Figure 6.

ChphyA Has a Stronger Activity Than AtphyA in Repressing Shade-Induced Hypocotyl Elongation.

(A) Cartoon detailing the constructs used to complement Arabidopsis phyA-501 mutant plants.

(B) Relative PHYA:TUB in etiolated seedlings of At^WT, phyA-501, and selected phyA>AtPHYA (blue bars) and phyA>ChPHYA (red bars) complementation lines. Seedlings were grown as indicated in Supplemental Figure 8. Values are means and se of four independent biological replicates relative to PHYA:TUB levels of etiolated At^WT seedlings.

(C) Cartoon illustrating how phyA activity in simulated shade was established as differences in hypocotyl length between simulated shade- and W-grown seedlings (Hyp_W+FR-Hyp_W). Seedlings were grown for 2 d under W and then for another 5 d under W or W+FR (R:FR = 0.02), when hypocotyls were measured.

(D) Hyp_W+FR-Hyp_W in seedlings of At^WT, phyA-501, and selected phyA>AtPHYA (blue bars) and phyA>ChPHYA (red bars) complementation lines. Values are the difference of means of hypocotyl length between seedlings grown under W+FR (Hyp_W+FR) and under W (Hyp_W). se were propagated accordingly.

(E) Cartoon illustrating how phyA activity in deetiolation was established as differences in hypocotyl length between dark- and FR-grown seedlings (Hyp_D-Hyp_FR). Seedlings were grown as indicated in Figure 3B.

(F) Hyp_D-Hyp_FR in seedlings of At^WT, phyA-501, and selected phyA>AtPHYA (blue bars) and phyA>ChPHYA (red bars) complementation lines. Values are the difference of means of hypocotyl length between seedlings grown in the dark (Hyp_D) and under FR (Hyp_FR). se were propagated accordingly.

In (C) and (E), mutant phyA-501 seedlings have no phyA activity.