Oscar Lorenzo

• Research Director at University of Salamanca

The cysteine/arginine (Cys/Arg) branch of the N-degron pathway controls the stability of certain proteins with methionine (Met)-Cys N-termini, initiated by Met cleavage and Cys oxidation. In seeding plants, target proteins include the Group VII Ethylene Response Factors, which initiate adaptive responses to low oxygen (hypoxic) stress, as well as V...

Nitro-fatty acids (NO2-FAs) have emerged as key components of nitric oxide (NO) signalling in eukaryotes. We previously described how nitro-linolenic acid (NO2-Ln), the major NO2-FA detected in plants, regulates S-nitrosoglutathione (GSNO) levels in Arabidopsis (Arabidopsis thaliana). However, the underlying molecular mechanisms remain undefined. H...

This article comments on: Li Z, Zhang D, Liang X, Liang J. 2024. Receptor for Activated C Kinase 1 counteracts ABSCISIC ACID INSENSITIVE5-mediated inhibition of seed germination and post-germinative growth in Arabidopsis. Journal of Experimental Botany 75, 3932–3945.

Autophagy is a cell recycling mechanism that degrades cytoplasmic components. Although classically considered a non-selective bulk degradation mechanism, autophagy also functions selectively. Here, we investigate the impact of autophagy on seed development by studying the autophagy-related (ATG) genes AtATG5 and AtATG7 in Arabidopsis, focusing on t...

Nitric oxide (NO) is a gasotransmitter required in a broad range of mechanisms controlling plant development and stress conditions. However, little is known about the specific role of this signaling molecule during lipid storage in the seeds. Here, we show that NO is accumulated in developing embryos and regulates the fatty acid profile through the...

Environmental conditions greatly impact plant growth and development. In the current context of both global climate change and land degradation, abiotic stresses usually lead to growth restriction limiting crop production. Plants have evolved to sense and respond to maximize adaptation and survival; therefore, understanding the mechanisms involved...

Plant root growth and developmental capacities reside in a few stem cells of the root apical meristem (RAM). Maintenance of these stem cells requires regenerative divisions of the initial stem cell niche (SCN) cells, self-maintenance, and proliferative divisions of the daughter cells. This ensures sufficient cell diversity to guarantee the developm...

High seed quality is key to agricultural production, which is increasingly affected by climate change. We studied the effects of drought and elevated temperature during seed production on key seed quality traits of two genotypes of malting barley (Hordeum sativum L.). Plants of a “Hana-type” landrace (B1) were taller, flowered earlier and produced...

High seed quality is key to agricultural production, which is increasingly affected by climate change. We studied the effects of drought and elevated temperature during seed production on key seed quality traits of two genotypes of malting barley ( Hordeum sativum L.). Plants of a “Hana-type” landrace (B1) were taller, flowered earlier and produced...

Following germination, seedlings grown in light show a photomorphogenic development with open and green cotyledons and a robust root system. The light perception by the photoreceptors activate autotrophic photosynthetic metabolism to sustain growth of the whole plant. Several studies have evaluated transcriptional responses to light signals. Nevert...

The interplay between the phytohormone abscisic acid (ABA) and the gasotransmitter nitric oxide (NO) regulates seed germination and post-germinative seedling growth. We show that GAP1 (germination in ABA and cPTIO 1) encodes the transcription factor ANAC089 with a critical membrane-bound domain and extranuclear localization. ANAC089 mutants lacking...

Hormone patterns tailor cell fate decisions during plant organ formation. Among them, auxins and cytokinins are critical phytohormones during early development. Nitric oxide (NO) modulates root architecture by the control of auxin spatial patterns. However, NO involvement during the coordination of shoot organogenesis remains unclear. Here, we expl...

The cue1 nitric oxide (NO) overproducer mutants are impaired in a plastid phosphoenolpyruvate/phosphate translocator, mainly expressed in Arabidopsis thaliana roots. cue1 mutants present an increased content of arginine, a precursor of NO in oxidative synthesis processes. However, the pathways of plant NO biosynthesis and signaling have not yet bee...

Plants are aerobic organisms that have evolved to maintain specific requirements for oxygen (O2) leading to a correct respiratory energy supply during growth and development. There are certain plant developmental cues and biotic or abiotic stress responses where O2 levels are scarce. This O2 deprivation known as hypoxia may occur in hypoxic niches...

This article comments on: Garg A, Kirchler T, Fillinger S, Wanke F, Stadelhofer B, Stahl M, Chaban C. 2019. Targeted manipulation of bZIP53 DNA-binding properties influences Arabidopsis metabolism and growth. Journal of Experimental Botany 70, 5659–5671.

Plants are sessile organisms that need to complete their life cycle by the integration of different abiotic and biotic environmental signals, tailoring developmental cues and defense concomitantly. Commonly, stress responses are detrimental to plant growth and despite intensive efforts have been made to understand both plant development and defense...

