Antonio Encina

Universidad de León | UNILEON · Department of Engineering and Agricultural Sciences

The field of plant-microbe interactions mediated by Biogenic Volatile Organic Compounds (BVOCs) still faces several limitations due to the lack of reliable equipment. We present a novel device designed to evaluate in vitro plant-microbe volatile interactions, the plant-microbe VOC Chamber. It was tested by evaluating the effects exerted on wheat de...

You can find this article in The Conversation: "https://theconversation.com/plantas-quimera-arte-y-ciencia-de-los-injertos-175853"

Plant cell walls provide essential functions in cell recognition, differentiation, adhesion and wound responses. Therefore, it is tempting to hypothesize that cell walls play a key role in grafting, but to date there are no quantitative studies targeting on cell wall changes during grafting. The aim of this work was to investigate the dynamics of p...

The cell wall (CW) is a dynamic structure extensively remodeled during plant growth and under stress conditions, however little is known about its roles during the immune system priming, especially in crops. In order to shed light on such a process, we used the Phaseolus vulgaris-Pseudomonas syringae (Pph) pathosystem and the immune priming capacit...

Grafting is a widespread horticultural technique with applications in numerous crops due to its great advantages for yield and crop health. In tomato cultivation, this technique is well recognised and it has a huge economic impact. Nevertheless, this technique is limited by the occurrence of unfunctional grafts, which decreases the success rate and...

Cell walls provide essential functions in cell-cell recognition, cell differentiation, cell adhesion and wound responses. Therefore, it is likely to hypothesize that cell walls play a key role in grafting, a developmentally regulated process in which wound repairing, tissue adhesion, and vascular reconnection are major players. Despite this, not ma...

Grafting is a technique applied to a considerable number of crops, with tomato standing out. However, this technique is limited by the obtaining of unfunctional grafts, which decrease the success rate and therefore the benefits achieved. The aim of this work was to analyze the failure in intraspecific grafting of tomato plants, focusing on tissue d...

Background Besides the use of maize grain as food and feed, maize stover can be a profitable by-product for cellulosic ethanol production, whereas the whole plant can be used for silage production. However, yield is reduced by pest damages, stem corn borers being one of the most important yield constraints. Overall, cell wall composition is key in...

Lodging is one of the causes of maize (Zea mays L.) production losses worldwide and, at least, the resistance to stalk lodging has been positively correlated with stalk strength. In order to elucidate the putative relationship between cell wall, stalk strength and lodging resistance, twelve maize inbreds varying in rind penetration strength and lod...

Saxifraga paniculata is a subalpine succulent perennial plant arranged in a rosette that is usually found in shallow soil among limestone rocks. Stereoscopic, light and scanning electron microscopy were used to describe the anatomical structure of S. paniculata leaves, paying special attention to structures related to CaCO3 (calcium carbonate) rele...

Despite the importance of grafting in horticultural crops such as tomato (Solanum lycopersicum L.), the structural changes that occur during the graft establishment are little understood. Using histological techniques, the present work examines the time course of changes on the anatomical structure of the graft junction in functional tomato homogra...

Background: Besides the use of maize grain as food and feed, maize stover can be a profitable by-product for cellulosic ethanol production, whereas the whole plant can be used in silage production. However, yield is reduced by pest damages, where stem corn borers are one of the most important factors limiting yield. Overall, cell wall composition i...

Plant cell and organ cultures of Helianthella quinquenervis, a medicinal plant whose roots are used by the Tarahumara Indians of Chihuahua, Mexico, to relieve several ailments, were established to identify and quantify some chromenes with biological activity, such as encecalin, and to evaluate their potential for biotechnological production. Gas ch...

Class III plant peroxidases (Prxs) are involved in the oxidative polymerization of lignins. Zinnia elegans Jacq. Basic peroxidase (ZePrx) has been previously characterized as capable of catalyzing this reaction in vitro and the role in lignin biosynthesis of several of its Arabidopsis thaliana homologous has been previously confirmed. In the presen...

