Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The gibberellins (GAs) are endogenous regulators of plant growth. Experiments are described here that test the hypothesis that GA regulates hypocotyl growth by altering the extent of hypocotyl cell elongation. These experiments use GA-deficient and altered GA-response mutants of Arabidopsis thaliana (L.) Heyhn. It is shown that GA regulates elongation, in both light- and dark-grown hypocotyls, by influencing the rate and final extent of cellular elongation. However, light- and dark-grown hypocotyls exhibit markedly different GA dose-response relationships. The length of dark-grown hypocotyls is relatively unaffected by exogenous GA, whilst light-grown hypocotyl length is significantly increased by exogenous GA. Further analysis suggests that GA control of hypocotyl length is close to saturation in dark-grown hypocotyls, but not in light-grown hypocotyls. The results show that a large range of possible hypocotyl lengths is achieved via dose-dependent GA-regulated alterations in the degree of elongation of individual hypocotyl cells.

Type

Journal article

Journal

Journal of Experimental Botany

Publication Date

01/08/1999

Volume

50

Pages

1351 - 1357