STOMATAL BEHAVIOUR FOLLOWING TREATMENT WITH AUXIN‐LIKE SUBSTANCES AND PHENYLMERCURIC ACETATE
1967; Wiley; Volume: 66; Issue: 3 Linguagem: Inglês
10.1111/j.1469-8137.1967.tb06011.x
ISSN1469-8137
Autores Tópico(s)Plant responses to elevated CO2
ResumoS ummary The ‘synthetic auxins’2‐naphthoxyacetic acid (NOXA), i‐napththylacetic acid (NAA) and 2,4‐dichlorophenoxyacetic acid (2,4‐D) caused stomatal closure when apphed to detached leaves via their petioles. In the case of NOXA and NAA this closure was readily reversed if the intercellular spaces were flushed with CO 2‐ free air, but the closure due to 2,4‐D was not reversed by such treatment. It is concluded that NOXA and NAA cause stomatal closure by disturbing the CO 2 balance in the leaf (by stimulating respiration or inhibiting photosynthesis) whereas 2,4‐D exerts a more direct effect on the guard cells. Phenylmercuric acetate (PMA) caused stomatal closure on strips of detached epidermis, and this could be prevented by CO 2‐ free air during the first 2 hours of treatment. Subsequently closure did occur in CO 2‐ free air but by this time the toxicity of PMA had apparently led to death of the cells. The relevance of these observations to the idea that chloroplast volume changes participate in the stomatal mechanism is discussed.
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