Abstract：Abstract Cellulose binding proteins (CBP) are cell wall-related effectors secreted by plant-parasitic nematodes during parasitism. In this study, a new cellulose binding protein gene Me-cbp-1 (GenBank No: KU350655) was cloned from the root-knot nematode Meloidogyne enterolobii by rapid-amplification of cDNA ends (RACE) based on transcriptome sequencing analysis. The full-length of Me-cbp-1 cDNA was 809 bp, including a 627 bp open reading frame (ORF). The cDNA contained of 43 bp 5'-untranslated region (UTR) and 139 bp of 3'-UTR. The ORF encodes a deduced protein of 208 amino acids with a calculated molecular weight of 22.2 kD and a pI of 4.0. The predicted protein Me-cbp-1 had a putative signal peptide for secretion and a cellulose binding domain. Homology analysis showed that Me-cbp-1 shared 88%~91% identities with cellulose binding proteins from root-knot nematodes M. incogntia, M. javanica and M. arenaria. In situ hybridization analysis showed that the transcript of Me-cbp-1 accumulated exclusively within cells of subventral gland on the J2s of M. enterolobii. To illustrate the importance of Me-cbp-1 in the parasitism of M. enterolobii, gene expression was knocked down using RNAi. Knocking down the expression of Me-cbp-1 in pre-parasitic nematodes significantly reduced the penetration rate of plants by more than 26%. The proportion of nematodes inside the roots relative to those transferred to the roots was 26.8% for the nematodes treated with Me-cbp-1 dsRNA, whereas 36.4% of the nematodes from the gfp dsRNA treatment were found inside the roots 10 days after inoculation. It was indicated that an important role of Me-cbp-1 in the early stages of invasion and migration of J2s in the root. These above results are useful for deeper elucidating the molecular mechanism of parasitism and pathogenesis of M. enterolobii.
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