Significant effects of RNAi silencing of the venom allergen‐like protein (Mhi‐vap‐1) of the root‐knot nematodeMeloidogyne hispanicain the early events of infection

Abstract

Gene silencing using RNAi is a powerful tool for functional analysis of nematode genes and can provide a new strategy for the management of root‐knot nematodes. The transcript of the venom allergen‐like protein gene (Mhi‐vap‐1) of Meloidogyne hispanica is localized in the subventral oesophageal gland cells of second‐stage juveniles (J2) and the gene is highly transcribed in this developmental nematode stage. The purpose of this study was to assess whether the silencing of the Mhi‐vap‐1 gene could affect nematode attraction to roots, penetration, development and reproduction in tomato plants. The optimum soaking time to generate silencing of this gene was determined by quantitative RT‐PCR analysis of the relative expression of the Mhi‐vap‐1 gene in the J2 incubated with the soaking solution for 24, 32 and 48 h. At 48 h, the relative expression of Mhi‐vap‐1 decreased, which indicates that this period of time is optimum to silence this nematode gene using the RNAi method. Silencing of the Mhi‐vap‐1 gene interfered with the completion of the nematode life cycle and caused a reduction in nematode attraction to roots, penetration and infection of plants. A small difference in the number of females and galls formed was also observed, which caused a small decrease in the nematode reproduction factor. The use of RNAi silencing of the Meloidogyne effector gene Mhi‐vap‐1 showed that this gene is important for the plant–nematode interaction during the early events of infection and could be a target gene for anti‐nematode strategies.

Analyses of the Root-Knot Nematode (Meloidogyne graminicola) Transcriptome during Host Infection Highlight Specific Gene Expression Profiling in Resistant Rice Plants

“…Importantly, VAPs are key players in the modulation of plant immunity. Knocking down the expression of VAP genes can severely affect nematode virulence [ 45 , 56 , 57 , 58 ]. In particular, expression of VAP genes are required for the onset of parasitism at the time of root invasion and migration through host tissues [ 58 , 59 ].…”

The function of plant PR1 and other members of the CAP protein superfamily in plant–pathogen interactions

“…These CAP proteins play a significant role in aggressiveness of nematodes, as illustrated by MhiVAP1, produced by the important root-knot nematode Meloidogyne hispanica. RNA interference-mediated silencing of MhiVAP1 greatly interferes with the completion of the nematode life cycle and attenuates its attraction to roots, penetration, and colonization of tomato plants, indicating its importance during early stages of infection (Duarte et al, 2017). et al, 2012).…”

Secreted venom allergen-like proteins of helminths: Conserved modulators of host responses in animals and plants

“…A knockdown of stylet-secreted cell wall-degrading enzymes by RNA interference in infective juvenile nematodes can halt host invasion [ 55 ]. Similarly, a knockdown of VAL expression in migratory plant-parasitic nematodes can also reduce their ability to migrate inside host plants and successfully establish a permanent feeding site [ 50 , 56 , 57 ]. These findings suggest that stylet-secreted VALs are important for modulating host responses, particularly during the migration of the nematodes through host tissues and the early stages of an infection.…”