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 

Records 1 - 20 / 753

  • help
  • print

    Print search results

  • export
    A maximum of 250 titles can be exported. Please, refine your queryYou can also select and export up to 30 titles via your marked list.
  • alert
    We will mail you new results for this query: metisnummer==1014036
Check title to add to marked list
Insects for sustainable animal feed: inclusive business models involving smallholder farmers
Chia, Shaphan Y. ; Tanga, Chrysantus M. ; Loon, Joop J.A. van; Dicke, Marcel - \ 2019
Current Opinion in Environmental Sustainability 41 (2019). - ISSN 1877-3435 - p. 23 - 30.

Global population growth, an increasing demand for animal products and scarcity of conventional feed ingredients drive the search for alternative protein sources for animal feed. Extensive research indicates that insects provide good opportunities as a sustainable, high quality and low-cost component of animal feed. Here, we discuss how insect farming can promote inclusive business for smallholder farmers in the agribusiness value chain. Inclusive business models involving insects as ingredients in feed may contribute to solving socio-economic and environmental problems in developing countries, aligning with the United Nations’ Sustainable Development Goals. With low initial capital investments, smallholder insect farmers have good opportunities to increase productivity, improve their livelihood and contribute to food security and a circular economy.

Effect of dietary replacement of fishmeal by insect meal on growth performance, blood profiles and economics of growing pigs in Kenya
Chia, Shaphan Y. ; Tanga, Chrysantus M. ; Osuga, Isaac M. ; Alaru, Alphonce O. ; Mwangi, David M. ; Githinji, Macdonald ; Subramanian, Sevgan ; Fiaboe, Komi K.M. ; Ekesi, Sunday ; Loon, Joop J.A. van; Dicke, Marcel - \ 2019
Animals 9 (2019)10. - ISSN 2076-2615
Alternative protein - Animal feeds - Blood parameters - Cost benefit analysis - Growing pigs - Insect larval meal - Return on investment

Pig production is one of the fastest growing livestock sectors. Development of this sector is hampered by rapidly increasing costs of fishmeal (FM), which is a common protein source in animal feeds. Here, we explored the potential of substituting FM with black soldier fly larval meal (BSFLM) on growth and blood parameters of pigs as well as economic aspects. At weaning, 40 hybrid pigs, i.e., crossbreeds of purebred Large White and Landrace were randomly assigned to five iso-nitrogenous and iso-energetic dietary treatments: Control (0% BSFLM and 100% FM (T0)), and FM replaced at 25% (T25), 50% (T50), 75% (T75) and 100% (T100) with BSFLM. Average daily feed intake (ADFI), average daily gain (ADG), body weight gain (BWG) and feed conversion ratio (FCR) were calculated for the whole trial. Hematological and serum biochemical parameters, the cost– benefit ratio (CBR) and return on investment (RoI) were evaluated. No significant effect of diet type was observed on feed intake and daily weight gain. Red or white blood cell indices did not differ among diets. Pigs fed T25, T75 and T100, had lower platelet counts compared to T0 and T50. Dietary inclusion of BSFLM did not affect blood total cholesterol, triglycerides, low-density lipoprotein and high-density lipoprotein. CBR and RoI were similar for the various diets. In conclusion, BSFLM is a suitable and cost-effective alternative to fishmeal in feed for growing pigs.

Leaf metabolic signatures induced by real and simulated herbivory in black mustard (Brassica nigra)
Papazian, Stefano ; Girdwood, Tristan ; Wessels, Bernard A. ; Poelman, Erik H. ; Dicke, Marcel ; Moritz, Thomas ; Albrectsen, Benedicte R. - \ 2019
Metabolomics 15 (2019)10. - ISSN 1573-3882 - p. 16 - 16.
Brassica nigra - Glucosinolates - Growth-defence allocation - Herbivore-induced responses - Leaf ontogeny - Metabolomics - Methyl jasmonate - Priming

