TLS Online TPP Program

#Id: 9821

#XL - R Botany

A brief pulse of red light will induce a response, provided that the light is sufficiently bright, and conversely, very dim light will work if the irradiation time is long enough. 

This reciprocal relationship between fluence rate and time is known as the law of reciprocity

TLS Online TPP Program

#Id: 9822

#XL - R Botany

VLFRs and LFRs both obey the law of reciprocity

TLS Online TPP Program

#Id: 9823

#XL - R Botany

HIRs require prolonged or continuous exposure to light of relatively high irradiance, and the response is proportional to the irradiance

TLS Online TPP Program

#Id: 9824

#XL - R Botany

Plants that increase stem extension in response to shading are said to exhibit a shade avoidance response.

As shading increases, the R:FR ratio decreases. Shade means far red light

TLS Online TPP Program

#Id: 9825

#XL - R Botany

phyB–phyE, appear mostly light-stable in the plant and function primarily in the regulation of LFRs and of shade avoidance involving changes in the R:FR ratio.

TLS Online TPP Program

#Id: 9826

#XL - R Botany

phyA is rapidly degraded as Pfr and controls plant responses to VLFRs and the far-red HIRs.