FIGURE 3.

Example of plant developmental responses to changes in environmental conditions. (A) Both shaded light (i.e., a reduction in the red to far-red (R/F) photon ratio) and an increase in temperature induce the elongation of the petiole, a reduction of leaf area and an upward movement of the leaves. These responses are mediated by the activation of PIF transcription factors. (B) The increase of leaf margin dissection induced by cold in the genus Capsella is mediated by the transcriptional activation of RCO. (C) Deepwater rice species are able to activate elongation growth depending on the water level. In flooded conditions, SNORKEL 1 and 2 are activated and promote cell elongation through GA signaling. (D) Some aquatic species are able to develop two types of leaves each adapted to either submerged or terrestrial conditions. The switch between leaf forms is triggered by several environmental factors including light, temperature and humidity. The decrease in leaf margin dissection in terrestrial conditions is associated with the inhibition of the KNOXI-CUC gene modules. (E) An increase in CO₂ induces a decrease in stomata (outlined in green) density through the activation of EPF2 and of the protease CRSP. CRSP cleaves and activates EPF2 which, then, inhibits stomata differentiation.