Direct Identification of the Meloidogyne incognita Secretome Reveals Proteins with Host Cell Reprogramming Potential

PLoS Pathogens

Zhouxin Shen¹  Patrick Shih¹  Stéphane Bellafiore¹  Steven P. Briggs¹  Marie-Noelle Rosso²  Pierre Abad² 

[1] Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America;INRA, Unité Interactions Plantes-Microorganismes et Santé Végétale, Antibes, France

关键词: Nematode infections;    DNA-binding proteins;    Sequence databases;    Chaperone proteins;    Plant cells;    Parasitic diseases;    Transcription factors;    Database searching;   

DOI  :  10.1371/journal.ppat.1000192

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The root knot nematode, Meloidogyne incognita, is an obligate parasite that causes significant damage to a broad range of host plants. Infection is associated with secretion of proteins surrounded by proliferating cells. Many parasites are known to secrete effectors that interfere with plant innate immunity, enabling infection to occur; they can also release pathogen-associated molecular patterns (PAMPs, e.g., flagellin) that trigger basal immunity through the nematode stylet into the plant cell. This leads to suppression of innate immunity and reprogramming of plant cells to form a feeding structure containing multinucleate giant cells. Effectors have generally been discovered using genetics or bioinformatics, but M. incognita is non-sexual and its genome sequence has not yet been reported. To partially overcome these limitations, we have used mass spectrometry to directly identify 486 proteins secreted by M. incognita. These proteins contain at least segmental sequence identity to those found in our 3 reference databases (published nematode proteins; unpublished M. incognita ESTs; published plant proteins). Several secreted proteins are homologous to plant proteins, which they may mimic, and they contain domains that suggest known effector functions (e.g., regulating the plant cell cycle or growth). Others have regulatory domains that could reprogram cells. Using in situ hybridization we observed that most secreted proteins were produced by the subventral glands, but we found that phasmids also secreted proteins. We annotated the functions of the secreted proteins and classified them according to roles they may play in the development of root knot disease. Our results show that parasite secretomes can be partially characterized without cognate genomic DNA sequence. We observed that the M. incognita secretome overlaps the reported secretome of mammalian parasitic nematodes (e.g., Brugia malayi), suggesting a common parasitic behavior and a possible conservation of function between metazoan parasites of plants and animals.

【 授权许可】

CC BY