Ian Major

  • Jan 16, 2018

Date & Location: January 16, 2018, at 12p; Room 168 Plant Biology Building

Subject: Metabolic re-programming during the growth to defense transition

Abstract: Plants resist pests and pathogens with inducible defense programs that typically involve the production of specialized metabolites but are often associated with penalties to growth and development. However, while progress has been made in understanding growth-to-defense transitions in terms of regulatory signaling networks, much remains to be determined about how metabolic re-programming influences growth.

We are investigating the metabolic consequences of chronically elevated defenses in mutants of jasmonate signaling, which regulates a major branch of plant immunity. These plants are highly resistant to insect herbivores, but have dramatic growth penalties, including reduced growth of vegetative tissues, delayed development and compromised seed reproduction. Visualization of metabolic pathways from global protein and transcript profiles suggests that carbon is diverted to defense compounds, for example, the reconfiguration of amino acid metabolism to produce glucosinolate defenses. This strong defense sink is also linked to increased respiration and signs of carbon starvation. We suggest that plants actively readjust growth during growth-to-defense transitions to balance the allocation of resources to defense and avoid the detrimental effects of carbon limitation.

Ian Major is a postdoctoral associate in the lab of Gregg Howe.