Renuka Kolli

Renuka currently works within the Schreier group.

Renuka ois passionate about cell biology and especially interested in investigating organelle positioning in plant cells, relating to photosynthesis. The most common form of photosynthesis is called C3 as CO2 is initially fixed into a three-carbon compound before being converted into sugars. However, the photosynthetic efficiency of C3 plants is considerably reduced under high temperature and drought stresses.

A more efficient form of photosynthesis – C4 photosynthesis – has evolved over 60 times independently in different plant lineages from ancestral C3 plants, particularly in hot and dry environments. C4 plants include the agronomically important maize, sorghum and sugarcane, which initially fix CO2 is into a four-carbon compound. Typically, the metabolic reactions of the C4 pathway are spatially separated across two cell-types, mesophyll and bundle sheath, which are arranged in a characteristic Kranz leaf anatomy.

The bundle sheath cells of C4 plants display a remarkable polar positioning of chloroplasts and plasmodesmata (microscopic channels which traverse the cell wall and connect neighboring cells) at specific sides of the cells to facilitate metabolite exchange with the neighboring mesophyll cells, which is likely critical for the higher photosynthetic efficiency of the C4 pathway. Renuka aims to identify these polarity determining factors and mechanisms using biochemistry-based approaches in combination with CRISPR gene editing, as part of the ERC CELL4 project.

Identifying the developmental innovations that underpinned the C4 pathway evolution would aid the ongoing global efforts to improve the photosynthetic efficiency and yields of major food crops such as rice and wheat which carry out C3 photosynthesis.