Control of signaling pathways of brassinosteroids by the light and temperature conditions perceived by the plants

El crecimiento de los diferentes órganos de la planta está controlado por señales hormonales endógenas, que pueden verse afectadas por señales ambientales. Entre estas señales, las condiciones de luz y temperatura juegan un papel clave. La sombra causada por plantas vecinas y la temperatura incrementa los niveles de auxina y por lo tanto promueve el crecimiento del tallo. Los brasinoesteroides (BR) son potentes promotores del crecimiento, y los mutantes insensibles o deficientes en BR apenas responden a las señales de sombra. BZR1 y BES1 son reguladores positivos de la vía de señalización de BR que pueden interactuar con factores de transcripción que median la evitación de la sombra, como los PIFs (PHYTOCHROME-INTERACTING FACTORS), que regulan sinérgicamente la expresión de los genes promotores del crecimiento. En esta tesis investigamos si las señales de sombra y temperatura afectan la señalización por brasinoesteroides a nivel de BES1. En plántulas de Arabidopsis thaliana, la promoción del crecimiento del tallo es inducida por condiciones de sombra y temperaturas cálidas en mutantes de ganancia de función bes1-1D, en comparación con el genotipo salvaje. Medimos los niveles de fluorescencia nuclear mediante microscopía confocal, en plantas transgénicas pBES1:BES1:GFP. Las plantas expuestas a altas temperaturas o a sombra mostraron un aumento de fluorescencia nuclear en hipocótilos y una disminución en los cotiledones. Al introgresar estas plantas transgénicas en fondos mutantes como cop1 y pif4, observamos cambios diferenciales en la abundancia nuclear de BES1, por lo tanto COP1 y PIF4 interaccionan de manera diferencial en hipocótilo y cotiledón para regular a BES1 en tratamiento de sombra o temperaturas cálidas. Además medimos la expresión de BES1, mediante qRT-PCR, de manera independiente en ambos órganos y observamos una reducción en los niveles de expresión en respuesta a los tratamientos, particularmente en cotiledones. Los resultados expuestos en este trabajo muestran que un balance diferencial del control transcripcional y postranscripcional de BES1 por temperatura y sombra conduce a respuestas opuestas en el hipocótilo y los cotiledones, que a su vez se correlacionan con la respuesta de crecimiento.The growth of the different organs of the plant is controlled by endogenous hormonal signals, which can be affected by environmental cues. Among these signals, light and temperature conditions play a key role. Both, shade caused by neighboring plants and warm temperatures increment auxin levels and thereby promote stem growth. Brassinosteroids (BR) are potent promoters of growth, and BR-deficient or insensitive mutants barely respond to shade signals. BZR1 and BES1 are positive regulators of the BR signaling pathway that can interact with transcription factors that mediate shade avoidance like PHYTOCHROME-INTERACTING FACTORS, synergistically regulating the expression of growth-promoting genes. In this thesis we investigate whether shade and temperature cues affect BR signaling at the BES1 level. In Arabidopsis thaliana seedlings, the promotion of hypocotyl growth induced by shade or warm temperature conditions is enhanced in the bes1-1D gain-of-function mutant, compared to the wild type. We measured nuclear fluorescence levels by confocal microscopy, using transgenic plants bearing pBES1: BES1: GFP. The plants exposed to high temperatures or shade showed increased nuclear fluorescence in the hypocotyl and decreased nuclear fluorescence in the cotyledons. The analysis of the aforementioned trangene in the cop1 and pif4 mutant backgrounds revealed differential changes in the nuclear abundance of BES1. Therefore, COP1 and PIF4 differentially affect BES1 in the hypocotyl and the cotyledons exposed to either shade or warm temperatures. We also measured BES1 gene expression, by qRT-PCR, independently in both organs and we observed a reduction in expression levels in response to the shade and warm-temperature treatments, particularly in the cotyledons. We propose that the differential balance of transcriptional and posttranscriptional effects of shade or warm-temperature on BES1 in the hypocotyl and cotyledons leads to opposite BES1 responses, which in turn cause the opposite growth response.Fil: Costigliolo Rojas, María Cecilia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Shoot thermosensors do not fulfil the same function in the root

