The Role of Specialized Photoreceptors in the  Protection of Energy‐Rich Tissues

Abstract

Abstract:The perception and absorption of light by plants is a driving force in plant evolutionary history, as plants have evolved multiple photoreceptors to perceive different light attributes including duration, intensity, direction and quality. Plant photoreceptors interpret these signals from the light environment and mold plant architecture to maximize foliar light capture. As active sites of the production and accumulation of energy-rich products, leaves are targets of pests and pathogens, which have driven the selection of physiological processes to protect these energy-rich tissues. In the last ten years, several research groups have accumulated evidence showing that plant photoreceptors control specific molecular programs that define plant growth and immune processes. Here, we discuss recent knowledge addressing these roles in Arabidopsis and show that (1) plant immune responses affect energy acquisition and partitioning; (2) plant photoreceptors interpret the light environment and control growth and immune processes; and finally; (3) defense and light signaling pathways can be genetically manipulated to obtain plants able to grow and defend at the same time. This basic knowledge from Arabidopsis plants should lead new lines of applied research in crops.

Environmental effects of ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2017

“…Pests and diseases can account for a significant fraction (up to 25%) of pre-harvest crop losses in modern agricultural systems, and chemical controls are becoming increasingly regulated due to their potential negative environmental impacts. Manipulation of the molecular links between photoreceptors (see section 3.8) and plant defense responses, may help plant breeders to improve resistance to pests in agricultural and horticultural systems 234,[236][237][238]…”

COI1-dependent jasmonate signalling affects growth, metabolite production and cell wall protein composition in arabidopsis

“…The activation of defence responses redirects energy resources from primary metabolism at the expense of growth (Patil et al , 2014). Recently, the JASMONATE ZIM-DOMAIN (JAZ)–MYC transcriptional module was highlighted as the molecular basis behind the regulation of growth–defence balance (Major et al , 2017 b ), pointing towards a complex signalling hub mediating cross-talk between hormone and light signalling pathways (Major et al , 2017 a ). Major et al (2017 a ) proposed a model suggesting that growth and defence trade-offs are a consequence of a transcriptional network that evolved to maximize plant fitness, rather than just being the result of metabolic constraints.…”

“…Recently, the JASMONATE ZIM-DOMAIN (JAZ)–MYC transcriptional module was highlighted as the molecular basis behind the regulation of growth–defence balance (Major et al , 2017 b ), pointing towards a complex signalling hub mediating cross-talk between hormone and light signalling pathways (Major et al , 2017 a ). Major et al (2017 a ) proposed a model suggesting that growth and defence trade-offs are a consequence of a transcriptional network that evolved to maximize plant fitness, rather than just being the result of metabolic constraints. Taken together, our findings indicate that MeJA inhibits cell growth through the JA receptor COI1, in line with the notion that JAs contribute to regulating the trade-off between defence mode and plant growth (Yang et al , 2012; Noir et al , 2013).…”

Light Intensity- and Spectrum-Dependent Redox Regulation of Plant Metabolism

“…The light-dependent transcriptional regulation of this enzyme was observed in Arabidopsis [ 149 ]. In Arabidopsis loss-of-function mutants, it was shown that the HY5 and the ELONGATED HYPOCOTYL 5-HOMOLOG (HYH) transcription factors are involved in this process [ 7 , 97 , 150 , 151 ]. In addition, the light signalling-related COP1 and PIF transcription factors, promoting the degradation of HY5 and HYH, also participate in the regulation of nitrate reductase activity in Arabidopsis ( Figure 5 ) [ 150 ].…”

“…To perceive light signals from the sun, plants have different types of photoreceptors which include phytochromes (Phy), cryptochromes (Cry), phototropins (PHOT), and UV RESISTANCE LOCUS 8 (UVR8) [ 7 , 8 , 9 ]. Among photoreceptors, Phys (mostly phytochrome A (PhyA) and phytochrome B (PhyB)) perceive FRL and red light (RL).…”