Cloning and Expression Characteristics Analysis

Abstract

In order to excavate the related resistant genes in kenaf to root-knot nematodes and explore the molecular mechanism of the interaction between kenaf and root-knot nematodes, based on the obtained gene  NPR1 related to root-knot nematode from kenaf by the transcriptome sequencing, the PCR and RACE technology were used to clone the full length of gene  NPR1  in kenaf, and the gene was named as HcNPR1  in this study. The cDNA of resistant gene HcNPR1  to root-knot nematode has a full length of 2 058 bp, and its gene open reading frame (ORF) is 1 776 bp (Chr: 164-1939), which encodes a protein of 591 amino acids, with an isoelectric point of 6.02 and a molecular weight of 65.321 ku. This gene has 4 conserved domains of NPR1  gene shared by the plants. Real-time RT-PCR results showed that the expression of HcNPR1  gene changed significantly in kenaf after stress of 1 mmol/L jasmonic acid (JA), 1 mmol/L salicylic acid (SA) and 2 mmol/L ethylene (ET). The gene  HcNPR1  expression induced by JA and ET was significantly stronger than that by SA. The expression of HcNPR1  gene reached the maximum when it was treated by SA for 12 hours, and the time for the strongest induction response of JA and ET was 6 hours. The induction trend of the three hormones increased rapidly first and then decreased. Therefore, it is speculated that the HcNPR1  gene in kenaf plays a role on the resistance to root-knot nematodes. The results of this study can provide a theoretical basis for the genetic improvement of kenaf varieties resistant to root-knot nematode and the prevention and control of kenaf root-knot nematode disease in the future.