The Influence of Prior Water Stress and Abscisic Acid Foliar Spraying on Stomatal Responses to CO2, IAA, ABA, and Calcium in Leaves ofSolanum melongena

The influence of a water stress or foliar ABA spraying pretreatment on stomatal responses to water loss, exogenous ABA, IAA, Ca2+, and CO2 were studied using excised leaves of Solanum melongena. Both pretreatments increased stomatal sensitivity of water loss, in the presence and absence of CO2, but decreased stomatal sensitivity to exogenous ABA. CO2 greatly reduced the effect of exogenously applied ABA. IAA decreased leaf diffusion resistance for control and ABA sprayed leaves, but did not influence the LDR of previously water-stressed leaves. CA2+ did not influence LDR of any leaves of any treatments.