Research Student Profile: Leon Chen

Project Title: Targeting of proteins to organelles in nodules

Project Overview

Nodules are legume plant root outgrowths which are caused by infection of Rhizobium, a nitrogen-fixing bacteria. My project is focused on the targeting mechanism of proteins to different organelles using soybean as a model plant.

Nitrogen is an essential macro-nutrient for living creatures, due to its requirement in both nucleic and amino acid synthesis. However the vast majority of nitrogen is found as an inert diatomic gas which is an unavailable form for plants. Legumes are able to access this nitrogen source through forming a symbiosis with nitrogen-fixing bacteria called rhizobia which convert this unavailable form to bio-available ammonium. For this study, I am using the relationship between soybean (legume plant) and the rhizobium Bradyrhizobium japonicum as a model to investigate targeting mechanisms of my proteins of interest.

I will focus on two kinds of proteins, 1) Gm ZIP1, a transport protein on the symbiosome membrane, 2) GART and AIRS, two enzymes that catalyse the 3rd and 5th steps in the de novo purine synthesis pathway. I want to figure out that how Gm ZIP1 is targeted to the symbiosome membrane and how GART and AIRS are targeted to organelles such as mitochondria and plastids. To do this I am using Molecular, Cellular, Genetic and Fluorescence Microscopical techniques.

Purine biosysnthesis in nodules of legumes

Purine biosysnthesis in nodules of legumes

The symbiosome is a mutual form between soybean and Rhizobium whose membrane is derived from the plant. This membrane is a nutrient and energy exchange interface between Rhizobia and soybean. The purine synthesis pathway is also a major nitrogen assimilation pathway in legume plants. The research group in my lab is mainly focused on biochemistry, molecular biology and genomics of electron and ion transport processes, and associated pathways of carbon and nitrogen metabolism in plants. Practical applications may arise from the results obtained as new concepts and observations are used to direct the production of new and improved crop plants. So the main outcome of my work is to devote my small power to this big group.


I was born in middle China. My degree is Bachelor of Engineering at the Huazhong Agricultural University which is also located in middle China.

In 2008, I finished my Bachelor’s degree in China, and graduated from Department of Bioengineering, College of Life Science and Technology, Huazhong Agricultural University.

In earlier 2009, I started to study my Master’s degree by research in University of Sydney until now.undertake post-graduate research at the University of Sydney.