Stomatal Aperture
Trees treated with Cambistat may have elevated levels of the hormone
abscisic acid that results from the interruption of the production
of gibberellic acid in the isoprenoid pathway. Abscisic acid plays
a key role in the aperture of the stomata. It is naturally produced
in root tips in response to dry soils. From the roots it is transported
through the xylem into the canopy and eventually the leaves. In
the leaves, abscisic acid signals the guard cells of the stomata
to close. By elevating levels of this hormone with Cambistat stomatal
aperture is more conservative and water status is maintained. Research
with growth regulators demonstrates this effect, as seen in the
chart on the right. |
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