Ashley Dudey

With the escalating challenges posed by climate change, plants play a crucial role—both in mitigating its effects and in serving as resilient crops capable of feeding a growing population. Photosynthesis, the process by which plants generate both oxygen and energy, remains a central focus in research efforts aimed at producing these ‘hardy’ crops.

Our group adopts a complementary approach. Rather than targeting the protein complexes that constitute the photosynthetic machinery, we investigate the molecular systems responsible for decoding, transcribing, and translating these proteins within the chloroplast.

Intriguingly, chloroplast transcription machinery closely resembles that of bacteria, although it operates in a more complex context. Central to this system are proteins known as sigma factors, which guide the transcriptional machinery to the correct initiation sites on the DNA.

Plants possess several types of sigma factors, each capable of directing the expression of distinct gene sets for various functions. Under environmental stress—such as high light intensity or drought—Sigma Factor 5 becomes particularly important, activating the repair of damaged photosynthetic machinery.

Building on the Webster group’s success in resolving the structure of the plastid-encoded RNA polymerase (PEP), Ashley aims to employ cryogenic electron microscopy (cryo-EM) to uncover the mechanistic details of Sigma Factor 5-mediated transcription initiation. This work may ultimately inform strategies for engineering more robust, stress-tolerant crops.