Molecular Characterization and Virus-Induced Gene Silencing of a Collagen Gene, Me-col-1, in Root-Knot Nematode Meloidogyne enterolobii

Meloidogyne enterolobii, a highly pathogenic root-knot nematode species, causes serious damage to agricultural production worldwide. Collagen is an important part of the nematode epidermis, which is crucial for nematode shape maintenance, motility, and reproduction. In this study, we report that a novel collagen gene, Me-col-1, from the highly pathogenic root-knot nematode species Meloidogyne enterolobi was required for the egg formation of this pathogen. Me-col-1 encodes a protein with the size of 35 kDa, which is closely related to collagen found in other nematodes. Real-time PCR assays showed that the expression of Me-col-1 was highest in eggs and lowest in pre-parasitic second-stage juveniles (preJ2). Interestingly, knockdown of Me-col-1 did not compromise the survival rate of preJ2 but significantly reduced the egg production and consequentially caused 35.79% lower multiplication rate (Pf/Pi) compared with control. Our study provides valuable information for better understanding the function of collagen genes in the nematode life cycle, which can be used in the development of effective approaches for nematode control.