Significance We developed a computational pipeline that uses gene expression datasets for inferring relationships among genes and predicting their importance. We showed that the capacity of our pipeline to integrate spatial and temporal transcriptional datasets improves the performance of inference algorithms. The combination of this pipeline with...

The two Arabidopsis thaliana mutants, aba1 and max4, were previously identified as sharing a number of co-regulated genes with both the flu mutant and Arabidopsis cell suspension cultures exposed to high light (HL). On this basis, we investigated whether aba1 and max4 were generating high amounts of singlet oxygen (¹O2) and activating ¹O2-mediated...

Identifying the transcription factors (TFs) and associated networks involved in stem cell regulation is key for understanding the initiation and growth of plant tissues and organs. Although many TFs have been shown to have a role in the Arabidopsis root stem cells, a comprehensive view of the transcriptional signature of the stem cells is lacking....

Salicylic acid (SA) and jasmonic acid (JA) cross-communicate in the plant immune signaling network to finely regulate induced defenses. In Arabidopsis, SA antagonizes many JA-responsive genes, partly by targeting the ETHYLENE RESPONSE FACTOR (ERF)- type transcriptional activator ORA59. Members of the ERF transcription factor family typically bind t...

The versatility of nitric oxide (NO) as a free radical that mediates numerous biological functions within early plant development is widely accepted. NO action in seed germination and root developmental processes involves a complex signaling pathway that includes the cellular redox levels, the posttranslational modification of specific proteins by...

Supplementary Figures 1-12 and Supplementary References

Plant survival depends on seed germination and progression through post-germinative developmental checkpoints. These processes are controlled by the stress phytohormone abscisic acid (ABA). ABA regulates the basic leucine zipper transcriptional factor ABI5, a central hub of growth repression, while the reactive nitrogen molecule nitric oxide (NO) c...

During the past two decades, nitric oxide (NO) has evolved from a mere gaseous free radical to become a new messenger in plant biology with an important role in a plethora of physiological processes. This molecule is involved in the regulation of plant growth and development, pathogen defence and abiotic stress responses, and in most cases this is...

The Executer1 and Executer2 proteins have a fundamental role in the signalling pathway mediated by singlet oxygen in chloroplast; nonetheless, not much is known yet about their specific activity and features. Herein, we have followed a differential-expression proteomics approach to analyse the impact of Executer on the soluble chloroplast protein a...

Nitric oxide (NO) is a unique reactive nitrogen molecule with an array of signalling functions that modulates plant developmental processes and stress responses. To explore the mechanisms by which NO modulates root development, we used a pharmacological approach and NO deficient mutants to unravel the role of NO in establishing auxin distribution p...

Light-grown Arabidopsis thaliana cell suspension culture (ACSC) were subjected to mild photooxidative damage with Rose Bengal (RB) with the aim of gaining a better understanding of singlet oxygen-mediated defence responses in plants. Additionally, ACSC were treated with H2O2 at concentrations that induced comparable levels of protein oxidation dama...

The name, e-mail address and affiliation of members of the TRANSPLANTA Consortium participating in this work are listed in Table S1. SUMMARY Transcription factors (TFs) are key regulators of gene expression in all organisms. In eukaryotes, TFs are often represented by functionally redundant members of large gene families. Overexpression might prove...

Understanding of seed ageing, which leads to viability loss during storage, is vital for ex situ plant conservation and agriculture alike. Yet the potential for regulation at the transcriptional level has not been fully investigated. Here, we studied the relationship between seed viability, gene expression and glutathione redox status during artifi...

Nitric oxide (NO) is involved in a variety of physiological processes during plant life acting as a key signalling molecule. Our recent research has uncovered a role of NO on primary root growth in Arabidopsis (1, 2). However, in spite of its relevance as a plant growth and stress regulator, our current knowledge about the NO signalling pathway is...

Auxin transport is a central process in plant growth and development and as a result is highly regulated. The amount and direction of auxin transport is defined by a set of auxin influx and efflux carriers with precise localization that lead to long-distance polar auxin transport. These auxin transport proteins are regulated by transcriptional and...

Microbe-Associated Molecular Patterns and virulence effectors are recognized by plants as a first step to mount a defence response against potential pathogens. This recognition involves a large family of extracellular membrane receptors and other immune proteins located in different sub-cellular compartments. We have used phage-display technology t...

Microarray analysis of Pst(avrRpt2) bio-panning. Normalized values for log B/L signals. (TXT)

Microarray analysis of Pa bio-panning. Normalized values for log B/L signals. (TXT)

153 significant genes selected from Pst ( avrRpt2 ) bio-panning. (TXT)

Proteins in the 472-gene set that produced immune interactions in PPIN-1. (TXT)

Gene elements spotted on A. thaliana microarrays that were detected in T7LAtPs and T7LATPa libraries. Graphs represent the number of gene elements that produced signal-to-background ratios below the values specified in the X-axe. The red line shows the threshold ratio produced from hybridization with control elements (genome aliens). A total of 4,2...

