Project title: Decrypting chloroplast signalling networks in C4 photosynthesis at cell type-resolution

Amount and duration: $427,623.00; 2022-2025

Awarded to - Kai Chan

Project Summary
This project aims to fill a critical knowledge gap in how photosynthesis, chloroplast signals, metabolism and cell specialisation are coordinated for stress acclimation in plants. It aims to dissect the complex interactions between a) cellular distress signals produced by chloroplasts with b) reactive radicals and c) plant metabolism during heat stress. It expects to provide the first insights into chloroplast signalling critical for heat-tolerant C4 photosynthesis which is active in two specialised leaf cell types in cereals such as maize and sorghum. Expected outcomes include an unprecedented cell-level resolution map of chloroplast signalling, which will benefit the engineering of improved photosynthesis into crops.

National Interest Test Statement
Heat stress decreases crop productivity by up to 80% in important broad-acre crops such as wheat and canola, costing Australian agriculture $1.1 billion annually. Between 20-36% of the heat-induced yield loss is due to impaired photosynthesis. With conditions in Australia forecast to become hotter and drier during the growing season of these crops, this project is timely and strategic. This project will provide critical insights into the regulatory molecular framework of heat-tolerant photosynthesis currently only found in a minority of land plants such as sorghum and sugarcane, which are themselves important Australian crops. Results from this project will facilitate the fine-tuning and engineering of this specialised heat-tolerant photosynthetic mechanism into major cereals including wheat and rice. With a 5% increase in photosynthetic efficiency projected to enable yield rescue worth $500 million annually, this research contributes to safeguarding the viability of Australian agriculture and food security against environmental challenges.