Light signals generated by vegetation shade facilitate acclimation to low light in shade-avoider plants. Issue 4 (7th May 2021)

• Record Type: Journal Article
• Authors: Morelli, Luca; Paulišić, Sandi; Qin, Wenting; Iglesias-Sanchez, Ariadna; Roig-Villanova, Irma; Florez-Sarasa, Igor; Rodriguez-Concepcion, Manuel; Martinez-Garcia, Jaime F
• Is Part Of: Plant physiology. Volume 186:Issue 4(2021)
• Page Start: 2137
• Page End: 2151
• Publication Date: 2021-05-07
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1093/plphys/kiab206
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract: When growing in search for light, plants can experience continuous or occasional shading by other plants. Plant proximity causes a decrease in the ratio of R to far-red light (low R:FR) due to the preferential absorbance of R light and reflection of FR light by photosynthetic tissues of neighboring plants. This signal is often perceived before actual shading causes a reduction in photosynthetically active radiation (low PAR). Here, we investigated how several Brassicaceae species from different habitats respond to low R:FR and low PAR in terms of elongation, photosynthesis, and photoacclimation. Shade-tolerant plants such as hairy bittercress ( Cardamine hirsuta ) displayed a good adaptation to low PAR but a poor or null response to low R:FR exposure. In contrast, shade-avoider species, such as Arabidopsis ( Arabidopsis thaliana ), showed a weak photosynthetic performance under low PAR but they strongly elongated when exposed to low R:FR. These responses could be genetically uncoupled. Most interestingly, exposure to low R:FR of shade-avoider (but not shade-tolerant) plants improved their photoacclimation to low PAR by triggering changes in photosynthesis-related gene expression, pigment accumulation, and chloroplast ultrastructure. These results indicate that low R:FR signaling unleashes molecular, metabolic, and developmental responses that allow shade-avoider plants (including most crops) to adjust their photosynthetic capacity in anticipation of eventual shading by nearby plants. Abstract : Vegetation proximity light signals inform shade-avoider plants to adjust their photosynthetic capacity in anticipation of eventual shading by nearby plants.