Increasing ambient temperature within the physiological, nonstressful, range promotes the growth of the hypocotyl (Gray et al., 1998) and of the primary root (Hanzawa et al., 2013), whilst reducing the expansion of the cotyledons (Hahm et al., 2020) of Arabidopsis thaliana seedlings.We currently know three thermosensors, phytochrome B (phyB) (Jung et al., 2016; Legris et al., 2016), EARLY FLOWERING 3 (ELF3) (Jung et al., 2020) and PHYTOCHROME INTERACTING FACTOR 7 (PIF7) (Chung et al., 2020), which were uncovered by their role in the control of hypocotyl growth.The root captures water and nutrients and provides an anchorage to the soil. Given these crucial functions, there is a growing interest in understanding the mechanisms involved in the control of primary root elongation by temperature (Hanzawa et al., 2013; Wang et al., 2016; Ibañez et al., 2017; Martins et al., 2017; Yang et al., 2017; Zhu et al., 2018; Fei et al., 2019; Feraru et al., 2019; Gaillochet et al., 2020; Fonseca de Lima et al., 2021; Lee et al., 2021). The aim of this work was to investigate whether the shoot thermosensors phyB, EFL3 and PIF7 fulfil the same function in the root.Fil: Borniego, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Costigliolo Rojas, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Casal, Jorge José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Perception of Sunflecks by the UV-B Photoreceptor UV RESISTANCE LOCUS8

Sunflecks, transient patches of light that penetrate through gaps in the canopy and transiently interrupt shade, are eco-physiologically and agriculturally important sources of energy for carbon gain, but our molecular understanding of how plant organs perceive and respond to sunflecks through photoreceptors remains limited. The UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8) is a recent addition to the list of plant photosensory receptors, and we have made considerable advances in our understanding of the physiology and molecular mechanisms of action of UVR8 and its signaling pathway. However, the function of UVR8 in the natural environment is poorly understood. Here, we show that the UVR8 dimer/monomer ratio responds quantitatively and reversibly to the intensity of sunflecks that interrupt shade in the field. Sunflecks reduced hypocotyl growth and increased CHALCONE SYNTHASE (CHS) and ELONGATED HYPOCOTYL5 gene expression and CHS protein abundance in wild-type Arabidopsis (Arabidopsis thaliana) seedlings, but the uvr8 mutant was impaired in these responses. UVR8 was also required for normal nuclear dynamics of CONSTITUTIVELY PHOTOMORPHOGENIC1. We propose that UVR8 plays an important role in the plant perception of and response to sunflecks.Fil: Moriconi, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Binkert, Melanie. Universidad de Ginebra; SuizaFil: Costigliolo Rojas, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Sellaro, Romina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Ulm, Roman. Universidad de Ginebra. Facultad de Ciencias; SuizaFil: Casal, Jorge José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

