Interaction of phytochromes A and B in the control of de-etiolation and flowering in pea

Weller, JL Beauchamp, N Kerckhoffs, LHJ Platten, JD Reid, JB

Jl. Weller et al., Interaction of phytochromes A and B in the control of de-etiolation and flowering in pea, PLANT J, 26(3), 2001, pp. 283-294

54

INGLESE

Article

Plant Sciences","Animal & Plant Sciences

PLANT JOURNAL

0960-7412 → ACNP

26

3

2001

283 - 294

ISI

0960-7412(200105)26:3<283:IOPAAB>2.0.ZU;2-9

The interactions of phytochrome A (phyA) and phytochrome B (phyB) in the ph otocontrol of vegetative and reproductive development in pea have been inve stigated using null mutants for each phytochrome. White-light-grown phyA ph yB double mutant plants show severely impaired de-etiolation both at the se edling stage and later in development, with a reduced rate of leaf producti on and swollen, twisted internodes, and enlarged cells in all stem tissues. PhyA and phyB act in a highly redundant manner to control de-etiolation un der continuous, high-irradiance red light. The phyA phyB double mutant show s no significant residual phytochrome responses for either de-etiolation or shade-avoidance, but undergoes partial de-etiolation in blue light. PhyB i s shown to inhibit flowering under both long and short photoperiods and thi s inhibition is required for expression of the promotive effect of phyA. Ph yA is solely responsible for the promotion of flowering by night-breaks wit h white light, whereas phyB appears to play a major role in detection of li ght quality in end-of-day light treatments, night breaks and day extensions . Finally, the inhibitory effect of phyB is not graft-transmissible, sugges ting that phyB acts in a different manner and after phyA in the control of flower induction.