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Medicago truncatula Vapyrin is a novel protein required for arbuscular mycorrhizal symbiosis
Author(s) -
Pumplin Nathan,
Mondo Stephen J.,
Topp Stephanie,
Starker Colby G.,
Gantt J. Stephen,
Harrison Maria J.
Publication year - 2010
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2009.04072.x
Subject(s) - biology , medicago truncatula , microbiology and biotechnology , hypha , arbuscular mycorrhiza , endosymbiosis , symbiosis , appressorium , botany , endomembrane system , cullin , rhizophagus irregularis , gene , arbuscular mycorrhizal , genetics , ubiquitin ligase , bacteria , plastid , chloroplast , ubiquitin , endoplasmic reticulum , golgi apparatus
Summary Arbuscular mycorrhizal (AM) symbiosis is a widespread mutualism formed between vascular plants and fungi of the Glomeromycota. In this endosymbiosis, fungal hyphae enter the roots, growing through epidermal cells to the cortex where they establish differentiated hyphae called arbuscules in the cortical cells. Reprogramming of the plant epidermal and cortical cells occurs to enable intracellular growth of the fungal symbiont; however, the plant genes underlying this process are largely unknown. Here, through the use of RNAi, we demonstrate that the expression of a Medicago truncatula gene named Vapyrin is essential for arbuscule formation, and also for efficient epidermal penetration by AM fungi. Vapyrin is induced transiently in the epidermis coincident with hyphal penetration, and then in the cortex during arbuscule formation. The Vapyrin protein is cytoplasmic, and in cells containing AM fungal hyphae, the protein accumulates in small puncta that move through the cytoplasm. Vapyrin is a novel protein composed of two domains that mediate protein–protein interactions: an N‐terminal VAMP‐associated protein (VAP)/major sperm protein (MSP) domain and a C‐terminal ankyrin‐repeat domain. Putative Vapyrin orthologs exist widely in the plant kingdom, but not in Arabidopsis, or in non‐plant species. The data suggest a role for Vapyrin in cellular remodeling to support the intracellular development of fungal hyphae during AM symbiosis.