COP1 destabilizes DELLA proteins in Arabidopsis

Fil: Blanco Touriñán, Noel. Universidad Politécnica de Valencia. Instituto de Biologίa Molecular y Celular de Plantas. Valencia, Spain. - Consejo Superior de Investigaciones Cientίficas - Universidad Politécnica de Valencia. Instituto de Biologίa Molecular y Celular de Plantas. Valencia, Spain.Fil: Legris, Martina. CONICET. Fundaciόn Instituto Leloir. Instituto de Investigaciones Bioquίmicas de Buenos Aires, Buenos Aires, Argentina.Fil: Minguet, Eugenio G. Universidad Politécnica de Valencia. Instituto de Biologίa Molecular y Celular de Plantas. Valencia, Spain. - Consejo Superior de Investigaciones Cientίficas - Universidad Politécnica de Valencia. Instituto de Biologίa Molecular y Celular de Plantas. Valencia, Spain.Fil: Costigliolo Rojas, Cecilia. CONICET. Fundaciόn Instituto Leloir. Instituto de Investigaciones Bioquίmicas de Buenos Aires, Buenos Aires, Argentina.Fil: Nohales, Marίa A. University of Southern California. Department of Neurology, Keck School of Medicine, Los Angeles, CA, USA.Fil: Iniesto, Elisa. Consejo Superior de Investigaciones Cientίficas. Centro Nacional de Biotecnología. Departamento de Genética Molecular de Plantas. Madrid, Spain.Fil: Pacín, Manuel. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina. - CONICET – Universidad de Buenos Aires. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina.Fil: Casal, Jorge José. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina. - CONICET – Universidad de Buenos Aires. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina.DELLA transcriptional regulators are central components in the control of plant growth responses to the environment. This control is considered to be mediated by changes in the metabolism of the hormones gibberellins (GAs), which promote the degradation of DELLAs. However, here we show that warm temperature or shade reduced the stability of a GA-insensitive DELLA allele in Arabidopsis thaliana. Furthermore, the degradation of DELLA induced by the warmth preceded changes in GA levels and depended on the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). COP1 enhanced the degradation of normal and GA-insensitive DELLA alleles when coexpressed in Nicotiana benthamiana. DELLA proteins physically interacted with COP1 in yeast, mammalian, and plant cells. This interaction was enhanced by the COP1 complex partner SUPRESSOR OF phyA-105 1 (SPA1). The level of ubiquitination of DELLA was enhanced by COP1 and COP1 ubiquitinated DELLA proteins in vitro. We propose that DELLAs are destabilized not only by the canonical GA-dependent pathway but also by COP1 and that this control is relevant for growth responses to shade and warm temperature.grafs., fot

Rewiring of auxin signaling under persistent shade

Pucciariello, Ornella. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina.Legris, Martina. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Costigliolo Rojas, Cecilia. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Iglesias, María José. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Hernando, Carlos Esteban. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Dezar, Carlos. Instituto de Agrobiotecnología de Rosario. Rosario, Argentina.Vazquez, Martín P. Instituto de Agrobiotecnología de Rosario. Rosario, Argentina.Casal, Jorge José. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina.5612-5617Light cues from neighboring vegetation rapidly initiate plant shade - avoidance responses. Despite our detailed knowledge of the early steps of this response, the molecular events under prolonged shade are largely unclear. Here we show that persistent neighbor cues reinforce growth responses in addition to promoting auxin - responsive gene expression in Arabidopsis and soybean. However, while the elevation of auxin levels is well established as an early event, in Arabidopsis, the response to prolonged shade occurs when auxin levels have declined to the prestimulation values. Remarkably, the sustained low activity of phytochrome B under prolonged shade led to (i) decreased levels of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) in the cotyledons (the organs that supply auxin) along with increased levels in the vascular tissues of the stem, (ii) elevated expression of the PIF4 targets INDOLE-3-ACETIC ACID 19 (IAA19) and IAA29, which in turn reduced the expression of the growth-repressive IAA17 regulator, (iii) reduced abundance of AUXIN RESPONSE FACTOR 6, (iv) reduced expression of MIR393 and increased abundance of its targets, the auxin receptors, and (v) elevated auxin signaling as indicated by molecular markers. Mathematical and genetic analyses support the physiological role of this system - level rearrangement. We propose that prolonged shade rewires the connectivity between light and auxin signaling to sustain shade avoidance without enhanced auxin levels

Phytochrome B integrates light and temperature signals in Arabidopsis

Ambient temperature regulates many aspects of plant growth and development, but its sensors are unknown. Here, we demonstrate that the phytochrome B (phyB) photoreceptor participates in temperature perception through its temperature-dependent reversion from the active Pfr state to the inactive Pr state. Increased rates of thermal reversion upon exposing Arabidopsis seedlings to warm environments reduce both the abundance of the biologically active Pfr-Pfr dimer pool of phyB and the size of the associated nuclear bodies, even in daylight. Mathematical analysis of stem growth for seedlings expressing wild-type phyB or thermally stable variants under various combinations of light and temperature revealed that phyB is physiologically responsive to both signals. We therefore propose that in addition to its photoreceptor functions, phyB is a temperature sensor in plants

