Drought exerts a substantial impact on crop productivity and global food security, a challenge exacerbated by the escalating frequency and severity driven by climate change. The excessive application of nitrate-based fertilizers stands as a primary culprit in water pollution. Additionally, the high energy consumption and carbon footprint associated with industrial fertilizer production significantly contribute to global warming. Consequently, it is imperative to fathom how plants react to fluctuations in water and nitrate availability, paving the way for more efficient resource utilization and optimal crop yields.
In response to water scarcity, plants employ a two-fold strategy. Initially, they close their stomata, curtailing carbon dioxide access and subsequently impeding photosynthesis, leading to diminished growth and yield. Simultaneously, plants mobilize mechanisms to augment water by modifying root hydraulic conductivity, and in the long run, restructuring their root architecture. This intricate dance involves direct hydraulic communication between roots and leaves, complemented by hormonal signalling, culminating in stomatal closure, a protective measure against detrimental desiccation. However, much remains uncharted regarding the intricate interplay of these diverse signals that ultimately fine-tunes leaf gas exchange. Efforts to enhance water and nitrogen use efficiency have identified them as pivotal traits in mitigating resource consumption in plants. Consequently, substantial endeavours have been directed towards uncovering the physiological and genetic factors associated with these traits.
Chloride, once regarded as detrimental to agriculture, has emerged as a macronutrient due to its pivotal roles in water regulation and photosynthetic processes. Despite its non-metabolic nature, chloride shares analogous charge balance and turgor regulation properties, as well as transport mechanisms with nitrate within plants. This suggests that prioritizing chloride over nitrate for osmotic and charge-balancing functions may curtail nitrate accumulation in leaves, thereby enhancing Nitrogen Use Efficiency. Therefore, chloride nutrition presents itself as a potential tool for manipulating both Nitrogen and Water Use Efficiency in plants, thus reducing the overall dependence on water and nitrate in agricultural practices.
The project advocates for a distinctive integration of methodologies, ranging from molecular to ecophysiological, in model crops. Its core objective is to advance our foundational understanding of how chloride influences the outcomes of water and nitrate management on various facets of plant development, including photosynthesis, turgor maintenance, yield, and drought resilience. The primary goals encompass uncovering: i) the pivotal role of chloride homeostasis in plant development, ii) its significance in enhancing water and nitrogen use efficiency, and iii) the practical application of this knowledge in crop management. These pursuits will be underpinned by cutting-edge, process-based models encompassing photosynthesis, stomatal conductance, and root hydraulic architecture, bolstered by state-of-the-art phenotyping techniques.
