PhD Studentship - SWEET Transporters as Regulators of Carbon Allocation and Drought Resilience in Tomato

Research area and project description

Ensuring crop productivity under climate change is a major challenge, with drought posing one of the most severe threats to agricultural yield. While much attention has focused on photosynthesis, drought also disrupts the allocation of carbon from source leaves to reproductive organs, often limiting yield before photosynthesis itself, is strongly affected.

This PhD project will investigate how SWEET (Sugars Will Eventually be Exported Transporters) regulate carbon partitioning in tomatoes under drought conditions. SWEET transporters mediate sucrose efflux and play a central role in phloem loading and unloading, thereby controlling the distribution of sugars between vegetative and reproductive tissues. Their dynamic regulation under stress suggests that they are key determinants of how plants balance growth and survival during water deficit.

The overall aim is to identify SWEET transporters that control carbon allocation to fruits under drought and assess whether targeted manipulation of their expression can sustain yield. The project will combine plant physiology, molecular biology, and functional genomics approaches. Specifically, the project will:

1. quantify drought-induced changes in carbon assimilation, export, and partitioning using physiological, biochemical and metabolic analyses;
2. identify drought-responsive SWEET genes and evaluate natural variation across tomato genotypes;
3. functionally characterise candidate genes using CRISPR/Cas9 genome editing.

By linking molecular mechanisms of sugar transport with whole-plant physiology, this project will generate fundamental insights into source–sink regulation and provide new strategies for improving drought resilience in tomato and other fruit crops.

Qualifications and specific competences

Applicants to the PhD position must have master’s degree (or equivalent) in plant biology, plant physiology, molecular biology, biochemistry, or a related field.

Further requirements: Solid theoretical background in plant physiology and/or molecular biology; Strong analytical and problem-solving skills; Good communication skills in English (written and oral); Ability to work both independently and as part of a collaborative research team.