Which of the following sequences correctly represents the phytochrome signal transduction pathway?
A) Red light → PIF3 activation → PIF3 into nucleus → light-responsive gene switched off
B) Red light → Pfr to Pr → Pr into nucleus → Pr-PIF3 complex → light-responsive gene regulation
C) UV light → PIF3 into nucleus → light responsive gene produces phytochrome → Pr to Pfr
D) Blue light → Pfr into nucleus → Pfr-PIF3 complex → light-responsive gene regulation
E) Red light → Pr to Pfr → Pfr into nucleus → Pfr-PIF3 complex → light-responsive gene regulation

Question

Quizplus · Accepted Answer

E) Red light converts Pr (phytochrome red-absorbing form) to Pfr (phytochrome far-red-absorbing form), which then moves into the nucleus and forms a complex with PIF3 (PHYTOCHROME INTERACTING FACTOR3), leading to the regulation of light-responsive genes. This is a key mechanism in plant responses to light.

Which of the Following Sequences Correctly Represents the Phytochrome Signal