phytochrome
plant pigment protein that absorbs red light and then initiates physiological responses governing light sensitive processes such as germination, growth and flowering. Exists in two forms, pr and pfr, that are interconverted by light.
A plant pigment that exists between two forms, phytochrome 660 and phytochrome 725. They switch between one or the other depending on what time of the day it is, daytime or night time.
This tutorial elaborates on the effect of light on plant growth. It describes how different plants require different amounts of light in a day. The amount of time that a plant requires is called the critical period. Learn more about this topic in this tutorial...
Plants, like animals, produce hormones to regulate plant activities, including growth. They need these hormones to respond well to their environment and to sustain growth, development, and dispersal. Plant biologists recognize five major groups of plant hormones: auxins, gibberellins, ethylene, cytokinins, and abscisic acid. Find out in this guide the importance of each hormone in the life of a plant...
