Uncovering ion transporters important for photosynthetic function

The overall objective is to identify chloroplast ion transporters involved in the regulation of photosynthesis in plants and microalgae.

Research on this topic is important because photosynthetic function is tightly coupled with growth, and we need to understand how photosynthetic components are integrated to operate in a dynamic environment.

Ions (H+, K+, Cl−, Pi−, Mg2+, Ca2+) regulate photosynthesis since the involved protein machinery has strict requirements for pH and ion balance.

An increasing number of genes involved in chloroplast ion transport has been unravelled in plants, and only a few homologous algal genes have been studied thus far.

In the proposed work we aim: a) to identify Mg2+ transporters regulating photosynthetic efficiency in plants; b) to determine how expression of K+ and Cl− transporter genes regulate plant acclimation to fluctuating light; c) to identify the algal genes involved in chloroplast Cl−, Pi−, K+ and Mg2+ fluxes.

We will use Arabidopsis thaliana and Chlamydomonas reinhardtii as model organisms to study the intracellular location, gene expression, heterologous expression and the photosynthetic phenotype of loss-of-function mutants using chlorophyll fluorescence, electrochromic shift and state-of-the-art electron microscopy.

With such knowledge, we hope to achieve an understanding of how to use ion transporters to improve the energy efficiency of photosynthesis in engineered crop plants and microalgae.