Proteome-Wide Analyses Provide New Insights into the Compatible Interaction of Rice with the Root-Knot Nematode Meloidogyne graminicola.

Chao Xiang,Xiaoping Yang,Houxiang Kang,Wenkun Huang,Wei Li,Maoyan Liu,Shiming Liu,Deliang Peng

doi:10.3390/ijms21165640

Abstract

The root-knot nematode Meloidogyne graminicola is an important pathogen in rice, causing huge yield losses annually worldwide. Details of the interaction between rice and M. graminicola and the resistance genes in rice still remain unclear. In this study, proteome-wide analyses of the compatible interaction of the japonica rice cultivar “Nipponbare” (NPB) with M. graminicola were performed. In total, 6072 proteins were identified in NPB roots with and without infection of M. graminicola by label-free quantitative mass spectrometry. Of these, 513 specifically or significantly differentially expressed proteins were identified to be uniquely caused by nematode infection. Among these unique proteins, 99 proteins were enriched on seven Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. By comparison of protein expression and gene transcription, LOC_Os01g06600 (ACX, a glutaryl-CoA dehydrogenase), LOC_Os09g23560 (CAD, a cinnamyl-alcohol dehydrogenase), LOC_Os03g39850 (GST, a glutathione S-transferase) and LOC_Os11g11960 (RPM1, a disease resistance protein) on the alpha-linolenic acid metabolism, phenylpropanoid biosynthesis, glutathione metabolism and plant–pathogen interaction pathways, respectively, were all associated with disease defense and identified to be significantly down-regulated in the compatible interaction of NPB with nematodes, while the corresponding genes were remarkably up-regulated in the roots of a resistant rice accession “Khao Pahk Maw” with infection of nematodes. These four genes likely played important roles in the compatible interaction of rice with M. graminicola. Conversely, these disease defense-related genes were hypothesized to be likely involved in the resistance of resistant rice lines to this nematode. The proteome-wide analyses provided many new insights into the interaction of rice with M. graminicola.

Highlights

As one of the top ten plant-parasitic nematodes [1], the root-knot nematode (RKN) Meloidogyne graminicola is a tremendous threat to rice (Oryza sativa L.) worldwide
Because the galls started to be obviously visible at 3 dpi [7,8], the root tips were collected at two time-points, while the root parts mainly containing the galls were selected under stereomicroscopy and collected at the other two time-points (3 and 7 dpi)
Three biological replicates were set for each sample; each replicate was measured by label-free quantitative mass spectrometry independently, and their obtained proteome data were analyzed individually

Summary

Introduction

As one of the top ten plant-parasitic nematodes [1], the root-knot nematode (RKN) Meloidogyne graminicola is a tremendous threat to rice (Oryza sativa L.) worldwide. Recent cultivation pattern alterations and climate changes have further aggravated the damaging effect of this nematode [2,3,4]. This nematode mainly infects rice root tips and induces root cells to form giant cells as a nutrition resource with a characteristic symptom of hook-shaped galls on the roots, resulting in deficient growth and severe rice yield losses of up to 87% [5,6]. Planting resistant rice cultivars is an eco-friendly and economical means to prevent and control this pathogen. Analyses of details of the interaction of rice with M. graminicola and identification of the M. graminicola-resistant proteins (genes) are of significance for the management of this nematode

Methods

Results

Conclusion