Three Xanthomonas Cell Wall Degrading Enzymes and Sorghum Brown midrib12 Contribute to Virulence and Resistance in the Bacterial Leaf Streak Pathosystem

• DOI: 10.1094/mpmi-05-24-0051-r
• Publication Date: 2025-02-10T18:12:06Z
• Authors: Qi Wang; Kira M. Veley; Joshua M. B. Johnson; Josh Sumner; Gijs van Erven; Mirjam A. Kabel; Singha Dhungana; Jeffrey Berry; Adam Boyher; David M. Braun; Wilfred Vermerris; Rebecca S. Bart
• Keywords: Monolignol; Pathosystem

With an increasing demand for renewable fuels, bioenergy crops are being developed with high sugar content and altered cell walls to improve processing efficiency. These traits may have unintended consequences plant disease resistance. Xanthomonas vasicola pv. holcicola (Xvh), the causal agent of sorghum bacterial leaf streak, is a wide-spread pathogen. Here, we show that Xvh expresses several wall degrading enzymes (CWDEs) during infection, these required full virulence. In tolerant sorghum, infection results in induction key enzyme monolignol biosynthesis, Brown midrib 12 (Bmr12), but this did not affect lignin nor composition. Mutation Bmr12 rendered genotype susceptible. encodes caffeic acid O-methyltransferase (COMT), generates sinapaldehyde as its major product. Growth inhibition presence was observed vitro. We conclude mutations alter components can reduce resistance CWDEs contribute Given enhanced bioprocessing characteristics bmr12 provide cautionary tale current future efforts aimed at developing dedicated crops.