Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Current refinement(s):

Records 1 - 20 / 67

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: keywords==abscisic-acid
Check title to add to marked list
Ecological relevance of strigolactones in nutrient uptake and other abiotic stresses, and in plant-microbe interactions below ground
Andreo Jimenez, B. ; Ruyter-Spira, C.P. ; Bouwmeester, H.J. ; Lopez-Raez, J.A. - \ 2015
Plant and Soil 394 (2015)1. - ISSN 0032-079X - p. 1 - 19.
arbuscular mycorrhizal fungi - carotenoid cleavage dioxygenases - root-system architecture - phosphate starvation - medicago-truncatula - drought stress - abscisic-acid - analog gr24 - stomatal conductance - rhizobial infection
Background Plants are exposed to ever changing and often unfavourable environmental conditions, which cause both abiotic and biotic stresses. They have evolved sophisticated mechanisms to flexibly adapt themselves to these stress conditions. To achieve such adaptation, they need to control and coordinate physiological, developmental and defence responses. These responses are regulated through a complex network of interconnected signalling pathways, in which plant hormones play a key role. Strigolactones (SLs) are multifunctional molecules recently classified as a new class of phytohormones, playing a key role as modulators of the coordinated plant development in response to nutrient deficient conditions, especially phosphorus shortage. Belowground, besides regulating root architecture, they also act as molecular cues that help plants to communicate with their environment. Scope This review discusses current knowledge on the different roles of SLs below-ground, paying special attention to their involvement in phosphorus uptake by the plant by regulating root architecture and the establishment of mutualistic symbiosis with arbuscular mycorrhizal fungi. Their involvement in plant responses to other abiotic stresses such as drought and salinity, as well as in other plant-(micro)organisms interactions such as nodulation and root parasitic plants are also highlighted. Finally, the agronomical implications of SLs below-ground and their potential use in sustainable agriculture are addressed. Conclusions Experimental evidence illustrates the biological and ecological importance of SLs in the rhizosphere. Their multifunctional nature opens up a wide range of possibilities for potential applications in agriculture. However, a more in-depth understanding on the SL functioning/signalling mechanisms is required to allow us to exploit their full potential.
Combined biotic and abiotic stress resistance in tomato
Kissoudis, C. ; Chowdhury, R. ; Heusden, A.W. van; Wiel, C.C.M. van de; Finkers, H.J. ; Visser, R.G.F. ; Bai, Y. ; Linden, C.G. van der - \ 2015
Euphytica 202 (2015)2. - ISSN 0014-2336 - p. 317 - 332.
salt tolerance - oidium-neolycopersici - salinity tolerance - botrytis-cinerea - powdery mildew - abscisic-acid - plant-disease - phenotypic plasticity - solanum-lycopersicon - climate-change
Abiotic and biotic stress factors are the major constrains for the realization of crop yield potential. As climate change progresses, the spread and intensity of abiotic as well as biotic stressors is expected to increase, with increased probability of crops being exposed to both types of stress. Shielding crops from combinatorial stress requires a better understanding of the plant’s response and its genetic architecture. In this study, we evaluated resistance to salt stress, powdery mildew and to both stresses combined in tomato, using the Solanum habrochaites LYC4 introgression line (IL) population. The IL population segregated for both salt stress tolerance and powdery mildew resistance. Using SNP array marker data, QTLs were identified for salt tolerance as well as Na+ and Cl- accumulation. Salt stress increased the susceptibility of the population to powdery mildew in an additive manner. Phenotypic variation for disease resistance was reduced under combined stress as indicated by the coefficient of variation. No correlation was found between disease resistance and Na+ and Cl- accumulation under combined stress Most genetic loci were specific for either salt stress tolerance or powdery mildew resistance. These findings increase our understanding of the genetic regulation of responses to abiotic and biotic stress combinations and can provide leads to more efficiently breeding tomatoes and other crops with a high level of disease resistance while maintaining their performance in combination with abiotic stress.
Fruit illumination stimulates cell division but has no detectable effect on fruit size in tomato (Solanum lycopersicum)
Okello, R.C. ; Heuvelink, E. ; Visser, P.H.B. de; Lammers, M. ; Maagd, R.A. de; Marcelis, L.F.M. ; Struik, P.C. - \ 2015
Physiologia Plantarum 154 (2015)1. - ISSN 0031-9317 - p. 114 - 127.