INTRODUCTION: The oxylipin methyl jasmonate (MeJA) is a plant hormone active in response signalling and defence against herbivores. Although MeJA is applied experimentally to mimic herbivory and induce plant defences, its downstream effects on the plant metabolome are largely uncharacterized, especially in the context of primary growth and tissue-specificity of the response. OBJECTIVES: We investigated the effects of MeJA-simulated and real caterpillar herbivory on the foliar metabolome of the wild plant Brassica nigra and monitored the herbivore-induced responses in relation to leaf ontogeny. METHODS: As single or multiple herbivory treatments, MeJA- and mock-sprayed plants were consecutively exposed to caterpillars or left untreated. Gas chromatography (GC) and liquid chromatography (LC) time-of-flight mass-spectrometry (TOF-MS) were combined to analyse foliar compounds, including central primary and specialized defensive plant metabolites. RESULTS: Plant responses were stronger in young leaves, which simultaneously induced higher chlorophyll levels. Both MeJA and caterpillar herbivory induced similar, but not identical, accumulation of tricarboxylic acids (TCAs), glucosinolates (GSLs) and phenylpropanoids (PPs), but only caterpillar feeding led to depletion of amino acids. MeJA followed by caterpillars caused higher induction of defence compounds, including a three-fold increase in the major defence compound allyl-GSL (sinigrin). When feeding on MeJA-treated plants, caterpillars gained less weight indicative of the reduced host-plant quality and enhanced resistance. CONCLUSIONS: The metabolomics approach showed that plant responses induced by herbivory extend beyond the regulation of defence metabolism and are tightly modulated throughout leaf development. This leads to a new understanding of the plant metabolic potential that can be exploited for future plant protection strategies.

What makes a volatile organic compound a reliable indicator of insect herbivory?
Douma, Jacob C. ; Ganzeveld, Laurens N. ; Unsicker, Sybille B. ; Boeckler, Andreas ; Dicke, Marcel - \ 2019
Plant, Cell & Environment (2019). - ISSN 0140-7791
biogenic volatile organic compound (BVOC) - emission - herbivore induced plant volatile (HIPV) - hydroxyl radical - nitrate radical - oxidation - ozone - Populus nigra

Plants that are subject to insect herbivory emit a blend of so-called herbivore-induced plant volatiles (HIPVs), of which only a few serve as cues for the carnivorous enemies to locate their host. We lack understanding which HIPVs are reliable indicators of insect herbivory. Here, we take a modelling approach to elucidate which physicochemical and physiological properties contribute to the information value of a HIPV. A leaf-level HIPV synthesis and emission model is developed and parameterized to poplar. Next, HIPV concentrations within the canopy are inferred as a function of dispersion, transport and chemical degradation of the compounds. We show that the ability of HIPVs to reveal herbivory varies from almost perfect to no better than chance and interacts with canopy conditions. Model predictions matched well with leaf-emission measurements and field and laboratory assays. The chemical class a compound belongs to predicted the signalling ability of a compound only to a minor extent, whereas compound characteristics such as its reaction rate with atmospheric oxidants, biosynthesis rate upon herbivory and volatility were much more important predictors. This study shows the power of merging fields of plant–insect interactions and atmospheric chemistry research to increase our understanding of the ecological significance of HIPVs.

Nieuwe inzichten in effect van neonicotinoïden op nuttige insecten
Dicke, Marcel - \ 2019
Imidaclopridcoating blijkt toch onschadelijk
Dicke, Marcel ; Calvo Agudo, Miguel - \ 2019
Neonicotinoids in excretion product of phloem-feeding insects kill beneficial insects
Calvo-Agudo, Miguel ; González-Cabrera, Joel ; Picó, Yolanda ; Calatayud-Vernich, Pau ; Urbaneja, Alberto ; Dicke, Marcel ; Tena, Alejandro - \ 2019
Proceedings of the National Academy of Sciences of the United States of America 116 (2019)34. - ISSN 0027-8424 - p. 16817 - 16822.
Pest control in agriculture is mainly based on the application of insecticides, which may impact nontarget beneficial organisms leading to undesirable ecological effects. Neonicotinoids are among the most widely used insecticides. However, they have important negative side effects, especially for pollinators and other beneficial insects feeding on nectar. Here, we identify a more accessible exposure route: Neonicotinoids reach and kill beneficial insects that feed on the most abundant carbohydrate source for insects in agroecosystems, honeydew. Honeydew is the excretion product of phloem-feeding hemipteran insects such as aphids, mealybugs, whiteflies, and psyllids. We allowed parasitic wasps and pollinating hoverflies to feed on honeydew from hemipterans feeding on trees treated with thiamethoxam or imidacloprid, the most commonly used neonicotinoids. LC-MS/MS analyses demonstrated that both neonicotinoids were present in honeydew. Honeydew with thiamethoxam was highly toxic to both species of beneficial insects, and honeydew with imidacloprid was moderately toxic to hoverflies. