Effects of elevated atmospheric CO2 on trichome densities in soybean (Glycine max) and radish (Raphanus raphanistrum).

Abstract

What had not been examined is the relationship that induction of mechanical defenses and atmospheric CO2 levels may have. It may be predicted that elevated levels of CO2 will cause changes in plants because of the greater amount of carbon available as a resource to the plants. But how will the excessive CO2 be allocated in the plant? Will it be allocated to the defensive system (specifically, trichomes) of the plants? Therefore, I investigated different aspects of induction of trichomes in two species of plants: one capable of symbiosis with nitrogen-fixing bacteria (soybean), and one not (radish) exposed to different levels of CO2. I continued the exploration into the inducibility of trichomes and expanded it to encompass the variable of different levels of CO2. 1) Does elevated atmospheric CO2 affect trichome densities in soybean? 2) Does damage affect trichome densities in soybean? 3) Does elevated CO2 affect induction of trichomes in soybean? 4) Does elevated CO2 affect constitutive trichome densities in radish? 5) Do natural radish populations contain genetic variation for trichome densities under ambient and/or elevated CO2?