LeMYB330 And Cloning LeCyt-C Involved In The Precess Of Root-knot Nematode(Meloidogyne Incognita) To Suppress Plant Immunity In Tomato(Lycopersicon Esculentum)

Root-knot nematode(RKN),a typical plant parasite nematode,has caused serious economic losses to agricultural production.The second-stage juveniles of RKN inject esophageal proteins into the host cells of the root through its stylet,inducing changes in the structure and function of the host cells,forming giant cells and thereby producing root knots.Previous research results showed that MiPDCD6 interacts with LeMYB330(Myb-related protein 330-like)in the host giant cells.In the present study,molecular mechanism of MiPDCD6 secreted by RKN(M.incognita)to suppress plant immunity in tomato(Lycopersicon esculentum)was firstly studied by vitro RNAi,overexpression,and qRT-PCR analysis.The research results will lay a good foundation to reveal the signal transduction network of root-knot nematode and host plant interactions and to prevent the root-knot nematode from finding new drug targets as well as to breed anti-root-knot nematode plant.In this paper,the innovative results are as follows:1.The MiPDCD6 over-expression tomato plants were firstly successfully constructed by agrobacterium-mediated genetic transformation method,and then the transgenic plants were inoculated with RKN.The inoculation results showed that the number of root-knots was statistically significantly increased by 44.7% compared with the control group.These results further indicate that Mi PDCD6 of RKN plays an important role in the suppression of tomato immunity by RKN.2.The Le Cyt-C gene of tomato was firstly cloned by homologous gene cloning method.The full-length cDNA of this gene is 388 bp and encodes 122 amino acids.The analysis using the ProtParam tool shows that it is a stable hydrophilic protein.SignaIP-4.1speculates that the protein encoded by the LeCyt-C gene has not a signal peptide,indicating that the protein is a non-secretory protein and is not transferred into tomato after synthesisin the cytoplasm.LeCyt-C protein function prediction results show that the main function of the protein is translation,and there is also a certain possibility involved in regulation,replication and transcription,intermediate metabolism,fatty acid metabolism,energy metabolism.The tomato LeCyt-C protein contains a Cytochrom-C superfamily conserved domain.3.The relative expression levels of MiPDCD6,LeMYB330 and LeCyt-C genes were analyzed by qRT-PCR.The results showed that MiPDCD6 was detected in the overexpressed plants before inoculation,but not in the wild type.The expression level of LeMYB330 and LeCyt-C gene not statistically increased compared with the wild type The expression level of MiPDCD6 in the over-expressed plants was statistically significantly higher than that in the wild type by 64.3%.The expression level of LeMYB330 was statistically significantly decreased by 63.1% compared with the wild type,and the expression level of LeCyt-C was not statistically increased compared with the wild type.The above results indicate that Mi PDCD6 protein and LeMYB330 protein plays an important role in manipulating nematode parasite and host immunity,and LeCyt-C may be involved.