Transcription Factor Controlling Production of Secondary Cell Walls Found in Rice
Rice produces agronomic biomass residues that contain lots of secondary cell
walls (SCW) comprising cellulose, hemicelluloses and lignin. However, the
transcriptional regulation mechanism underlying SCWs synthesis in rice
remains elusive. The team of Yafeng Ye from the Chinese Academy of Sciences
studied a NAC family transcription factor (TF), OsSND2, and its relation to
OsMYB61, a TF known to regulate SCW synthesis.
The team confirmed that OsSND2 directly binds to the promoter of OsMYB61.
The OsSND2 TF was found to be localized in the nucleus and has
transcriptional activation activity. Further analysis also indicated that
OsSND2 was mainly expressed in internodes and panicles.
Using CRISPR-Cas9, the team developed OsSND2-knockout mutants. These mutants
exhibited decreased cellulose content and downregulated expression of SCW
related genes. Meanwhile, overexpression of OsSND2 resulted in rolled
leaves, increased cellulose content, and upregulated expression of SCW
Taken together, these findings suggest that OsSND2 functions as a master
regulator of SCW synthesis. This study can provide groundwork for
manipulating plant biomass production.