A combination of plasma membrane sterol biosynthesis and autophagy is required for shade-induced hypocotyl elongation

• Published in: Nature communications Vol. 13; no. 1; pp. 5659 - 17
• Main Authors: Ince, Yetkin Çaka, Krahmer, Johanna, Fiorucci, Anne-Sophie, Trevisan, Martine, Galvão, Vinicius Costa, Wigger, Leonore, Pradervand, Sylvain, Fouillen, Laetitia, Van Delft, Pierre, Genva, Manon, Mongrand, Sebastien, Gallart-Ayala, Hector, Ivanisevic, Julijana, Fankhauser, Christian
• Format: Journal Article Web Resource
• Language: English
• Published: London Nature Publishing Group UK 10.10.2022; Nature Publishing Group; Nature Research; Nature Portfolio
• Subjects: 14; 14/35; 38; 38/15; 45; 45/91; 631/449/1736; 631/449/2653; 631/449/2686; 96; 96/95; Adaptation; Arabidopsis; Arabidopsis Proteins; Arabidopsis Proteins/genetics; Arabidopsis Proteins/metabolism; Arabidopsis/metabolism; Autophagy; Autophagy/genetics; Biochemistry, biophysics & molecular biology; Biochemistry, Genetics and Molecular Biology (all); Biochemistry, Molecular Biology; Biochimie, biophysique & biologie moléculaire; Biosynthesis; Botanics; Carbon; Carbon/metabolism; Cell Membrane; Cell Membrane/metabolism; Chemistry (all); Electromagnetic absorption; Elongation; Gene expression; Gene Expression Regulation, Plant; Gene sequencing; General Biochemistry, Genetics and Molecular Biology; General Chemistry; General Physics and Astronomy; Genetic analysis; Humanities and Social Sciences; Hypocotyl; Hypocotyl/genetics; Hypocotyls; Life Sciences; Light; Light quality; Lipid metabolism; Lipids; Multidisciplinary; Photosynthesis; Physics and Astronomy (all); Phytochrome; Phytochrome/metabolism; Plant growth; Plants (botany); Science; Science (multidisciplinary); Sciences du vivant; Shade; Sterols; Sterols/metabolism; Vegetal Biology; Cell Membrane; Plant; Arabidopsis Proteins; Hypocotyl; Sterols; Arabidopsis; Light; Gene Expression Regulation; Phytochrome; Lipids; Autophagy; Carbon
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-33384-9

Plant growth ultimately depends on fixed carbon, thus the available light for photosynthesis. Due to canopy light absorption properties, vegetative shade combines low blue (LB) light and a low red to far-red ratio (LRFR). In shade-avoiding plants, these two conditions independently trigger growth adaptations to enhance light access. However, how these conditions, differing in light quality and quantity, similarly promote hypocotyl growth remains unknown. Using RNA sequencing we show that these two features of shade trigger different transcriptional reprogramming. LB induces starvation responses, suggesting a switch to a catabolic state. Accordingly, LB promotes autophagy. In contrast, LRFR induced anabolism including expression of sterol biosynthesis genes in hypocotyls in a manner dependent on PHYTOCHROME-INTERACTING FACTORs (PIFs). Genetic analyses show that the combination of sterol biosynthesis and autophagy is essential for hypocotyl growth promotion in vegetative shade. We propose that vegetative shade enhances hypocotyl growth by combining autophagy-mediated recycling and promotion of specific lipid biosynthetic processes. Plants subject to vegetative shade receive a low quantity of blue light (LB) and a low ratio of red to far-red light (LFLR). Here the authors show that while LB induces autophagy, LFLR leads to changes in lipid metabolism, and propose that these processes may contribute to shade avoidance responses.