Improving the lignins in plant's biomass is vital in enhancing the
biorefinery process due to lignin's ability to increase biomass heating
value and represent a potent source of valuable aromatic chemicals. However,
limited information is available for effective molecular breeding techniques
to improve lignin production in grass species such as rice, which is a model
grass species. Kyoto University scientists explored using CRISPR-Cas9 to
develop lignin-enriched transgenic rice. Their findings are published in The
Plant Journal.

The researchers generated transgenic rice with improved lignin content via
targeted mutagenesis of the transcriptional repressor OsMYB108 using
CRISPR-Cas9 mediated genome editing. The OsMYB108-knockout rice mutants
exhibited enhanced expressions of lignin biosynthetic genes and improved
lignin deposition in culm cell walls. Further analyses showed that the
mutant cell walls had high levels of ?-p-coumaroylated and tricin lignin
units, which are vital components of grass lignins. The analyses also showed
that the relative abundances of major lignin linkage types were modified in
the rice mutants.

[onlinelibrary.wiley.com]