A synthetic C4 shuttle via the β-hydroxyaspartate cycle in C3 plants
Marc‐Sven Roell, Lennart Schada von Borzyskowski, Philipp Westhoff, Anastasija Plett, Nicole Paczia, Peter Claus, Urte Schlueter, Tobias J. Erb, Andreas P.M. Weber
Abstract
Significance Photorespiration is essential for photosynthesis in an oxygen-containing atmosphere. By mass flow, photorespiration is exceeded only by photosynthetic carbon assimilation. Photorespiration, initiated by the oxygenation reaction of Rubisco, is a major constraint on the photosynthetic efficiency of C3 plants and consequently on crop yield. Mitigating the negative effects of photorespiration holds potential for yield increases and contributes to achieving food and energy security for a growing population. This work presents a synthetic bypass to natural photorespiration (i.e., the conversion of photorespiratory glycolate into a C4 compound via a recently discovered microbial glycolate assimilation pathway, the β-hydroxyaspartate cycle [BHAC]). Simultaneous expression of four enzymes of microbial origin in the land plant model Arabidopsis thaliana enables efficient glycolate conversion into BHAC products.