arabidopsis-thaliana - elongation growth - plant development - seed development - sink metabolism - cucumber fruits - gene-expression - hormone-levels - abscisic-acid - phytochrome-b
Light affects plant growth through assimilate availability and signals regulating development. The effects of light on growth of tomato fruit were studied using cuvettes with light-emitting diodes providing white, red or blue light to individual tomato trusses for different periods during daytime. Hypotheses tested were as follows: (1) light-grown fruits have stronger assimilate sinks than dark-grown fruits, and (2) responses depend on light treatment provided, and fruit development stage. Seven light treatments [dark, 12-h white, 24-h white, 24-h red and 24-h blue light, dark in the first 24 days after anthesis (DAA) followed by 24-h white light until breaker stage, and its reverse] were applied. Observations were made between anthesis and breaker stage at fruit, cell and gene levels. Fruit size and carbohydrate content did not respond to light treatments while cell division was strongly stimulated at the expense of cell expansion by light. The effects of light on cell number and volume were independent of the combination of light color and intensity. Increased cell division and decreased cell volume when fruits were grown in the presence of light were not clearly corroborated by the expression pattern of promoters and inhibitors of cell division and expansion analyzed in this study, implying a strong effect of posttranscriptional regulation. Results suggest the existence of a complex homeostatic regulatory system for fruit growth in which reduced cell division is compensated by enhanced cell expansion.
Enhancing crop resilience to combined abiotic and biotic stress through the dissection of physiological and molecular crosstalk
Kissoudis, C. ; Wiel, C.C.M. van de; Visser, R.G.F. ; Linden, C.G. van der - \ 2014
Frontiers in Plant Science 5 (2014). - ISSN 1664-462X - 20 p.
systemic acquired-resistance - activated protein-kinase - programmed cell-death - regulated gene-expression - plant immune-responses - abscisic-acid - salicylic-acid - disease resistance - arabidopsis-thaliana - transcription factor
Plants growing in their natural habitats are often challenged simultaneously by multiple stress factors, both abiotic and biotic. Research has so far been limited to responses to individual stresses, and understanding of adaptation to combinatorial stress is limited, but indicative of non-additive interactions. Omics data analysis and functional characterization of individual genes has revealed a convergence of signaling pathways for abiotic and biotic stress adaptation. Taking into account that most data originate from imposition of individual stress factors, this review summarizes these findings in a physiological context, following the pathogenesis timeline and highlighting potential differential interactions occurring between abiotic and biotic stress signaling across the different cellular compartments and at the whole plant level. Potential effects of abiotic stress on resistance components such as extracellular receptor proteins, R-genes and systemic acquired resistance will be elaborated, as well as crosstalk at the levels of hormone, reactive oxygen species, and redox signaling. Breeding targets and strategies are proposed focusing on either manipulation and deployment of individual common regulators such as transcription factors or pyramiding of non- (negatively) interacting components such as R-genes with abiotic stress resistance genes. We propose that dissection of broad spectrum stress tolerance conferred by priming chemicals may provide an insight on stress cross regulation and additional candidate genes for improving crop performance under combined stress. Validation of the proposed strategies in lab and field experiments is a first step toward the goal of achieving tolerance to combinatorial stress in crops.
REDUCED DORMANCY5 Encodes a Protein Phosphatase 2C That Is Required for Seed Dormancy in Arabidopsis
Xiang, Y. ; Nakabayashi, K. ; Ding, J. ; He, F. ; Bentsink, L. ; Soppe, W.J.J. - \ 2014
The Plant Cell 26 (2014)11. - ISSN 1040-4651 - p. 4362 - 4375.
rna-binding proteins - abscisic-acid - messenger-rna - pp2c phosphatases - germination - thaliana - aba - reveals - gene - mutants
Seed dormancy determines germination timing and contributes to crop production and the adaptation of natural populations to their environment. Our knowledge about its regulation is limited. In a mutagenesis screen of a highly dormant Arabidopsis thaliana line, the reduced dormancy5 (rdo5) mutant was isolated based on its strongly reduced seed dormancy. Cloning of RDO5 showed that it encodes a PP2C phosphatase. Several PP2C phosphatases belonging to clade A are involved in abscisic acid signaling and control seed dormancy. However, RDO5 does not cluster with clade A phosphatases, and abscisic acid levels and sensitivity are unaltered in the rdo5 mutant. RDO5 transcript could only be detected in seeds and was most abundant in dry seeds. RDO5 was found in cells throughout the embryo and is located in the nucleus. A transcriptome analysis revealed that several genes belonging to the conserved PUF family of RNA binding proteins, in particular Arabidopsis PUMILIO9 (APUM9) and APUM11, showed strongly enhanced transcript levels in rdo5 during seed imbibition. Further transgenic analyses indicated that APUM9 reduces seed dormancy. Interestingly, reduction of APUM transcripts by RNA interference complemented the reduced dormancy phenotype of rdo5, indicating that RDO5 functions by suppressing APUM transcript levels.