(A) Competition between T7-ATERF-1 and T7-C1 phage for binding to LPS. Mixtures of phage containing 1∶1 (input 1), 1∶6 (input 2) and 1∶17 (input 3) of T7-ATERF-1:T7-C1 clones were panned against 2.5 mM of agarose-coupled LPS. Uncoupled agarose (Agar) was used as the control for non-specific binding. (B) Competition between T7-ATUBA1 and T7-C1 phage...

Significance analysis of microarrays, p-values and fold-changes for 26,450 probes. Fold-change (FC) is provided as the absolute value, up or down-regulated. Bio-panning rounds 1 to 5 (1B to 5B) against Pa, Pst or Pst(avrRpt2) (avr) strains. (XLS)

Corrected p-values and fold-change (FC) for the 472-gene set. p-values before and after FDR correction are shown for each round of selection. (XLS)

58-gene set shown in Figure 7A . (TXT)

2-gene set shown in Figure 7A . (TXT)

Microarray analysis of Pst bio-panning. Normalized values for log B/L signals. (TXT)

93-gene set shown in Figure 7A . (TXT)

96-gene set shown in Figure 7A . (TXT)

Genes in the 472-gene set that are also transcriptionally regulated upon pathogen challenge. (XLSX)

101 significant genes selected from Pa bio-panning. (TXT)

318 significant genes selected from Pst bio-panning. (TXT)

220-gene set shown in Figure 7A . (TXT)

3-gene set shown in Figure A. (TXT)

Understanding of seed ageing, which leads to viability loss during storage, is vital for ex situ plant conservation and agriculture alike. Yet the potential for regulation at the transcriptional level has not been fully investigated. Here, we studied the relationship between seed viability, gene expression and glutathione redox status during artifi...

Nitric oxide (NO) is a highly inducible molecule and overaccumulated during stress responses, such as drought, cold and pathogen infection. Several key developmental processes within a plant life cycle have been reported to be signaled by this gaseous molecule, and among them seed germination, de-etiolation, gravitropic response or root growth are...

Nitric oxide (NO) is a highly inducible molecule and overaccumulated during stress responses, such as drought, cold and pathogen infection. Several key developmental processes within a plant life cycle have been reported to be signaled by this gaseous molecule, and among them seed germination, de-etiolation, gravitropic response or root growth are...

The phytohormone ABA regulates seed germination and stress responses. The identification of clade A protein phosphatase type 2C (PP2C)-interacting proteins PYRABACTIN RESISTANCE 1 (PYR1)/RCAR (REGULATORY COMPONENT OF ABA RECEPTOR) and PYR1-LIKEs (PYLs) as ABA receptors has been a major advance in understanding this process. Here, our aim was to ide...

Can Arabidopsis cell suspension cultures (ACSC) provide a useful working model to investigate genetically-controlled defense responses with signaling cascades starting in chloroplasts? In order to provide a convincing answer, we analyzed the early transcriptional profile of Arabidopsis cells at high light (HL). The results showed that ACSC respond...

Nitric oxide (NO) is considered a key regulator of plant developmental processes and defense, although the mechanism and direct targets of NO action remain largely unknown. We used phenotypic, cellular, and genetic analyses in Arabidopsis thaliana to explore the role of NO in regulating primary root growth and auxin transport. Treatment with the NO...

The early transcriptional defense responses and reactive oxygen species (ROS) production in Arabidopsis (Arabidopsis thaliana) cell suspension culture (ACSC), containing functional chloroplasts, were examined at high light (HL). The transcriptional analysis revealed that most of the ROS markers identified among the 449 transcripts with significant...

Transcriptional regulation depends on the specificity of transcription factors (TFs) recognizing cis regulatory sequences in the promoters of target genes. Current knowledge about DNA-binding specificities of TFs is based mostly on low- to medium-throughput methodologies, revealing DNA motifs bound by a TF with high affinity. These strategies are t...

Expression data from water-stratified Arabidopsis mads-box agl 67 mutant and wild-type Col-0 seeds and then ABA-treated for 3 hours. mads-box agl 67 mutant seeds showed abscisic acid (ABA) insensitive phenotypes. The AGAMOUS-LIKE 67 gene encodes a transcription factor nuclear-localized, as observed by transiently transformed epidermal onion cells,...

Expression data from water-stratified Arabidopsis anac089-2 mutant and wild-type Col-0 seeds and then ABA-treated for 3 hours. Through a genetic screening in 3μM (+)-S-ABA, we have isolated the anac089-2 mutant, which was obtained from fast neutron-mutagenized Col M2 seeds. This mutant showed ABA-insensitive phenotypes in the transition from dorman...