Background. Despite the importance of grafting in agriculture, particularly in horticultural crops such as tomato (Solanum lycopersicum L.), the structural changes that occur during the establishment of a graft are little understood. Using histochemical techniques, the present work examines the progression of the structure of the graft junction in...

Grafting is an ancient agronomic technique that involves cutting and joining two plants to form a new entire one. The graft part with the radicular system is called rootstock, and the other part is called scion. The use of grafting is crucial in some crop species yield, as grapevine, citrus, watermelon, eggplant, and specially tomato. The ability t...

The cellulose biosynthesis inhibitors, or CBIs, are of great importance because of their utility to study the structural plasticity of plant cell walls (Acebes et al., 2010). Among the CBIs, three groups have been defined, depending on their mechanism of action. Cobtorin has been placed in group three, with other compounds that interfere with the c...

The technique of cutting and joining different plants together is known as grafting. From an economical point of view, grafting is an important agronomic technology with different uses and a long history. The influence of the stock (plant providing the root system) in the scion (added piece of tissue from a different plant) or vice versa has been r...

This poster is a brief illustrated review of the plant cell wall components and structure and the possible biotchnological applications of them.

Main conclusion: Ancymidol inhibits the incorporation of cellulose into cell walls of maize cell cultures in a gibberellin-independent manner, impairing cell growth; the reduction in the cellulose content is compensated with xylans. Ancymidol is a plant growth retardant which impairs gibberellin biosynthesis. It has been reported to inhibit cellul...

Maize (Zea mays L.) suspension-cultured cells habituated to a cellulose biosynthesis inhibitor 2,6-dichlorobenzonitrile (DCB) have a modified cell wall, in which the reduction in the cellulose content is compensated by a network of highly cross-linked feruloylated arabinoxylans and the deposition of lignin-like polymers. For both arabinoxylan cross...

Mediterranean Corn Borer (MCB), Sesamia nonagrioides Lef, is an important pest of maize in temperate areas causing significant stalk lodging and yield losses. The main focus of the current study were to determine possible changes in chemical traits (phenols, flavonoids, anthocyanins, sugars, fibers, and lignin) during plant development after the fl...

As a consequence of the habituation to low levels of dichlobenil (DCB), cultured maize cells presented an altered hemicellulose cell fate with a lower proportion of strongly wall-bound hemicelluloses and an increase in soluble extracellular polymers released into the culture medium. The aim of this study was to investigate the relative molecular ma...

Litter quality is crucial for the exchange of carbon and nutrients between aboveground and belowground ecosystem compartments through its effect on litter decomposition. Although the effect of grazing on forest ecosystems has been investigated in various studies, the interactive effect that native ungulates and forest management can have on litter...

Caffeoyl Coenzyme A 3-O-Methyltransferase (CCoAOMT) and Caffeic acid-O-Methyltransferase (COMT) are key enzymes in the biosynthesis of coniferyl and sinapyl alcohols, the precursors of guaiacyl (G) and syringyl (S) lignin subunits. The function of these enzymes was characterised in single and double mutant maize plants. In this work, we determined...

Ancymidol (α-cyclopropyl-α-[4-methoxyphenyl]-5-pyrimidine-methanol) is a plant growth retardant whose primary mode of action is the inhibition of ent-kaurene oxidase activity, impairing the gibberellin (GA) biosynthesis [1]. Besides this well-known activity, ancymidol has been reported to inhibit the cellulose synthesis of BY-2 tobacco cells in a G...

The habituation of bean cells to quinclorac did not rely on cell wall modifications, contrary to what it was previously observed for the well-known cellulose biosynthesis inhibitors dichlobenil or isoxaben. The aim of the present study was to investigate whether or not the bean cells habituation to quinclorac is related to an enhancement of antioxi...

Cellulose biosynthesis inhibitors have been widely used to study several aspects of cell wall biology in the last years [1]. By stepwise habituation of maize suspension cultured cells to dichlobenil, a well-known inhibitor of cellulose biosynthesis, cellulose-deficient maize cells have been obtained in our laboratory. DCB-habituated cells have a mo...

