Interaction of light and hormone signals in germinating seeds.
Seed germination is regulated by several environmental factors, such as moisture, oxygen, temperature, light, and nutrients. Light is a critical regulator of seed germination in small-seeded plants, including Arabidopsis and lettuce. Phytochromes, a class of photoreceptors, play a major role in perceiving light to induce seed germination. Classical physiological studies have long suggested the involvement of gibberellin (GA) and abscisic acid (ABA) in the phytochrome-mediated germination response. Recent studies have demonstrated that phytochromes modulate endogenous levels of GA and ABA, as well as GA responsiveness. Several key components that link the perception of light and the modulation of hormone levels and responsiveness have been identified. Complex regulatory loops between light, GA and ABA signaling pathways have been uncovered.
Seo
Mitsunori
M
RIKEN Plant Science Center, Yokohama, Kanagawa 230-0045, Japan.
Nambara
Eiji
E
Choi
Giltsu
G
Yamaguchi
Shinjiro
S
D000040:Abscisic Acid / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects; D017360:Arabidopsis / Q000502:physiology / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000502:physiology / Q000528:radiation effects; D018525:Germination / Q000502:physiology* / Q000528:radiation effects; D005875:Gibberellins / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects; D008027:Light; D009687:Nuclear Proteins / Q000502:physiology / Q000528:radiation effects; D010834:Phytochrome / Q000502:physiology; D010937:Plant Growth Regulators / Q000502:physiology*; D012639:Seeds / Q000502:physiology* / Q000528:radiation effects; D014157:Transcription Factors / Q000502:physiology / Q000528:radiation effects
D029681:Arabidopsis Proteins; D005875:Gibberellins; C480023:IMB1 protein, Arabidopsis; D009687:Nuclear Proteins; D010937:Plant Growth Regulators; D014157:Transcription Factors; D010834:Phytochrome; D000040:Abscisic Acid