9주차-16장_Signals from Sunlight 1 (1)

Phytochrome

A photoreceptor in plants that absorbs red and far-red light, playing a critical role in plant development.

Pr

The red light-absorbing form of phytochrome, inactive in the dark.

Pfr

The physiologically active form of phytochrome, which absorbs far-red light.

Photomorphogenesis

Plant growth and development in response to light.

Skotomorphogenesis

Growth in the absence of light, leading to elongated stems and closed cotyledons.

Negative regulator

A protein that inhibits growth, such as PIFs in phytochrome signaling.

PIFs

Phytochrome interacting factors that act as negative regulators of photomorphogenesis.

COP1

A constitutive photomorphogenesis protein that acts as E3 ligase for phytochromes.

Chlorophyll

A green pigment in plants that allows for the absorption of light for photosynthesis.

Shade avoidance syndrome

A plant response characterized by elongated growth in low light conditions to reach sunlight.

Photoreversibility

The ability of a process to be reversed by light, particularly seen in seed germination responses to red and far-red light.

Transcription factors

Proteins that control the transcription of genetic information from DNA to mRNA.

Photoreceptor

A sensory molecule that detects light and informs plant responses to light.

G-box

A specific DNA sequence recognized by transcription factors that regulates gene expression in response to light.

Circadian rhythm

The physiological process in plants that cycles about once every 24 hours, influenced by light.

Action spectrum

A graph showing the effectiveness of different wavelengths of light in stimulating a particular biological process.

Gene expression

The process by which genetic information is translated into functional products like proteins.

Ubiquitin

A small protein that tags other proteins for degradation within the cell.

De-etiolation

A process in plants where growth changes occur upon exposure to light, leading to a more typical leaf structure.

Germination

The process by which a seed develops into a new plant, often influenced by light.

Phototropism

The growth of a plant toward light, influenced by phytochrome signaling.

Autophosphorylation

A process through which a kinase attaches a phosphate group to itself as part of a signaling cascade.

Hinge region

A flexible segment in a protein that allows for movement and functional conformational changes.