DROUGHT HYPERSENSITIVE negatively regulates cuticular wax biosynthesis by promoting the degradation of transcription factor ROC4 in rice

Wax covering the outer surface of the shoot (epicuticular wax) is crucial in the ability of the plant to conserve water. Wang et al. identified a drought hypersensitive plant that overexpresses an E3 ubiquitin ligase which they named DROUGHT HYPERSENSITIVE. In these overexpression plants, there was a significant reduction in wax deposition. The authors speculated that DHS might function through targeting a transcription factor involved in wax deposition. They screened several known transcription factors for interaction with DHS and found that ROC4, (which has previously been shown to regulate wax biosynthesis in Arabidopsis, maize and tomato) interacts with DHS in vivo and in vitro. Finally, they showed that ROC4 binds to and regulates the expression of BDG, a gene involved in wax biosynthesis. This signaling pathway offers a new target for engineering drought-tolerance. (Summary by Mary Williams) Plant Cell 10.1105/tpc.17.00823