phytochrome

American  

[fahy-tuh-krohm] / ˈfaɪ təˌkroʊm /

noun

Botany.

1. a plant pigment that is associated with the absorption of light in the photoperiodic response and that may regulate various types of growth and development.

---

phytochrome British  

/ ˈfaɪtəʊˌkrəʊm /

noun

1. botany a blue-green pigment existing in two interchangeable forms, present in most plants, that mediates many light-dependent processes, including photoperiodism and the greening of leaves

---

phytochrome Scientific  

/ fī′tə-krōm′ /

1. Any of a group of cytoplasmic pigments found in green plants and some green algae that absorb red light and regulate dormancy, seed germination, and flowering. Phytochromes consist of a bile pigment attached to a protein, and occur in an active and inactive form, each of which can be converted into the other depending on the wavelength of red light that is absorbed.

---

Etymology

Origin of phytochrome

First recorded in 1890–95; phyto- + -chrome

Example Sentences

Though all of them contain the temperature-sensing protein phytochrome B, some of these organelles are sensitive to temperature, and others aren't.

From Science Daily • May 7, 2024

Therefore, at dawn, all the phytochrome molecules in a leaf quickly convert to the active Pfr form, and remain in that form until sunset.

From Textbooks • Jun. 9, 2022

In short, plant shoots use the phytochrome system to grow away from shade and towards light.

From Textbooks • Jun. 9, 2022

Plants also use the phytochrome system to sense the change of season.

From Textbooks • Jun. 9, 2022

Red light converts the phytochrome to its active form Pr which can be converted to the inactive form Pfr by far red light.

From Textbooks • Jun. 9, 2022