Light induced transpiration in a chlorophyll deficient mutant of Hordeum vulgare

Abstract

Abstract A chlorophyll deficient mutant of Hordeum vulgare L. was investigated with respect to its transpiration response to light pulses. Broad band blue light. 380–500 nm, caused a significant transpiration response, while broad band red light did not. The transpiration response to changes in the ambient CO 2 ‐concentration was the same in the chlorophyll deficient mutant as in green plants. The absence of a transpiration response to red light in the mutant was therefore not the result of a defective CO 2 ‐response. It is concluded that the specific blue light response is not mediated via photosynthetic CO 2 ‐fixation. The nature of the blue light response is discussed.