Stomatal malfunctioning under low VPD conditions: induced by alterations in stomatal morphology and leaf anatomy or in the ABA signaling?
Ali Niaei Fard, S. ; Malcolm Matamoros, P. ; Meeteren, U. van - \ 2014
Physiologia Plantarum 152 (2014)4. - ISSN 0031-9317 - p. 688 - 699.
relative-air-humidity - abscisic-acid - tradescantia-virginiana - water-loss - in-vitro - response characteristics - carbon-dioxide - growth - plants - arabidopsis
Exposing plants to low VPD reduces leaf capacity to maintain adequate water status thereafter. To find the impact of VPD on functioning of stomata, stomatal morphology and leaf anatomy, fava bean plants were grown at low (L, 0.23 kPa) or moderate (M, 1.17 kPa) VPDs and some plants that developed their leaves at moderate VPD were then transferred for 4 days to low VPD (M[RIGHTWARDS ARROW]L). Part of the M[RIGHTWARDS ARROW]L-plants were sprayed with ABA (abscisic acid) during exposure to L. L-plants showed bigger stomata, larger pore area, thinner leaves and less spongy cells compared with M-plants. Stomatal morphology (except aperture) and leaf anatomy of the M[RIGHTWARDS ARROW]L-plants were almost similar to the M-plants, while their transpiration rate and stomatal conductance were identical to that of L-plants. The stomatal response to ABA was lost in L-plants, but also after 1-day exposure of M-plants to low VPD. The level of foliar ABA sharply decreased within 1-day exposure to L, while the level of ABA-GE (ABA-glucose ester) was not affected. Spraying ABA during the exposure to L prevented loss of stomatal closing response thereafter. The effect of low VPD was largely depending on exposure time: the stomatal responsiveness to ABA was lost after 1-day exposure to low VPD, while the responsiveness to desiccation was gradually lost during 4-day exposure to low VPD. Leaf anatomical and stomatal morphological alterations due to low VPD were not the main cause of loss of stomatal closure response to closing stimuli.
Natural variation in stomatal response to closing stimuli among Arabidopsis thaliana accessions after exposure to lowe VPD as a tool to recognize the mechanism of disturbed stomatal functioning
Ali Niaei Fard, S. ; Meeteren, U. van - \ 2014
Journal of Experimental Botany 65 (2014)22. - ISSN 0022-0957 - p. 6529 - 6542.
relative-air-humidity - vapor-pressure-deficit - abscisic-acid - tradescantia-virginiana - genetic-variation - corylus-maxima - water status - guard-cells - plants - drought
Stomatal responses to closing stimuli are disturbed after long-term exposure of plants to low vapour pressure deficit (VPD). The mechanism behind this disturbance is not fully understood. Genetic variation between naturally occurring ecotypes can be helpful to elucidate the mechanism controlling stomatal movements in different environments. We characterized the stomatal responses of 41 natural accessions of Arabidopsis thaliana to closing stimuli (ABA and desiccation) after they had been exposed for 4 days to moderate VPD (1.17 kPa) or low VPD (0.23 kPa). A fast screening system was used to test stomatal response to ABA using chlorophyll fluorescence imaging under low O2 concentrations of leaf discs floating on ABA solutions. In all accessions stomatal conductance (gs) was increased after prior exposure to low VPD. After exposure to low VPD, stomata of 39 out of 41 of the accessions showed a diminished ABA closing response; only stomata of low VPD-exposed Map-42 and C24 were as responsive to ABA as moderate VPD-exposed plants. In response to desiccation, most of the accessions showed a normal stomata closing response following low VPD exposure. Only low VPD-exposed Cvi-0 and Rrs-7 showed significantly less stomatal closure compared with moderate VPD-exposed plants. Using principle component analysis (PCA), accessions could be categorized to very sensitive, moderately sensitive, and less sensitive to closing stimuli. In conclusion, we present evidence for different stomatal responses to closing stimuli after long-term exposure to low VPD across Arabidopsis accessions. The variation can be a useful tool for finding the mechanism of stomatal malfunctioning.
