Cinnamoyl-CoA reductase 1 (AtCCR1) (AtCCR1)

Cinnamoyl-CoA reductase 1 (AtCCR1) is a key enzyme in the model plant Arabidopsis thaliana that catalyzes the first committed step of the lignin-specific branch of the phenylpropanoid pathway. It is responsible for the NADPH-dependent reduction of hydroxycinnamoyl-CoA esters, such as feruloyl-CoA and sinapoyl-CoA, into their corresponding cinnamaldehydes. AtCCR1 is primarily expressed in tissues undergoing constitutive lignification, such as the xylem of stems and roots, and is essential for maintaining the structural integrity of the plant's vascular system. In the field of biotechnology, AtCCR1 is a major target for genetic manipulation to reduce lignin content, which improves the efficiency of cellulosic biofuel production and the digestibility of animal forage. However, targeting AtCCR1 presents significant challenges, as severe downregulation often leads to lignin-reduction syndromes characterized by dwarfism, collapsed xylem vessels (the irregular xylem or irx phenotype), and reduced biomass. While not a human therapeutic target, it is a critical focus for agricultural and industrial biotechnology aimed at optimizing plant cell wall composition for sustainable energy and materials.

Other names

IRREGULAR XYLEM 4IRX4At1g15950Protein IRREGULAR XYLEM 4

Catalyzes the NADPH-dependent reduction of cinnamoyl-CoA esters (such as feruloyl-CoA and sinapoyl-CoA) to their corresponding cinnamaldehydes, which is the first committed step in the lignin-specific branch of the phenylpropanoid pathway.