Expression data from water-stratified Arabidopsis mads-box agl 67 mutant and wild-type Col-0 seeds and then ABA-treated for 3 hours. mads-box agl 67 mutant seeds showed abscisic acid (ABA) insensitive phenotypes. The AGAMOUS-LIKE 67 gene encodes a transcription factor nuclear-localized, as observed by transiently transformed epidermal onion cells,...

La germinación de semillas es un proceso de desarrollo complejo, regulado por la interacción de diversas hormonas vegetales. Con el objetivo de profundizar en el mecanismo de regulación de estas rutas de señalización hormonal durante la germinación, nos centramos en el estudio del papel de proteín-fosfatasas tipo 2C (PP2Cs) de Arabidopsis. Utilizan...

The functional protein phosphatase type 2C from beechnut (Fagus sylvatica; FsPP2C1) was a negative regulator of abscisic acid (ABA) signaling in seeds. In this report, to get deeper insight on FsPP2C1 function, we aim to identify PP2C-interacting partners. Two closely related members (PYL8/RCAR3 and PYL7/RCAR2) of the Arabidopsis (Arabidopsis thali...

La biología de semillas es un área de gran relevancia dentro de la Fisiología Vegetal. Muchos de los procesos fisiológicos y moleculares que tienen lugar en las semillas, en especial los relacionados con la germinación, no están del todo aclarados. Existen evidencias directas de que el ácido abscísico (ABA) y el ácido jasmónico (JA) son dos de las...

Aislamiento y caracterización de factores transcripcionales relacionados con la germinación y su implicación en la señalización de ácido abscísico y óxido nítrico. La semilla necesita integrar en la célula las señales, tanto ambientales como hormonales, que la informan si las condiciones son apropiadas o no para germinar. Para ello, la célula debe...

Jasmonates are essential phytohormones for plant development and survival. However, the molecular details of their signalling pathway remain largely unknown. The identification more than a decade ago of COI1 as an F-box protein suggested the existence of a repressor of jasmonate responses that is targeted by the SCF(COI1) complex for proteasome deg...

FsPP2C2 was previously characterized in Fagus sylvatica L. seeds as a functional protein phosphatasetype-2C (PP2C). The expression of the FsPP2C2 gene is strongly upregulated by abscisic acid(ABA) in seeds and vegetative tissues. Since transgenic work is not feasible in Fagus, we have usedan overexpression approach in Arabidopsis (Arabidopsis thali...

FsPP2C1 is a functional protein phosphatase type-2C (PP2C) isolated from beech (Fagussylvatica L.) seeds. Previously, this gene was shown to be upregulated by abscisic acid (ABA)treatment and specifically expressed in ABA-treated seeds. It was demonstrated that constitutiveFsPP2C1 overexpression in Arabidopsis (Arabidopsis thaliana (L.) Heynh.) con...

Several gibberellic acid (GA3)-induced cDNA fragments encoding putative serine/threonine protein phosphatase (PP) 2A catalytic subunits were obtained by means of differential reverse transcriptase-PCR approach. The full-length clone, named FsPP2A1, isolated from a beechnut cDNA library, exhibited all the features of and homology to members of the P...

A functional abscisic acid (ABA)-induced protein phosphatase type 2C (PP2C) was previously isolated from beech (Fagus sylvatica) seeds (FsPP2C2). Because transgenic work is not possible in beech, in this study we overexpressed this gene in Arabidopsis (Arabidopsis thaliana) to provide genetic evidence on FsPP2C2 function in seed dormancy and other...

An abscisic acid (ABA)-induced cDNA fragment encoding a putative serine/threonine protein kinase (PK) was obtained by means of differential reverse transcriptase-polymerase chain reaction (RT-PCR). The full-length clone (FsPK4) was isolated from a cDNA library constructed using mRNA from ABA-treated Fagus sylvatica L. seeds. This clone contained th...

An enzymatically active recombinant protein kinase, previously isolated and characterized in Fagus sylvatica L. dormant seeds (FsPK1), was used to obtain a specific polyclonal antibody against this protein. Immunoblotting and immunohistochemical analysis of FsPK1 protein in beech seeds showed a strong immunostaining in the nucleus of the cells loca...

Many plant developmental and stress responses require the coordinated interaction of the jasmonate and other signalling pathways, such as those for ethylene, salicylic acid and abscisic acid. Recent research in Arabidopsis has uncovered several key players that regulate crosstalk between these signalling pathways and that shed light on the molecula...

In spite of the importance of jasmonates (JAs) as plant growth and stress regulators, the molecular components of their signaling pathway remain largely unknown. By means of a genetic screen that exploits the cross talk between ethylene (ET) and JAs, we describe the identification of several new loci involved in JA signaling and the characterizatio...