EAPSI: Working to Increase Agricultural Productivity through Agrobacterium-Mediated Transformation in A. Thaliana

Wei Wei, Corvallis OR

Investigators

Abstract

Understanding microbe-plant interactions is crucial to combating agriculturally important plant diseases and improving plant production. Agrobacterium species cause crown gall disease on over 300 plant genera, including many economically important crops. Current control methods for crown gall disease are not very effective, resulting in up to 80% infection and loss in nursery plants. Alternatively, Agrobacterium-mediated transformation is a powerful tool for creating transgenic plants with increased agricultural productivity. But many crops are recalcitrant to transformation. This award supports research that will employ novel methods developed by Professor Sanjay Swarup?s lab at the National University of Singapore (NUS) to look at the community composition of the rhizosphere microbiomes of transgenic and untreated A. thaliana using 16S rRNA metagenomic analysis. Understanding how an Agrobacterium virulence protein manipulates plant response to increase infection can help improve prevention and control strategies for crown gall disease, as well as create better plant transformation technologies for making useful transgenic crops. Bacterial and plant metabolites are abundant in the rhizosphere environment and modulate plant-microbe interactions1. I propose to investigate the changes in root exudate metabolites of transgenic Arabidopsis thaliana expressing an Agrobacterium rhizogenes effector protein, GALLS-CT, from a betaestradiol inducible promoter2, and assay if expression of this protein alters the plant rhizosphere microbiome. The GALLS-CT protein is transferred from Agrobacterium into the plant3 and alters host defense gene expression to enhance infection (unpublished data). I will employ novel methods developed by Professor Sanjay Swarup?s lab at the National University of Singapore (NUS) to look at the community composition of the rhizosphere microbiomes of transgenic and untreated A. thaliana using 16S rRNA metagenomic analysis. The goal is to observe changes in the microbial community that might be caused by GALLS-CT expression. I will also collect root exudates from induced GALL-CT expressing plants and untreated plants and perform metabolomics analysis using ultra high-pressure liquid chromatography-mass spectrometry (UHPLC-MS) to look for differences in metabolite profiles that might be caused by GALLS-CT. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the National Research Foundation of Singapore.