Transcription factors mediating regulation of photosynthesis

Abstract

Photosynthesis by which plants convert carbon dioxide to sugars using the energy of light is fundamental to life as it forms the basis of nearly all food chains. Surprisingly, our knowledge about its transcriptional regulation remains incomplete. Effort for its agricultural optimization have mostly focused on post-translational regulatory processes^1–3 but photosynthesis is regulated at the post-transcriptional⁴ and the transcriptional level⁵. Stacked transcription factor mutations remain photosynthetically active^5,6 and additional transcription factors have been difficult to identify possibly due to redundancy⁶ or lethality. Using a random forest decision tree-based machine learning approach for gene regulatory network calculation⁷ we determined ranked candidate transcription factors and validated five out of five tested transcription factors as controlling photosynthesis in vivo. The detailed analyses of previously published and newly identified transcription factors suggest that photosynthesis is transcriptionally regulated in a partitioned, non-hierarchical, interlooped network.