Plants defend themselves during attempted invasion of
pathogens via induced and systemic acquired resistance mechanisms. One of the
important active components of plant defense is the production of low molecular
weight antimicrobial compounds called phytoalexins. Sorghum plants produce
phytoalexins of the 3-deoxyanthocyanidins type as a rapid response to Cochliobolus heterostrophus infection. These compounds have structural
similarities with flavan-4-ols; the precursors of the red phlobaphene pigments that
accumulate in the developing kernels of sorghum. Previous studies suggested
that flavan -4-ol might serve as precursors of sorghum 3-deoxyanthocyanidins
phytoalexins. Recent studies from our lab indicated that flavan-4-ol biosynthesis
is under the control of a Myb transcription factor yellow seed1 (y1). We want to extend this work further and test if the
biosynthesis of flavan-4-ol and 3-deoxyanthocyanidins are under a common
regulation of y1. The objective of
this project was to genetically demonstrate if y1 is required for
sorghum phytoalexins by screening .