Functional convergence of growth responses to shade and warmth in Arabidopsis

Shade and warmth promote the growth of the stem, but the degree of mechanistic convergence and functional association between these responses is not clear. We analysed the quantitative impact of mutations and natural genetic variation on the hypocotyl growth responses of Arabidopsis thaliana to shade and warmth, the relationship between the abundance of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and growth stimulation by shade or warmth, the effects of both cues on the transcriptome and the consequences of warm temperature on carbon balance. Growth responses to shade and warmth showed strong genetic linkage and similar dependence on PIF4 levels. Temperature increased growth and phototropism even within a range where damage by extreme high temperatures is unlikely to occur in nature. Both cues enhanced the expression of growth-related genes and reduced the expression of photosynthetic genes. However, only warmth enhanced the expression of genes involved in responses to heat. Warm temperatures substantially increased the amount of light required to compensate for the daily carbon dioxide balance. We propose that the main ecological function of hypocotyl growth responses to warmth is to increase the access of shaded photosynthetic organs to light, which implies functional convergence with shade avoidance.Fil: Romero Montepaone, Sofía Iara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Sellaro, Romina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Hernando, Carlos Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Costigliolo Rojas, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Bianchimano, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Ploschuk, Edmundo Leonardo. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Cultivos Industriales; ArgentinaFil: Yanovsky, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Casal, Jorge José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Organ-specific COP1 control of BES1 stability adjusts plant growth patterns under shade or warmth

Under adverse conditions such as shade or elevated temperatures, cotyledon expansion is reduced and hypocotyl growth is promoted to optimize plant architecture. The mechanisms underlying the repression of cotyledon cell expansion remain unknown. Here, we report that the nuclear abundance of the BES1 transcription factor decreased in the cotyledons and increased in the hypocotyl in Arabidopsis thaliana under shade or warmth. Brassinosteroid levels did not follow the same trend. PIF4 and COP1 increased their nuclear abundance in both organs under shade or warmth. PIF4 directly bound the BES1 promoter to enhance its activity but indirectly reduced BES1 expression. COP1 physically interacted with the BES1 protein, promoting its proteasome degradation in the cotyledons. COP1 had the opposite effect in the hypocotyl, demonstrating organ-specific regulatory networks. Our work indicates that shade or warmth reduces BES1 activity by transcriptional and post-translational regulation to inhibit cotyledon cell expansion.Peer reviewe

