Shade avoidance syndrome in 4D: illuminating a role for transcriptional repression of protein biogenesis genes

Abstract

The leaf is the main organ for sunlight absorption and information acquisition from the environment. Such roles have granted the leaf with tremendous plasticity to secure the conversion of photons into sugars and to outcompete neighboring plants (Fritz et al., 2018). While chlorophylls absorb mainly blue (B, 480 nm) and red (R, 660 nm) photons from incoming sunlight to drive photosynthesis and produce organic molecules, phytochromes extract information from reflected light of surrounding green tissues by detecting the ratio of R to far-red (FR, 730 nm) light to shape the final canopy architecture (Ballaré and Casal, 2000; Major et al., 2017). The two photoconvertible forms of phytochrome absorb R and FR photons from the light environment with different efficiency, thus a drop in R:FR ratio detected by phytochromes reveals the proximity of competitors (Ballaré et al., 1990).