What does phytochrome B do?
Table of Contents
What does phytochrome B do?
Phytochrome B (phyB) is the main photoreceptor controlling growth in Arabidopsis seedlings exposed to different shade conditions (5). Like others in the phytochrome family, phyB is a homodimeric chromoprotein, with each subunit harboring a covalently bound phytochromobilin chromophore.
What are the types of phytochrome?
Phytochromes are a class of photoreceptor in plants, bacteria and fungi used to detect light. They are sensitive to light in the red and far-red region of the visible spectrum and can be classed as either Type I, which are activated by far-red light, or Type II that are activated by red light.
Is phytochrome involved in Photomorphogenesis?
Plants use phytochrome to detect and respond to red and far-red wavelengths. Phytochromes are signaling proteins that promote photomorphogenesis in response to red light and far-red light.
What are cryptochromes and Phototropins?
Cryptochromes regulate plant development and photomorphogenesis whereas phototropins are primarily implicated in photomovement responses such as phototropism and chloroplast relocation.
How many phytochromes are in Arabidopsis?
five phytochromes
In Arabidopsis thaliana, there are five phytochromes, designated phytochrome A (phyA) to phyE. They are encoded by five distinct members of the phytochrome gene family and are classified into two groups according to their stability in light (Sharrock and Quail, 1989).
What are two forms of phytochrome?
Phytochrome exists in two interconvertible forms The forms are named by the color of light that they absorb maximally: Pr is a blue form that absorbs red light (660 nm) and Pfr is a blue-green form that absorbs far-red light (730 nm).
How does phytochrome control photomorphogenesis?
Therefore, phytochromes mediate photomorphogenic development by inhibiting the function of negative regulators of photomorphogenesis, i.e., PIFs and COP1/SPA complexes. The former is degraded in the presence of phytochromes, and the latter is dissociated by binding with phytochromes (Figure 2).
What is photomorphogenesis and Skotomorphogenesis?
One of the most dramatic changes in plant growth and development occurs during the transition from life in the dark just after germination, to life in a light environment when the seedling emerges from soil. Development in darkness is referred to as skotomorphogenesis, whereas development in the light is referred to as …
Where are phytochromes found in plants?
Plant phytochromes are present in the cytoplasm in their dark state and are transported into the nucleus upon light activation.
Which pigment is responsible for photomorphogenesis in plants?
Phytochrome
Which pigment is associated with photomorphogenesis? Phytochrome is associated with photomorphogenesis. A number of photomorphogenic responses are mediated by a chromoprotein known as phytochrome. It acts as a photoreceptor for red and far-red light.
What role do phytochromes play in plants?
Phytochromes regulate light-induced developmental transitions as well as adaptation to growth under dense canopy. Plant phytochromes have antagonistic and synergistic roles in regulating photoperiodic flowering in Arabidopsis.