Transcriptional control of fleshy fruit development and ripening
Karlova, R.B. ; Chapman, N. ; David, K. ; Angenent, G.C. ; Seymour, G.B. ; Maagd, R.A. de - \ 2014
Journal of Experimental Botany 65 (2014)16. - ISSN 0022-0957 - p. 4527 - 4541.
mads-box gene - tomato fruit - abscisic-acid - draft genome - carotenoid accumulation - climacteric fruit - down-regulation - anthocyanin accumulation - ethylene biosynthesis - hormonal-regulation
Fleshy fruits have evolved to be attractive to frugivores in order to enhance seed dispersal, and have become an indispensable part of the human diet. Here we review the recent advances in the understanding of transcriptional regulation of fleshy fruit development and ripening with a focus on tomato. While aspects of fruit development are probably conserved throughout the angiosperms, including the model plant Arabidopsis thaliana, it is shown that the likely orthologues of Arabidopsis genes have distinct functions in fleshy fruits. The model for the study of fleshy fruit development is tomato, because of the availability of single gene mutants and transgenic knock-down lines. In other species, our knowledge is often incomplete or absent. Tomato fruit size and shape are co-determined by transcription factors acting during formation of the ovary. Other transcription factors play a role in fruit chloroplast formation, and upon ripening impact quality aspects such as secondary metabolite content. In tomato, the transcription factors NON-RIPENING (NOR), COLORLESS NON-RIPENING (CNR), and RIPENING INHIBITOR (MADS-RIN) in concert with ethylene signalling regulate ripening, possibly in response to a developmental switch. Additional components include TOMATO AGAMOUS-LIKE1 (TAGL1), APETALA2a (AP2a), and FRUITFULL (FUL1 and FUL2). The links between this highly connected regulatory network and downstream effectors modulating colour, texture, and flavour are still relatively poorly understood. Intertwined with this network is post-transcriptional regulation by fruit-expressed micro-RNAs targeting several of these transcription factors. This important developmental process is also governed by changes in DNA methylation levels and possibly chromatin remodelling.
Genetics and molecular mechanisms of resistance to powdery mildews in tomato (Solanum lycopersicum) and its wild relatives
Seifi Abdolabad, A.R. ; Dongli Gao, Dongli ; Zheng, Z. ; Pavan, S.N.C. ; Faino, L. ; Visser, R.G.F. ; Wolters, A.M.A. ; Bai, Y. - \ 2014
European Journal of Plant Pathology 138 (2014)3. - ISSN 0929-1873 - p. 641 - 665.
plant-pathogen interactions - hypersensitive cell-death - rna silencing suppressors - multiple fungal pathogens - race-specific resistance - leucine-rich repeat - oidium-neolycopersici - disease resistance - abscisic-acid - salicylic-acid
Powdery mildews (PMs) cause disease in a wide range of plant species including important crops. Taking tomato as an example, here we review findings on the genetic basis and mechanisms of plant resistance to PMs. First, we present a summary of our research on tomato resistance to two PM species, with the focus on Oidium neolycopersici. We discuss the genetics of resistance to this pathogen in tomato. Then, we compare different forms of resistance mediated by different resistance genes based on molecular and cytological data. Also, we provide a comparison between these resistance genes in tomato with those in barley, Arabidopsis and wheat, in order to present a model for the genetic basis of resistance to PMs in plants. We try to accommodate these resistance mechanisms in the current model of plant innate immunity. At the end we discuss possibilities to translate these findings to practical approaches in breeding for resistance to PMs in crops.
Delay of Iris flower senescence by cytokinins and jasmonates
Doorn, W.G. van; Celikel, F.G. ; Pak, C. ; Harkema, H. - \ 2013
Physiologia Plantarum 148 (2013)1. - ISSN 0031-9317 - p. 105 - 120.
cut carnation flowers - dependent protein-kinase - abscisic-acid - leaf senescence - gene-expression - ethylene biosynthesis - endogenous ethylene - plant senescence - petal senescence - nitric-oxide
It is not known whether tepal senescence in Iris flowers is regulated by hormones. We applied hormones and hormone inhibitors to cut flowers and isolated tepals of Iris x hollandica cv. Blue Magic. Treatments with ethylene or ethylene antagonists indicated lack of ethylene involvement. Auxins or auxin inhibitors also did not change the time to senescence. Abscisic acid (ABA) hastened senescence, but an inhibitor of ABA synthesis (norflurazon) had no effect. Gibberellic acid (GA3) slightly delayed senescence in some experiments, but in other experiments it was without effect, and gibberellin inhibitors [ancymidol or 4-hydroxy-5-isopropyl-2-methylphenyltrimethyl ammonium chloride-1-piperidine carboxylate (AMO-1618)] were ineffective as well. Salicylic acid (SA) also had no effect. Ethylene, auxins, GA3 and SA affected flower opening, therefore did reach the flower cells. Jasmonates delayed senescence by about 2.0 days. Similarly, cytokinins delayed senescence by about 1.52.0 days. Antagonists of the phosphatidylinositol signal transduction pathway (lithium), calcium channels (niguldipine and verapamil), calmodulin action [fluphenazine, trifluoroperazine, phenoxybenzamide and N-(6-aminohexyl)-5-chloro-1-naphtalenesulfonamide hydrochloride (W-7)] or protein kinase activity [1-(5-isoquinolinesulfonyl)-2-methylpiperazine hydrochloride (H-7), N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide hydrochloride (H-8) and N-(2-aminoethyl)-5-isoquinolinesulfonamide dihydrochloride (H-9)] had no effect on senescence, indicating no role of a few common signal transduction pathways relating to hormone effects on senescence. The results indicate that tepal senescence in Iris cv. Blue Magic is not regulated by endogenous ethylene, auxin, gibberellins or SA. A role of ABA can at present not be excluded. The data suggest the hypothesis that cytokinins and jasmonates are among the natural regulators.
Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs
Denance, N. ; Sanchez Vallet, A. ; Goffner, D. ; Molina, A. - \ 2013
Frontiers in Plant Science 4 (2013). - ISSN 1664-462X
systemic acquired-resistance - pattern-recognition receptors - mediated defense responses - syringae pv. tomato - abscisic-acid - pseudomonas-syringae - salicylic-acid - arabidopsis-thaliana - botrytis-cinerea - ustilago-maydis
Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid, and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokinins, gibberellins, and brassinosteroids, that have been thoroughly described to regulate plant development and growth, have recently emerged as key regulators of plant immunity. Plant hormones interact in complex networks to balance the response to developmental and environmental cues and thus limiting defense-associated fitness costs. The molecular mechanisms that govern these hormonal networks are largely unknown. Moreover, hormone signaling pathways are targeted by pathogens to disturb and evade plant defense responses. In this review, we address novel insights on the regulatory roles of the ABA, SA, and auxin in plant resistance to pathogens and we describe the complex interactions among their signal transduction pathways. The strategies developed by pathogens to evade hormone-mediated defensive responses are also described. Based on these data we discuss how hormone signaling could be manipulated to improve the resistance of crops to pathogens.
Transcriptional dynamics of two seed compartments with opposing roles in Arabidopsis seed germination
Dekkers, S.J.W. ; Pearce, S. ; Bolderen-Veldkamp, R.P. ; Marshall, A. ; Widera, P. ; Gilbert, J. ; Drost, H.G. ; Bassel, G. ; Muller, K. ; King, J.R. ; Wood, A. ; Grosse, I. ; Bentsink, L. - \ 2013
Plant Physiology 163 (2013)1. - ISSN 0032-0889 - p. 205 - 215.
thaliana seeds - abscisic-acid - leaf senescence - gene activity - endosperm - reveals - dormancy - metabolism - embryo - touch
Seed germination is a critical stage in the plant life cycle and the first step toward successful plant establishment. Therefore, understanding germination is of important ecological and agronomical relevance. Previous research revealed that different seed compartments (testa, endosperm, and embryo) control germination, but little is known about the underlying spatial and temporal transcriptome changes that lead to seed germination. We analyzed genome-wide expression in germinating Arabidopsis (Arabidopsis thaliana) seeds with both temporal and spatial detail and provide Web-accessible visualizations of the data reported (vseed.nottingham.ac.uk). We show the potential of this high-resolution data set for the construction of meaningful coexpression networks, which provide insight into the genetic control of germination. The data set reveals two transcriptional phases during germination that are separated by testa rupture. The first phase is marked by large transcriptome changes as the seed switches from a dry, quiescent state to a hydrated and active state. At the end of this first transcriptional phase, the number of differentially expressed genes between consecutive time points drops. This increases again at testa rupture, the start of the second transcriptional phase. Transcriptome data indicate a role for mechano-induced signaling at this stage and subsequently highlight the fates of the endosperm and radicle: senescence and growth, respectively. Finally, using a phylotranscriptomic approach, we show that expression levels of evolutionarily young genes drop during the first transcriptional phase and increase during the second phase. Evolutionarily old genes show an opposite pattern, suggesting a more conserved transcriptome prior to the completion of germination.
A comprehensive analysis of the physiological and anatomical components involved in higher water loss rates after leaf development at high humidity
Fanourakis, D. ; Heuvelink, E. ; Pinto De Carvalho, S.M. - \ 2013
Journal of Plant Physiology 170 (2013)10. - ISSN 0176-1617 - p. 890 - 898.
