Control of Gibberellin Levels and Gene Expression during De-Etiolation in Pea
Year: 2002
Type: article
Abstract: Gibberellin A(1) (GA(1)) levels drop significantly in wild-type pea (Pisum sativum) plants within 4 h of exposure to red, blue, or far-red light. This response is controlled by phytochrome A (phyA) (and not phyB) and a blue light receptor. GA(8) levels are increased in response to 4 h of red light, whereas the levels of GA(19), GA(20), and GA(29) do not vary substantially. Red light appears to control GA(1) levels by down-regulating the expression of Mendel's LE (PsGA3ox1) gene that controls the conversion of GA(20) to GA(1), and by up-regulating PsGA2ox2, which codes for a GA 2-oxidase that converts GA(1) to GA(8). This occurs within 0.5 to 1 h of exposure to red light. Similar responses occur in blue light. The major GA 20-oxidase gene expressed in shoots, PsGA20ox1, does not show substantial light regulation, but does show up-regulation after 4 h of red light, probably as a result of feedback regulation. Expression of PsGA3ox1 shows a similar feedback response, whereas PsGA2ox2 shows a feed-forward response. These results add to our understanding of how light reduces shoot elongation during de-etiolation.
Source: PLANT PHYSIOLOGY
DOI: 10.1104/pp.010607
Authors: James B. Reid, Natasha A. Botwright, Jennifer J. Smith, Damian P. O'Neill, L. Huub J. Kerckhoffs
Institution: University of Tasmania
Language: English
Topic: Light effects on plants
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2153558895