IIB   20738
INSTITUTO DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Functional analysis of the UVR8 photoreceptor from the monocotyledonous Zea mays
Autor/es:
FERNÁNDEZ, MARÍA BELÉN; LAMATTINA, LORENZO; CASSIA, RAÚL
Revista:
PLANT GROWTH REGULATION
Editorial:
SPRINGER
Referencias:
Año: 2020
ISSN:
0167-6903
Resumen:
Low UV-B fuence is a signaling stimulus that regulates various physiological processes and induces photomorphogenicresponses in plants. The specifc UV-B receptor UVR8 is a key component in these processes. Although UVR8 sequence isconserved, few homologs have been cloned and reported to be functional. Here we show the cloning and functional analysis ofZea mays UVR8 (ZmUVR8). ZmUVR8 presents 73% of identity with AtUVR8, maintaining the key tryptophan responsible ofUV-B perception. ZmUVR8 also contains the VP domain, involved in the interaction with the proteins CONSTITUTIVELYPHOTOMORPHOGENIC 1 (COP1) and REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1). Whereas UVR8was expressed in non-irradiated Arabidopsis and maize leaves, after 2 h of UV-B irradiation, its expression was reduced.The expression of chalcone synthase (CHS), involved in favonoid biosynthesis and regulated by UVR8, was increased inirradiated Arabidopsis and maize leaves. Arabidopsis uvr8-1 null mutant was complemented with ZmUVR8 driven by theCaMV-35S promoter and fused to eGFP. ZmUVR8-eGFP fusion was mainly localized in nuclei of transgenic lines, irrespective of UV-B treatments. UV-B suppressed hypocotyl elongation in wild type (WT) Arabidopsis plants, whereas in uvr8-1hypocotyl growth was observed. However, hypocotyl elongation was reduced in UV-B irradiated transgenic lines complemented with ZmUVR8. Moreover, CHS and transcription factor HY5 (ELONGATED HYPOCOTYL 5) expression werealso restored in these plants. These results confrm that ZmUVR8 is similar enough to AtUVR8 to restore UV-B perceptionand signaling in Arabidopsis mutant uvr8-1, thus being a functional UV-B photoreceptor. That reinforce the importance ofUVR8 as a functional UV-B-responsive regulator in land plants