Biology subjects

Lopez-Gresa, M. P.

Publications and source records attributed to Lopez-Gresa, M. P..

5 recordsLinked to original sources

bioRxiv2023

Signaling mechanisms and agricultural applications of (Z)-3-Hexenyl Butyrate-mediated stomatal closure

Biotic and abiotic stresses can severely limit crop productivity. In response to drought, plants close stomata to prevent water loss. Besides, stomata are considered the main entrance of several pathogens. Therefore, the development of natural products to control stomata closure can be considered a sustainable strategy to cope with stresses in agriculture. Plants respond to different stresses by releasing volatile organic compounds (VOCs). Green leaf volatiles (GLVs), which are commonly produced across different plant species after tissue damage, comprise an important group within VOCs. Among them, (Z)-3-hexenyl butyrate (HB) was described as a natural inducer of stomatal closure, playing an important role in stomatal immunity, although its mechanism of action is still unknown. Here, through different genetic, pharmacological, and biochemical approaches, we uncover that HB perception initiates various defense signaling events such as activation of Ca2+ permeable channels, mitogen-activated protein kinases (MPKs) and production of NADPH oxidase-mediated reactive oxygen species (ROS). Furthermore, HB-mediated stomata closure resulted to be independent of abscisic acid (ABA) biosynthesis and signaling. Additionally, exogenous treatments with HB alleviate water stress and improve fruit productivity in tomato plants. The efficacy of HB was also tested under open field conditions, leading to enhanced resistance against Phytophthora spp. and Pseudomonas syringae infection in potato and tomato plants, respectively. Taken together, our results provide insights into HB signaling transduction pathway, confirming its role in stomatal closure and plant immune system activation, and proposing HB as a new phytoprotectant for the sustainable control of biotic and abiotic stresses in agriculture.

molecular biology↗

bioRxiv2023

Metabolic crosstalk between hydroxylated monoterpenes and salicylic acid in tomato defence response against Pseudomonas syringae pv tomato

Hydroxylated monoterpenes (HMTPs) are differentially emitted by tomato plants efficiently resisting a bacterial infection. We have studied the defensive role of these volatiles in the tomato response to bacteria, whose main entrance are stomata apertures. Treatments with some HMTPs resulted in stomatal closure and PR1 induction. Particularly, -terpineol induced stomatal closure in a salicylic (SA) and abscisic acid-independent manner, and conferred resistance to bacteria. Interestingly, transgenic tomato plants overexpressing or silencing the monoterpene synthase MTS1, which displayed alterations in the emission of HMTPs, exhibited changes in the stomatal aperture but not in plant resistance. Measures of both 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEcPP) and SA levels, revealed a competition for MEcPP by the methylerythritol phosphate (MEP) pathway and the SA biosynthesis activation, thus explaining the absence of phenotype in transgenic plants. These results were confirmed by chemical inhibition or activation of the MEP pathway. Besides, treatments with BTH, a SA functional analogue, conferred enhanced resistance in transgenic tomato plants overexpressing MTS1. Finally, plants overexpressing MTS1 induced PR1 and stomata closure in neighbouring plants. Our results confirm the role of HMTPs in both intra and inter-plant immune signalling, and reveal a metabolic crosstalk between the MEP and SA pathways in tomato plants. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=124 SRC="FIGDIR/small/539605v2_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@1048cddorg.highwire.dtl.DTLVardef@1bc1948org.highwire.dtl.DTLVardef@1ff0eaorg.highwire.dtl.DTLVardef@101c4fa_HPS_FORMAT_FIGEXP M_FIG Metabolic crosstalk between hydroxylated monoterpenes and salicylic acid in tomato defence response against Pseudomonas syringae pv tomato. Created with BioRender.com. C_FIG

plant biology↗

bioRxiv2022

Tomato geranylgeranyl diphosphate synthase isoform 1 specifically interacts with phytoene synthase isoform 3 to produce strigolactones in tomato roots.

