ELONGATED HYPOCOTYL5 (HY5) and HY5 HOMOLOGUE (HYH) maintain shade avoidance suppression in UV-B.

Autor: Sharma A; School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK., Pridgeon AJ; School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK., Liu W; School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK., Segers F; School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK., Sharma B; School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK., Jenkins GI; School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK., Franklin KA; School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK.
Jazyk: angličtina
Zdroj: The Plant journal : for cell and molecular biology [Plant J] 2023 Sep; Vol. 115 (5), pp. 1394-1407. Date of Electronic Publication: 2023 Jun 15.
DOI: 10.1111/tpj.16328
Abstrakt: Reductions in red to far-red ratio (R:FR) provide plants with an unambiguous signal of vegetational shade and are monitored by phytochrome photoreceptors. Plants integrate this information with other environmental cues to determine the proximity and density of encroaching vegetation. Shade-sensitive species respond to reductions in R:FR by initiating a suite of developmental adaptations termed shade avoidance. These include the elongation of stems to facilitate light foraging. Hypocotyl elongation is driven by increased auxin biosynthesis promoted by PHYTOCHROME INTERACTING FACTORs (PIF) 4, 5 and 7. UV-B perceived by the UV RESISTANCE LOCUS 8 (UVR8) photoreceptor rapidly inhibits shade avoidance, in part by suppressing PIF4/5 transcript accumulation and destabilising PIF4/5 protein. Here, we show that longer-term inhibition of shade avoidance is sustained by ELONGATED HYPOCOTYL 5 (HY5) and HY5 HOMOLOGUE (HYH), which regulate transcriptional reprogramming of genes involved in hormone signalling and cell wall modification. HY5 and HYH are elevated in UV-B and suppress the expression of XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE (XTH) genes involved in cell wall loosening. They additionally increase expression GA2-OXIDASE1 (GA2ox1) and GA2ox2, encoding gibberellin catabolism enzymes that act redundantly to stabilise the PIF-inhibiting DELLA proteins. UVR8 therefore regulates temporally distinct signalling pathways to first rapidly inhibit and subsequently maintain suppression of shade avoidance following UV-B exposure.
(© 2023 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.)
Databáze: MEDLINE
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