Yu Zhang’s lab focuses on gene transcription in plant chloroplasts, the semi-autonomous organelles primarily responsible for photosynthesis. Chloroplasts harbor a uniquely chimeric complex transcriptional regulatory network comprising components both inherited from their bacterial ancestors and acquired from their endosymbiosis host. We aim to understand how chloroplast RNA polymerase initiates and terminates gene transcription, and how it couples transcription with RNA maturation and protein translation. Moreover, chloroplasts have lost most transcription factors derived from their bacterial ancestor and evolved novel mechanisms to adapt to complex host regulation. We aim to identify these regulatory factors, understand their molecular mechanism, and reveal their physiological roles. Ultimately, we aim to modify the transcriptional regulation network, enhance chloroplast photosynthetic efficiency, and increase crop yields.