relative-air-humidity - stomatal response characteristics - abscisic-acid - gas-exchange - postharvest characteristics - tradescantia-virginiana - carbon-dioxide - rose cultivars - in-vitro - growth
To better understand the poor regulation of water loss after leaf development at high relative air humidity (RH), the relative importance of the physiological and anatomical components was analyzed focusing on cultivars with a contrasting sensitivity to elevated RH. The stomatal responsiveness to three closing stimuli (desiccation, abscisic acid feeding, light/dark transition), as well as several stomatal features (density, index, size and pore dimensions) and the cuticular transpiration rate (CTR) were determined in four rose cultivars, grown under moderate (60%) and high (95%) RH. Moreover, the effects of changes in stomatal density and pore dimensions on the stomatal conductance (gs) were quantified using a modified version of the Brown and Escombe equation. Higher water loss, as a result of plant growth at high RH, was primarily caused by an increase in residual gs, and to a lesser extent due to higher CTR. It was estimated that in leaflets subjected to desiccation the enhanced gs in high RH- as compared to moderate RH-grown plants was mostly due to poor stomatal functionality and to a lesser extent the combined result of higher stomatal density and longer pore length. It is concluded that the reduced degree and, specially, the reduced rate of stomatal closure are the primary causes of the large genotypic variation in the control of water loss in high RH-grown plants. Furthermore, it was found that although changes in stomatal length have no influence on stomatal functionality, changed anatomical features per se represent a significant and direct contribution to the increased water loss.
Long distance root-shoot signalling in plant-insect community interactions
Soler, R. ; Erb, M. ; Kaplan, I. - \ 2013
Trends in Plant Science 18 (2013)3. - ISSN 1360-1385 - p. 149 - 156.
below-ground herbivory - systemic acquired-resistance - indirect interaction webs - abscisic-acid - multitrophic interactions - interspecific interactions - mediated interactions - feeding insects - phytophagous insects - galling aphids
Plants mediate interactions between insects, including leaf- and root-feeders; yet the underlying mechanisms and connection with ecological theory remain unresolved. In this review, based on novel insights into long-distance (i.e., leaf-leaf, root-shoot) defence signalling, we explore the role of phytohormones in driving broad-scale patterns of aboveground-belowground interactions that can be extrapolated to general plant-insect relationships. We propose that the outcome of intra-feeding guild interactions is generally negative due to induction of similar phytohormonal pathways, whereas between-guild interactions are often positive due to negative signal crosstalk. However, not all outcomes could be explained by feeding guild; we argue that future studies should target ecologically representative plant-insect systems, distinguish subguilds, and include plant growth hormones to improve our understanding of plant-mediated interactions.
Beneficial microbes in a changing environment: are they always helping plants to deal with insects?
Pineda, A. ; Dicke, M. ; Pieterse, C.M.J. ; Pozo, M.J. - \ 2013
Functional Ecology 27 (2013)3. - ISSN 0269-8463 - p. 574 - 586.
arbuscular mycorrhizal symbiosis - ultraviolet-b radiation - abscisic-acid - climate-change - induced resistance - defense responses - water-stress - signaling pathways - fungal endophyte - salicylic-acid
Plants have a complex immune system that defends them against attackers (e.g. herbivores and microbial pathogens) but that also regulates the interactions with mutualistic organisms (e.g. mycorrhizal fungi and plant growth-promoting rhizobacteria). Plants have to respond to multiple environmental challenges, so they need to integrate both signals associated with biotic and abiotic stresses in the most appropriate response to survive. Beneficial microbes such as rhizobacteria and mycorrhizal fungi can help plants to deal' with pathogens and herbivorous insects as well as to tolerate abiotic stress. Therefore, beneficial microbes may play an important role in a changing environment, where abiotic and biotic stresses on plants are expected to increase. The effects of beneficial microbes on herbivores are highly context-dependent, but little is known on what is driving such dependency. Recent evidence shows that abiotic stresses such as changes in soil nutrients, drought and salt stress, as well as ozone can modify the outcome of plantmicrobeinsect interactions. Here, we review how abiotic stress can affect plantmicrobe, plantinsect and plantmicrobeinsect interactions, and the role of the network of plant signal-transduction pathways in regulating such interactions. Most of the studies on the effects of abiotic stress on plantmicrobeinsect interactions show that the effects of microbes on herbivores (positive or negative) are strengthened under stressful conditions. We propose that, at least in part, this is due to the crosstalk of the different plant signalling pathways triggered by each stress individually. By understanding the cross-regulation mechanisms we may be able to predict the possible outcomes of plant-microbeinsect interactions under particular abiotic stress conditions. We also propose that microbes can help plants to deal with insects mainly under conditions that compromise efficient activation of plant defences. In the context of global change, it is crucial to understand how abiotic stresses will affect species interactions, especially those interactions that are beneficial for plants. The final aim of this review is to stimulate studies unravelling when these beneficial' microbes really benefit a plant.