Maize lodging represents a significant loss in grain yield. Several studies indicated that the physico-chemical properties of the secondary cell wall are key factors in determining the degree of stalk strength in different maize varieties. Secondary cell wall is a dynamic structure mainly composed of lignin, cellulose and hemicelluloses. However, t...

The cellulose biosynthesis inhibitor 2,6-diclorobenzonitrile (DCB) has been widely used to gain insights into cell wall composition and architecture. Studies of changes during early habituation to DCB can provide information on mechanisms that allow tolerance/habituation to DCB. In this context, maize cultured cells with a reduced amount of cellulo...

Coumarate 3-hydroxylase (C3H) catalyzes a key step of the synthesis of the two main lignin subunits, guaiacyl (G) and syringyl (S) in dicotyledonous species. As no functional data are available in regards to this enzyme in monocotyledonous species, we generated C3H1 knock-down maize plants. The results obtained indicate that C3H1 participates in li...

Maize (Zea mays L.) suspension-cultured cells with up to 70% less cellulose were obtained by stepwise habituation to dichlobenil (DCB), a cellulose biosynthesis inhibitor. Cellulose deficiency was accompanied by marked changes in cell wall matrix polysaccharides and phenolics as revealed by FTIR spectroscopy. Cell wall compositional analysis indica...

Cell-suspension cultures habituated to 2,6-dichlorobenzonitrile (DCB) survive with reduced cellulose owing to hemicellulose network modification. We aimed to define the hemicellulose metabolism modifications in DCB-habituated maize cells showing a mild reduction in cellulose at different stages in the culture cycle. Using pulse-chase radiolabelling...

Bean cells habituated to grow in the presence of dichlobenil exhibited reduced cellulose and hemicellulose content and an increase in pectic polysaccharides. Furthermore, following the extraction of pectins and hemicelluloses, a large amount of neutral sugars was released. These sugars were found to be part of a soluble β-1,4-glucan in a preliminar...

The variety of bioassays developed to evaluate different inhibition responses for cellulose biosynthesis inhibitors makes it difficult to compare the results obtained. This work aims (i) to test a single inhibitory assay for comparing active concentrations of a set of putative cellulose biosynthesis inhibitors and (ii) to characterize their effect...

The effect of water and nutrient availability on the performance of Scots pine (Pinus sylvestris L.) against Ophiostoma ips (Rumb.), a bark beetle-associated phytopathogenic blue-stain fungus, was investigated. Field-grown trees were subjected for 18 months to water-stress and/or fertilization, and the effects of such treatments on the needle nutri...

This monograph deals with a heterogeneous group of structurally unrelated compounds, called cellulose biosynthesis inhibitors (CBIs). This group includes dichlobenil, isoxaben, thaxtomin A, flupoxam, triazofenamide, compound 1, CGA 325-615 and AE F150944. Other putative CBIs that inhibit cellulose biosynthesis in a secondary effect, such as quinclo...

Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme involved in the last step of monolignol biosynthesis. The effect of CAD down-regulation on lignin production was investigated through a transgenic approach in maize. Transgenic CAD-RNAi plants show a different degree of enzymatic reduction depending on the analyzed tissue and show alterations in...

Fourier Transform InfraRed (FTIR) spectroscopy is a powerful and rapid technique for analysing cell wall components and putative cross-links, which is able to non-destructively recognize polymers and functional groups and provide abundant information about their in muro organization. FTIR spectroscopy has been reported to be a useful tool for monit...

The habituation of cell cultures to cellulose biosynthesis inhibitors such as dichlobenil (DCB) represents a valuable tool to improve our knowledge of the mechanisms involved in plant cell wall structural plasticity. Maize cell lines habituated to lethal concentrations of DCB were able to grow through the acquisition of a modified cell wall in whic...

Cellulose biosynthesis inhibitors, such as dichlobenil (DCB), have become a valuable tool for the analysis of structural and compositional plasticity of plant cell walls. By stepwise increasing the concentration of DCB in the culture medium, we obtained maize cells able to cope with DCB through the acquisition of a modified cell wall in which cellu...