O_LICarotenoids are photoprotectant pigments and precursors of the hormones abscisic acid (ABA) and strigolactones (SL). Carotenoids are produced in plastids from geranylgeranyl diphosphate (GGPP), which is diverted to the carotenoid pathway by phytoene synthase (PSY). In tomato (Solanum lycopersicum), 3 genes encode plastid-targeted GGPP synthases (SlG1 to 3) and 3 genes encode PSY isoforms (PSY1 to 3). C_LIO_LIHere we investigated the function of SlG1 by generating loss-of-function lines and combining their metabolic and physiological phenotypes with gene co-expression and co-immunoprecipitation analyses. C_LIO_LILeaves and fruits of slg1 lines showed a wild-type phenotype in terms of isoprenoid accumulation, photosynthesis and development. Consistently, SlG1 is co-expressed with PSY3 and other genes involved in the production of carotenoids and SL (but not ABA) only in roots. SlG1 was also found to physically interact with the root-specific PSY3 isoform (and not with PSY1 and PSY2). Root SL (but not ABA) levels were reduced in slg1 lines. C_LIO_LIOur results confirm a specific role of SlG1 in SL production in combination with PSY3. This role appears to be restricted to roots as slg1 plants do not exhibit the shoot phenotype displayed by other SL-deficient mutants. C_LI

plant biology↗

bioRxiv2022

SlS5H silencing reveals specific pathogen-triggered salicylic acid metabolism in tomato

The phytohormone salicylic acid (SA or 2-hydroxybenzoic acid) plays an important role in plant biotic and abiotic responses. Gentisic acid (GA or 2,5-Dihydroxybenzoic acid, 2,5-DHBA) is the product of the SA 5-hydroxylation which is catalysed by the S5H enzyme, also known as DMR6. GA has been described to accumulate at high levels in compatible plant-pathogen interactions such as tomato plants infected by Citrus Exocortis Viroid (CEVd), and to a much lesser extend upon Pseudomonas syringae DC3000 pv. tomato (Pst) infection. Here we describe the specific effect that tomato SlS5H impairment produces on both plant-pathogen interactions. The induction of SlS5H in tomato plants by different pathogens was corroborated by qRT-PCR and correlated with previously described 2,5-DHBA accumulations. Transient SlS5H over-expression assays in Nicotiana benthamiana confirmed that SA is a substrate for SlS5H in vivo. RNAi_SlS5H tomato transgenic plants were generated and characterized upon CEVd and Pst infections. Transgenic tomato plants displayed an activation of defences and therefore a loss of susceptibility against both pathogens, and alternative SA homeostasis seems to occur for each specific interaction. Metabolomic assays revealed that whilst the glycosylated form of SA was the most discriminant metabolite found in CEVd infected RNAi_SlS5H transgenic plants, trans-feruloyldopamine, feruloylquinic acid, feruloylgalactarate and 2-hydroxyglutarate were the most accumulated compounds in the Pst-infected transgenic tomato leaves. Transgenic lines also displayed hyper susceptibility to Botrytis cinerea, as well as a smaller size and early senescence. Collectively, our results reveal a novel mechanism by which tomato plants specifically set SA homeostasis upon different pathogen attacks. One sentence summaryThe impairment of SA hydroxylation in tomato plants uncovers specific SA homeostasis upon CEVd or Pseudomonas syringae infections.

biochemistry↗

bioRxiv2021

Custom-made design of metabolite composition in N. benthamiana leaves using CRISPR activators.

Transcriptional regulators based on CRISPR architecture expand our ability of reprogramming endogenous gene expression in plants. One of their potential applications is the customization of plant metabolome through the activation of selected enzymes in a given metabolic pathway. Using the previously described multiplexable CRISPR activator dCasEV2.1, we assayed the selective enrichment in Nicotiana benthamiana leaves of four different flavonoids, namely naringenin, eriodictyol, kaempferol and quercetin. After careful selection of target genes and guide RNAs combinations, we created successful activation programs for each of the four metabolites, each program activating between three and seven genes, and with individual gene activation levels ranging from 4- to 1500-fold. Metabolic analysis of the flavonoid profiles of each multigene activation program showed a sharp and selective enrichment of the intended metabolites and their glycosylated derivatives. Remarkably, principal component analysis of untargeted metabolic profiles clearly separated samples according to their activation treatment, and hierarchical clustering separated the samples in five groups, corresponding to the expected four highly enriched metabolite groups, plus an un-activated control. These results demonstrate that dCasEV2.1 is a powerful tool for re-routing metabolic fluxes towards the accumulation of metabolites of interest, opening the door for custom-made design of metabolic contents in plants.

synthetic biology↗