Figure 2.

Uncoupled Decrease in HIR Compared with VLFR and LFR after Deletion of a Lhcb1*2 Promoter in Transgenic Arabidopsis Plants.

(A) Schematic representation of the constructs used in the present set of experiments. X represents the variable 5′ ends, as indicated in (B) to (D).

(B) Promoter deletion from −453 to −134 eliminates the HIR. Etiolated seedlings were exposed to hourly pulses of FR light, hourly pulses of R light, or continuous FR light. Data are means ±se of six to 10 independently transformed Arabidopsis lines. For each line, activity was normalized to the values observed after treatment with R light pulses.

(C) Comparative effects on VLFR, LFR, and HIR. VLFR, LFR, and HIR were calculated from the data in (B) (±se of the difference). The VLFR was calculated as the difference between the activities under hourly FR light pulses and those of the dark controls, the HIR was calculated as the difference between the responses to continuous FR light and those to hourly pulses of FR light, and the LFR was calculated as the difference between the responses to hourly pulses of R light and those to hourly pulses of FR light.

(D) Data corresponding to single representative transgenic lines (average ±se of three replicate samples). 4-MU, 4-methylumbelliferone.