Rice Gene OsNAC5 Contributes to Drought Tolerance Through Lignin Buildup in Roots

Seoul National University scientists reported the boost in the drought tolerance of rice through lignin buildup in the roots. Their findings are reported in Plant Biotechnology Journal.

Drought is one of the most destructive abiotic stresses that impacts crop development and yield. Previous studies have shown a link between lignin production and drought tolerance, but the molecular mechanisms are still to be identified. Thus, the researchers studied the role of rice gene CINNAMOYL-CoA REDUCTASE 10 (OsCCR10). They found that this gene is directly activated by the OsNAC5 transcription factor, which mediates drought tolerance by controlling the buildup of lignin.  The OsCCR10 transcript levels were found to increase in response to abiotic stresses, such as drought, high salinity, and abscisic acid. The transcripts were found to be present in roots at all developmental stages.

Transgenic rice plants overexpressing OsCCR10 exhibited enhanced drought tolerance at the vegetative stages of growth, and with higher photosynthetic efficiency, lower water loss rates, and higher lignin content in roots compared to non-transgenic counterparts. On the other hand, the CRISPR-Cas9-mediated OsCCR10 knock-out mutants showed reduced lignin accumulation in roots and less drought tolerance.

Read the research article in Plant Biotechnology Journal.