Biotech Updates

Vessel-Specific Expression of CSE Restores Vascular Integrity in Low Lignin CSE-Loss-of-Function Mutants

July 13, 2016

http://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-016-0551-9

Caffeoyl shikimate esterase (CSE) is the central enzyme to the lignin biosynthetic pathway in Arabidopsis thaliana. The cse-2 loss-of-function mutant exhibits a four-fold increase in cellulose-to-glucose ratio, but also exhibits developmental arrest. To restore normal growth and improve saccharification yield, Ghent University researchers investigated the cause for the yield penalty in the mutants.

The cse-2 mutant exhibited transcriptional repression of genes upstream of CSE, while downstream genes were mainly unaffected, indicating a transcriptional feedback of CSE loss-of-function on monolignol biosynthetic genes. The team also found that the vessel-specific VND7 expression of CSE genes restored the vasculature integrity resulting in improved growth while keeping the lignin content low.

The results reveal how expression of lignin genes is affected upon CSE loss-of-function. The team also found evidence that through a vessel-specific expression approach, vasculature morphology were restored, leading to a higher total glucose release.