COP1 destabilizes DELLA proteins in Arabidopsis

DELLA transcriptional regulators are central components in the control of plant growth responses to the environment. This control is considered to be mediated by changes in the metabolism of the hormones gibberellins (GAs), which promote the degradation of DELLAs. However, here we show that warm temperature or shade reduced the stability of a GA-insensitive DELLA allele in Arabidopsis thaliana. Furthermore, the degradation of DELLA induced by the warmth preceded changes in GA levels and depended on the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). COP1 enhanced the degradation of normal and GA-insensitive DELLA alleles when coexpressed in Nicotiana benthamiana. DELLA proteins physically interacted with COP1 in yeast, mammalian, and plant cells. This interaction was enhanced by the COP1 complex partner SUPRESSOR OF phyA-105 1 (SPA1). The level of ubiquitination of DELLA was enhanced by COP1 and COP1 ubiquitinated DELLA proteins in vitro. We propose that DELLAs are destabilized not only by the canonical GA-dependent pathway but also by COP1 and that this control is relevant for growth responses to shade and warm temperature.This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness and Agencia Española de Investigación/Fondo Europeo para el Desarrollo Regional/Unión Europea (grants BIO2016-79133-P to D.A. and BIO2013-46539-R and BIO2016-80551-R to V.R.); the European Union SIGNAT-Research and Innovation Staff Exchange (Grant H2020-MSCA-RISE-2014-644435 to M.A.B., D.A., and J.J.C.); the Argentinian Agencia Nacional de Promoción Científica y Tecnológica (Grant Proyectos de Investigación Científica y Tecnológica-2016-1459 to J.J.C.); Universidad de Buenos Aires (grant 20020170100505BA to J.J.C.); the National Institute of General Medical Sciences of the National Institutes of Health (awards R01GM067837 and R01GM056006 to S.A.K.); the German Research Foundation (DFG) under Germany’s Excellence Strategy/Initiative (Cluster of Excellence on Plant Sciences – Excellence Cluster EXC-2048/1, Project ID 390686111 to M.D.Z.); the International Max Planck Research School of the Max Planck Society; the Universities of Düsseldorf and of Cologne to T.B.; Nordrhein Westfalen Bioeconomy Science Center-FocusLabs CombiCom to N.H. and M.D.Z.; and Ministry of Education, Youth and Sports of the Czech Republic (Project LQ1601 Central European Institute of Technology 2020 to B.B. and M.C.). N.B.-T., E.I., and M.G.-L. were supported by Ministerio de Economía y Competitividad-Formación de Personal Investigador Program fellowships

COP1 destabilizes DELLA proteins in Arabidopsis

DELLA transcriptional regulators are central components in the control of plant growth responses to the environment. This control is considered to be mediated by changes in the metabolism of the hormones gibberellins (GAs), which promote the degradation of DELLAs. However, here we show that warm temperature or shade reduced the stability of a GA-insensitive DELLA allele in Arabidopsis thaliana. Furthermore, the degradation of DELLA induced by the warmth preceded changes in GA levels and depended on the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). COP1 enhanced the degradation of normal and GAinsensitive DELLA alleles when coexpressed in Nicotiana benthamiana. DELLA proteins physically interacted with COP1 in yeast, mammalian, and plant cells. This interaction was enhanced by the COP1 complex partner SUPRESSOR OF phyA-105 1 (SPA1). The level of ubiquitination of DELLA was enhanced by COP1 and COP1 ubiquitinated DELLA proteins in vitro. We propose that DELLAs are destabilized not only by the canonical GA-dependent pathway but also by COP1 and that this control is relevant for growth responses to shade and warm temperature.Fil: Blanco Touriñán, Noel. Universidad Politécnica de Valencia; EspañaFil: Legris, Martina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Minguet, Eugenio G.. Universidad Politécnica de Valencia; EspañaFil: Costigliolo Rojas, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Nohales, María A.. University of Southern California; Estados UnidosFil: Iniesto, Elisa. Consejo Superior de Investigaciones Científicas; EspañaFil: García León, Marta. Consejo Superior de Investigaciones Científicas; EspañaFil: Pacín, Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Heucken, Nicole. Universitat Dusseldorf; AlemaniaFil: Blomeier, Tim. Universitat Dusseldorf; AlemaniaFil: Locascio, Antonella. Universidad Politécnica de Valencia; EspañaFil: Cerný, Martin. Mendel University in Brno; República ChecaFil: Esteve Bruna, David. Universidad Politécnica de Valencia; EspañaFil: Díez Díaz, Mónica. Univerdiad Catolica de Valencia; EspañaFil: Brzobohatý, Bretislav. Mendel University in Brno; República ChecaFil: Frerigmann, Henning. Max Planck Institute for Plant Breeding Research; AlemaniaFil: Zurbriggen, Matías D.. Universitat Dusseldorf; AlemaniaFil: Kay, Steve A.. University of Southern California; Estados UnidosFil: Rubio, Vicente. Consejo Superior de Investigaciones Científicas; EspañaFil: Blázquez, Miguel A.. Universidad Politécnica de Valencia; EspañaFil: Casal, Jorge José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Alabadí, David. Universidad Politécnica de Valencia; Españ