Location: Wheat, Sorghum and Forage Research
Project Number: 3042-21220-033-01-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 1, 2014
End Date: Jul 31, 2019
Drought regularly threatens sorghum production in the Great Plains region, and this threat is likely to increase in magnitude and severity due to climate change. Lignin is critical component of the cell wall that allows plants to conduct water. However, modifying lignin content and composition are targets improve plants for bioenergy conversion. However, impact of lignin modification in sorghum on drought tolerance has not been investigated. Specific objectives: 1. Examine drought responses in lignin-modified lines of sorghum. 2. Determine the underlying mechanisms that alter drought responses in these materials.
To increase lignin synthesis sorghum, ARS has developed 11 over-expression constructs under control of the 35S promoter, each construct contains a gene encoding different enzyme in monolignol biosynthesis, and one gene encodes a regulatory protein. To impair lignin synthesis sorghum, ARS has developed three brown midrib (bmr) lines, bmr2, 6 and 12, which are impaired 4-coumarate Coenzyme A Ligase (4CL), cinnamyl alcohol dehydrogenase (CAD) and caffeic acid O-methyltransferase (COMT) activities, respectively. These lines will be evaluated for resistance to drought.