Silencing the conserved small nuclear ribonucleoprotein SmD1 target gene alters susceptibility to root-knot nematodes in plants

Abstract

Root-knot nematodes (RKNs) are among the most damaging pests of agricultural crops. Meloidogyne is an extremely polyphagous genus of nematodes that can infect thousands of plant species. A few genes for resistance (R-genes) to RKN suitable for use in crop breeding have been identified, but virulent strains and species of RKN have emerged that render these R-genes ineffective. Secretion of RKN effectors targeting plant functions mediates the reprogramming of root cells into specialized feeding cells, the giant cells, essential for RKN development and reproduction. Conserved targets among plant species define the more relevant strategies for controlling nematode infection. The EFFECTOR18 (EFF18) protein from M. incognita interacts with the spliceosomal small nuclear ribonucleoprotein (snRNP) D1 (SmD1) in Arabidopsis (Arabidopsis thaliana), disrupting its function in alternative splicing regulation and modulating the giant cell transcriptome. We show here that EFF18 is a conserved RKN-specific effector that targets this conserved spliceosomal SmD1 protein in Solanaceae. This interaction modulates alternative splicing events produced by tomato (Solanum lycopersicum) in response to M. incognita infection. The alteration of SmD1 expression by virus-induced gene silencing (VIGS) in Solanaceae affects giant cell formation and nematode development. Thus, our work defines a promising conserved SmD1 target gene to develop broad resistance for the control of Meloidogyne spp. in plants.

miR167-ARF8, an auxin-responsive module involved in the formation of root-knot nematode-induced galls in tomato

“…PolyA-RNA libraries from St Pierre tomato were generated from 500 ng of total RNA using Truseq Stranded mRNA kit (Illumina). Libraries were sequenced on a NextSeq 500 platform (Illumina) with 2□×□75bp paired-end chemistry as described in (Mejias et al ., 2022). RNA-seq data are available at SRA database accession number #PRJNA799360.…”

The root-knot nematode effector Mi2G02 hijacks a host plant trihelix transcription factor to promote nematode parasitism

“…Mi16D10 may be one such effector, as it has been shown to interact with plant SCARECROW-like TFs known to regulate root development ( Huang et al., 2006 ). Another example is provided by MiEFF18, an effector that interacts with the spliceosomal protein SmD1 to trigger alternative splicing events during pre-mRNA maturation in galls, thereby increasing the diversity of host transcripts ( Mejias et al., 2021 , 2022 ).…”

Enzyme-Responsive Lignin Nanocarriers for Triggered Delivery of Abamectin to Control Plant Root-Knot Nematodes (Meloidogyne incognita)

“…Tomato (Solanum Lycopersicon L.) is one of the most popular edible crops in the world, with the global tomato production reaching 43.8 million tons in 2020. − However, pests, soil-borne fungal pathogens, and bacterial wilt can have a momentous impact on crop failure and economic damage . Among them, root-knot nematodes (RKNs) (Meloidogyne incognita) are considered to be the most detrimental . The infective second-stage juveniles (J2s) of the RKN arrive at the root and destroy lignin to enter the root by secreting cell wall decomposition enzymes and cellulases. , Cell wall decomposition enzymes include pectinase, cellulase, hemicellulase, and so forth.…”