Rhizobacteria modify plant–aphid interactions: a case of induced systemic susceptibility
Pineda, A. ; Zheng, S.J. ; Loon, J.J.A. van; Dicke, M. - \ 2012
Plant Biology 14 (2012)Suppl. s1. - ISSN 1435-8603 - p. 83 - 90.
gene-expression - arabidopsis-thaliana - brevicoryne-brassicae - signaling pathways - induced resistance - insect herbivores - abscisic-acid - disease resistance - defense responses - myzus-persicae
Beneficial microbes, such as plant growth-promoting rhizobacteria and mycorrhizal fungi, may have a plant-mediated effect on insects aboveground. The plant growth-promoting rhizobacterium Pseudomonas fluorescens can induce systemic resistance in Arabidopsis thaliana against several microbial pathogens and chewing insects. However, the plant-mediated effect of these beneficial microbes on phloem-feeding insects is not well understood. Using Arabidopsis as a model, we here report that P. fluorescens has a positive effect on the performance (weight gain and intrinsic rate of increase) of the generalist aphid Myzus persicae, while no effect was recorded on the crucifer specialist aphid Brevicoryne brassicae. Additionally, transcriptional analyses of selected marker genes revealed that in the plant–microbe interaction with M. persicae, rhizobacteria (i) prime the plant for enhanced expression of LOX2, a gene involved in the jasmonic acid (JA)-regulated defence pathway, and (ii) suppress the expression of ABA1, a gene involved in the abscisic acid (ABA) signalling pathway, at several time points. In contrast, almost no effect of the plant–microbe interaction with B. brassicae was found at the transcriptional level. This study presents the first data on rhizobacteria-induced systemic susceptibility to an herbivorous insect, supporting the pattern proposed for other belowground beneficial microbes and aboveground phloem feeders. Moreover, we provide further evidence that at the transcript level, soil-borne microbes modify plant–aphid interactions.
Function of the HD-Zip I gene Oshox22 in ABA-mediated drought and salt tolerances in rice
Zhang, S. ; Kohlen, W. ; Jiang, L. ; Bouwmeester, H.J. ; Meijer, A.H. ; Schluepmann, H. ; Liu, C.M. ; Ouwerkerk, P.B.F. - \ 2012
Plant Molecular Biology 80 (2012)6. - ISSN 0167-4412 - p. 571 - 585.
plant craterostigma-plantagineum - acid signal-transduction - length cdna microarray - high-salinity stresses - abscisic-acid - transcription factor - homeobox gene - water-deficit - arabidopsis-thaliana - dna-binding
Oshox22 belongs to the homeodomain-leucine zipper (HD-Zip) family I of transcription factors, most of which have unknown functions. Here we show that the expression of Oshox22 is strongly induced by salt stress, abscisic acid (ABA), and polyethylene glycol treatment (PEG), and weakly by cold stress. Trans-activation assays in yeast and transient expression analyses in rice protoplasts demonstrated that Oshox22 is able to bind the CAAT(G/C)ATTG element and acts as a transcriptional activator that requires both the HD and Zip domains. Rice plants homozygous for a T-DNA insertion in the promoter region of Oshox22 showed reduced Oshox22 expression and ABA content, decreased sensitivity to ABA, and enhanced tolerance to drought and salt stresses at the seedling stage. In contrast, transgenic rice over-expressing Oshox22 showed increased sensitivity to ABA, increased ABA content, and decreased drought and salt tolerances. Based on these results, we conclude that Oshox22 affects ABA biosynthesis and regulates drought and salt responses through ABA-mediated signal transduction pathways.
Distinct cell wall architectures in seed endosperms in representatives of the brassicaceae and solanaceae
Lee, K.J.D. ; Dekkers, S.J.W. ; Steinbercher, T. ; Walsh, C.T. ; Bacic, T. ; Bentsink, L. ; Leubner-Metzger, G. ; Knox, J.P. - \ 2012
Plant Physiology 160 (2012)3. - ISSN 0032-0889 - p. 1551 - 1566.
