Plant Physiology 7) In the shade avoidance response, PIF transcription factors p
ID: 268474 • Letter: P
Question
Plant Physiology
7) In the shade avoidance response, PIF transcription factors promote the expression of cell elongation genes because the low ratio of red:far red light converts Pr to Pr such that Pr is not present to target PIF for ubiquitination and degradation, AND gibberellic acid promotes ubiquitination and degradation of DELLA repressors, which otherwise bind to and inhibit PIF transcription factors. A) TRUE B) FALSE C) WHAAAAAT? In a classic experiment, Ian Sussex carefully separated a leaf primordia from the adjacent apical meristem. What was observed? 8) A) The leaf developed normally C) The leaf primordia grew out as branch D) The leaf grew out as needle-like structure instead of a flat blade E) The leaf primordia transitioned to a flower primordiaExplanation / Answer
7. TRUE
PIF proteins promote cell elongation.
Pr is converted to Pfr by red light.
Pfr is converted to Pr by far-red light.
Pfr form inhibits PIF binding to their target DNA.
PIF proteins promote skotomorphogenesis.
8. Option B is correct.
When the apical meristem is punctured, the leaf primordia transitioned into a second apical meristem.