Stomata closure in darkened environment, at time zero, with air (0.03% CO₂) or CO₂-free airflow through leaf. (Note: A decrease in conductance indicates inactivation of the proton pump.)

Question

Quizplus · Accepted Answer

This experiment supports only Hypothesis II, which suggests that closure of stomata in a darkened environment occurs due to the inability of proton pump complexes to participate in H+ transport in the absence of light energy. This is because there is a decrease in conductance indicating the inactivation of the proton pump in the dark compared to the light. The presence or absence of COS in the airflow does not affect the conclusion because the hypothesis is not related to the presence or absence of this gas.

Stomata Closure in Darkened Environment, at Time Zero, with Air