The effects of elevated CO2 on induction of nitrogen-containing defenses: a test with trypsin inhibitor in black mustard (Brassica nigra).

Abstract

Given the inevitability of elevated atmospheric CO2, its potential consequences for constitutive and induced levels of N-containing plant defenses, and the uncertainty about the evolutionary potential of plant defenses in the face of this global environmental change, wild mustard, Brassica nigra (Brassicaceae) will be used to ask the following questions: 1. Does elevated atmospheric CO2 affect the constitutive levels of trypsin inhibitor (N-containing defense) in black mustard? Does this system behave according to the CNB hypothesis, that is, do plants grown in elevated CO2 contain less trypsin inhibitor than plants grown under ambient conditions? 2. Does elevated atmospheric CO2 affect the induction of trypsin inhibitor in black mustard? Does this system behave according to the CNB hypothesis, that is, do plants grown in elevated CO2 display less induction than plants grown under ambient conditions? 3. Is there a trade-off between the N-containing PIs, trypsin inhibitor and chymotrypsin inhibitor, in black mustard? 4. What is the evolutionary potential of this trait under elevated CO2? Do the five maternal families studied exhibit genetic variation in trypsin inhibitor induction under elevated CO2?