Identification and characterization of plant genes involved in Agrobacterium-mediated plant transformation by virus-induced gene silencing.

Abstract

Genetic transformation of plant cells by Agrobacterium tumefaciens represents a unique case of trans-kingdom sex requiring the involvement of both bacterial virulence proteins and plant-encoded proteins. We have developed in planta and leaf-disk assays in Nicotiana benthamiana for identifying plant genes involved in Agrobacterium-mediated plant transformation using virus-induced gene silencing (VIGS) as a genomics tool. VIGS was used to validate the role of several genes that are either known or speculated to be involved in Agrobacterium-mediated plant transformation. We showed the involvement of a nodulin-like protein and an alpha-expansin protein (alpha-Exp) during Agrobacterium infection. Our data suggest that alpha-Exp is involved during early events of Agrobacterium-mediated transformation but not required for attaching A. tumefaciens. By employing the combination of the VIGS-mediated forward genetics approach and an in planta tumorigenesis assay, we identified 21 ACG (altered crown gall) genes that, when silenced, produced altered crown gall phenotypes upon infection with a tumorigenic strain of A. tumefaciens. One of the plant genes identified from the screening, Histone H3 (H3), was further characterized for its biological role in Agrobacterium-mediated plant transformation. We provide evidence for the role of H3 in transfer DNA integration. The data presented here suggest that the VIGS-based approach to identify and characterize plant genes involved in genetic transformation of plant cells by A. tumefaciens is simple, rapid, and robust and complements other currently used approaches.

• Authors: Ajith Anand, Zarir Vaghchhipawala, Choong-Min Ryu, Li Kang, Keri Wang, Olga del-Pozo, Gregory B Martin, Kirankumar S Mysore
• Journal: Molecular plant-microbe interactions : MPMI (Mol Plant Microbe Interact) Vol. 20 Issue 1 Pg. 41-52 (Jan 2007) ISSN: 0894-0282 [Print] United States
• PMID: 17249421 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Histones
• Membrane Proteins
• Plant Proteins
• expansin protein, plant
• nodulin

Topics

• Agrobacterium tumefaciens (genetics)
• Gene Expression Regulation, Plant
• Gene Silencing
• Genes, Plant (genetics)
• Histones (genetics)
• Membrane Proteins (genetics)
• Plant Leaves (genetics, microbiology)
• Plant Proteins (genetics)
• Plant Tumors (genetics)
• Tobacco (genetics, microbiology)
• Transformation, Genetic