Few regulators of phenylpropanoids have been identified in monocots having potential as biofuel crops. Here we demonstrate the role of the maize (Zea mays) R2R3-MYB factor ZmMYB31 in the control of the phenylpropanoid pathway. We determined its in vitro consensus DNA-binding sequence as ACC(T)/(A) ACC, and chromatin immunoprecipitation (ChIP) estab...

Cultured maize cells habituated to grow in the presence of the cellulose synthesis inhibitor dichlobenil (DCB) have a modified cell wall in which the amounts of cellulose are reduced and the amounts of arabinoxylan increased. This paper examines the contribution of cell wall-esterified hydroxycinnamates to the mechanism of DCB habituation. For this...

The biochemical and molecular processes involved in the habituation of maize cells to growth in the presence of the cellulose biosynthesis inhibitor dichlobenil (DCB) were investigated. DCB affects the synthesis of cellulose both in active and stationary growth phases and alters the expression of several CesA genes. Of these, ZmCesA5 and ZmCesA7 se...

Bean cells that have been habituated to grow in a lethal concentration (12 μM) of 2,6-dichlorobenzonitrile (dichlobenil or DCB, a cellulose biosynthesis inhibitor) are known to have decreased cellulose content in their cell walls. Xyloglucan, which is bound to cellulose and together with it forms the main loading network of plant cell walls, has al...

Cellulose biosynthesis inhibitors (CBIs) form a heterogeneous group of structurally unrelated compounds that specifically affect the assembly or the deposition of cellulose. With the exception of thaxtomin A, the only naturally occurring CBI, all other CBIs are synthetic compounds. A number of them (dichlobenil, isoxaben and flupoxam) are used as h...

The habituation of cell cultures to cellulose biosynthesis inhibitors constitutes a valuable method for learning more about the plasticity of plant cell wall composition and structure. The subculture of habituated cells in the absence of an inhibitor (dehabituation) offers complementary information: some habituation-associated modifications revert,...

Few regulators of phenylpropanoids have been identified in monocots having potential as biofuel crops. Here we demonstrate the role of the maize (Zea mays) R2R3-MYB factor ZmMYB31 in the control of the phenylpropanoid pathway. We determined its in vitro consensus DNA-binding sequence as ACC T / A ACC, and chromatin immunoprecipitation (ChIP) establ...

Suspension-cultured bean cells habituated to growth in a lethal concentration of dichlobenil were cultured for 3-5 years in a medium lacking the inhibitor in order to obtain long-term dehabituated cell lines. The growth parameters, cell morphology and ultrastructure of cells in the absence of dichlobenil reverted to that of non-habituated cells. Th...

The involvement of the maize ZmMYB42 R2R3-MYB factor in the phenylpropanoid pathway and cell wall structure and composition was investigated by overexpression in Arabidopsis thaliana. ZmMYB42 down-regulates several genes of the lignin pathway and this effect reduces the lignin content in all lignified tissues. In addition, ZmMYB42 plants generate a...

Growth of maize (Zea mays L.) callus-culture cells was inhibited using dichlobenil (2,6 dichlorobenzonitrile, DCB) concentrations ≥1 μM; I 50 value for the effect on inhibited fresh weight gain was 1.5 μM. By increasing the DCB concentration in the culture medium, DCB-habituated cells became 13 times more tolerant of the inhibitor (I 50: 20 μM). In...

In the present work we study the microscopic anatomy of three galls located on Pistacia terebinthus leaflets. The galls were induced by three species of gallicolous aphids: Paracletus cimiciformis, Forda marginata and Forda formicaria. With respect to the complex life cycle of these three species, the galls studied here represent sites in which a f...

The herbicide quinclorac has been reported to inhibit incorporation of glucose both into cellulose and other cell wall polysaccharides. However, further work has failed to detect any apparent effect of this herbicide on the synthesis of the wall. In order to elucidate whether quinclorac elicits the inhibition of cellulose biosynthesis directly, in...

The present work describes the structural characterization of Pistacia terebinthus leaflets, focusing on changes in structure during the maturation process. P. terebinthus leaflets are characterized by the presence of: (1) abundant crystals, mainly in mesophyll cells; (2) both unicellular and glandular tri- chomes; (3) a large amount of tannins; (4...