cellulose synthase-like - hydroxyproline-rich glycoprotein - arabidopsis-thaliana - abscisic-acid - lepidium-sativum - micropylar endosperm - monoclonal-antibody - elongation growth - hydroxyl radicals - mannanase activity
In some species, a crucial role has been demonstrated for the seed endosperm during germination. The endosperm has been shown to integrate environmental cues with hormonal networks that underpin dormancy and seed germination, a process that involves the action of cell wall remodeling enzymes (CWREs). Here, we examine the cell wall architectures of the endosperms of two related Brassicaceae, Arabidopsis (Arabidopsis thaliana) and the close relative Lepidium (Lepidium sativum), and that of the Solanaceous species, tobacco (Nicotiana tabacum). The Brassicaceae species have a similar cell wall architecture that is rich in pectic homogalacturonan, arabinan, and xyloglucan. Distinctive features of the tobacco endosperm that are absent in the Brassicaceae representatives are major tissue asymmetries in cell wall structural components that reflect the future site of radicle emergence and abundant heteromannan. Cell wall architecture of the micropylar endosperm of tobacco seeds has structural components similar to those seen in Arabidopsis and Lepidium endosperms. In situ and biomechanical analyses were used to study changes in endosperms during seed germination and suggest a role for mannan degradation in tobacco. In the case of the Brassicaceae representatives, the structurally homogeneous cell walls of the endosperm can be acted on by spatially regulated CWRE expression. Genetic manipulations of cell wall components present in the Arabidopsis seed endosperm demonstrate the impact of cell wall architectural changes on germination kinetics.
Identification of Reference Genes For RT-qPCR Expression Analysis In Arabidopsis And Tomato Seeds
Dekkers, S.J.W. ; Willems, L.A.J. ; Bassel, G. ; Bolderen-Veldkamp, R.P. van; Ligterink, W. ; Hilhorst, H.W.M. ; Bentsink, L. - \ 2012
Plant and Cell Physiology 53 (2012)1. - ISSN 0032-0781 - p. 28 - 37.
quantitative pcr data - real-time pcr - gibberellin biosynthesis - housekeeping genes - low-temperature - messenger-rna - abscisic-acid - data sets - germination - normalization
Quantifying gene expression levels is an important research tool to understand biological systems. Reverse transcription–quantitative real-time PCR (RT–qPCR) is the preferred method for targeted gene expression measurements because of its sensitivity and reproducibility. However, normalization, necessary to correct for sample input and reverse transcriptase efficiency, is a crucial step to obtain reliable RT–qPCR results. Stably expressed genes (i.e. genes whose expression is not affected by the treatment or developmental stage under study) are indispensable for accurate normalization of RT–qPCR experiments. Lack of accurate normalization could affect the results and may lead to false conclusions. Since transcriptomes of seeds are different from other plant tissues, we aimed to identify reference genes specifically for RT–qPCR analyses in seeds of two important seed model species, i.e. Arabidopsis and tomato. We mined Arabidopsis seed microarray data to identify stably expressed genes and analyzed these together with putative reference genes from other sources. In total, the expression stability of 24 putative reference genes was validated by RT–qPCR in Arabidopsis seed samples. For tomato, we lacked transcriptome data sets of seeds and therefore we tested the tomato homologs of the reference genes found for Arabidopsis seeds. In conclusion, we identified 14 Arabidopsis and nine tomato reference genes. This provides a valuable resource for accurate normalization of gene expression experiments in seed research for two important seed model species.
A petunia ABC protein controls strigolactone-dependent symbiotic signalling and branching
Kretzschmar, T. ; Kohlen, W. ; Sasse, J. ; Borghi, L. ; Schlegel, M. ; Bachelier, J.B. ; Reinhardt, D. ; Bours, R.M.E.H. ; Bouwmeester, H.J. ; Martinoia, E. - \ 2012
Nature 483 (2012)7389. - ISSN 0028-0836 - p. 341 - 344.
arbuscular-mycorrhizal fungi - medicago-truncatula - auxin transport - abscisic-acid - gene family - arabidopsis - pcr - germination - inhibition - pathway
Strigolactones were originally identified as stimulators of the germination of root-parasitic weeds1 that pose a serious threat to resource-limited agriculture2. They are mostly exuded from roots and function as signalling compounds in the initiation of arbuscular mycorrhizae3, which are plant–fungus symbionts with a global effect on carbon and phosphate cycling4. Recently, strigolactones were established to be phytohormones that regulate plant shoot architecture by inhibiting the outgrowth of axillary buds5, 6. Despite their importance, it is not known how strigolactones are transported. ATP-binding cassette (ABC) transporters, however, are known to have functions in phytohormone translocation7, 8, 9. Here we show that the Petunia hybrida ABC transporter PDR1 has a key role in regulating the development of arbuscular mycorrhizae and axillary branches, by functioning as a cellular strigolactone exporter. P. hybrida pdr1 mutants are defective in strigolactone exudation from their roots, resulting in reduced symbiotic interactions. Above ground, pdr1 mutants have an enhanced branching phenotype, which is indicative of impaired strigolactone allocation. Overexpression of Petunia axillaris PDR1 in Arabidopsis thaliana results in increased tolerance to high concentrations of a synthetic strigolactone, consistent with increased export of strigolactones from the roots. PDR1 is the first known component in strigolactone transport, providing new opportunities for investigating and manipulating strigolactone-dependent processes.
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.