Idetification Of Resistance To Root-knot Nematode,Cloning And Expression Analysis Of HcWRKY1 In Kenaf(Hibiscus Cannabinus)

WRKY transcription factor in plants,involved in a variety of biological processes,such as plant defense responses,development and metabolism regulation.In this study,HcWRKYl,a new WRKY genes,was isolated and analyzed from kenaf(Hibiscus cannabinus),identificated its expression and preliminary function.The main results were as follows:1.The results showed that the main species of root-knot nematode in the field were Meloidogyne incognita,Meloidogyne javanica and Meloidogyne arenria.5,19,25 and 71 varieties of 120 tested varieties were of high susceptibility,middle susceptibility,middle resistance and high resistance to these root-knot nematodes,respectively.Further study was carried out in representative 25 varieties using pot culture,7 varities were middle resistance to Meloidogyne incognita,but no highly resistance or immune varieties.2.The HcWRKY1,1126bp in length,was obtained,containing 102bp 5'UTR and 112bp 3'UTR,915bp open reading frame and encoding a polymorphism of 304 amino acids,belongs to group ? a of WRKY transcription factors.3.Bioinformatics analysis indicated that the protein encoded by He WRKY1 was a water-soluble protein,with the molecular formuia was C1443H2325N435O463S13,relative molecular weight was 33.6KDa and pI value was 8.88,containing 42 positive charged residues(Arg+Lys)and 36 negative charged residues(Asp+Glu).4.Quantitative Real-Time PCR(qRT-PCR)analysis indicated that HcWRKYl gene expression could be induced by NaCl,PEG,mechanical damage and low temperature,and has a tissue-specific with the highest expression in the root.5.The pCAMBIA1304-HcWRKY1-GFP expression vector was constructed to study the subcellular localization of HcWRKY1,and the results showed that HcWRKY1 located in the nucleus.The pCAMBIA1301-HcWRKY1 overexpression vector was constructed and transformed Arabidopsis thaliana via Agrobacterium mediated.Genomic DNA of resistant seeding was extracted for PCR identified,and the results showed that HcWRKYl was expressed in Arabidopsis successfully.