The timing of low R:FR exposure profoundly affects Arabidopsis branching responses.
The ratio of Red to Far Red light (R:FR) is sensed by phytochromes, including phytochrome B, and serves as a signal of potential competition. Low R:FR represses Arabidopsis thaliana branching by promoting the accumulation of abscisic acid in the young buds and by enhancing auxin signaling in the main shoot. While overall plant level branching is reduced by low R:FR, the growth of the uppermost branches tends to be promoted while the lower buds are suppressed. Buds at intermediate positions can show either growth promotion or growth suppression by low R:FR if they become exposed to low R:FR late or early, respectively. This pattern suggests that developmental stage specific programming occurs to modify the response of specific buds to branching regulators including auxin and ABA.
Department of Soil and Crop Sciences; Texas A&M University and Texas A&M AgriLife Research; College Station, TX USA; Faculty of Molecular and Environmental Plant Sciences; Texas A&M University; College Station, TX USA.
Srirama Krishna
SK
Reddy
Department of Soil and Crop Sciences; Texas A&M University and Texas A&M AgriLife Research; College Station, TX USA; Faculty of Molecular and Environmental Plant Sciences; Texas A&M University; College Station, TX USA.
Srinidhi V
SV
Holalu
IFEVA-Facultad de Agronomía; Universidad de Buenos Aires; Consejo Nacional de Investigaciones Científicas y Técnicas; Buenos Aires, Argentina; Fundación Instituto Leloir; Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET; Buenos Aires, Argentina.
Jorge J
JJ
Casal
Department of Soil and Crop Sciences; Texas A&M University and Texas A&M AgriLife Research; College Station, TX USA; Faculty of Molecular and Environmental Plant Sciences; Texas A&M University; College Station, TX USA.
Scott A
SA
Finlayson
D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D007210:Indoleacetic Acids / Q000378:metabolism; D008027:Light; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*
D007210:Indoleacetic Acids; D000040:Abscisic Acid
Arabidopsis; Red light:Far Red light; abscisic acid; auxin; branching; bud; phytochrome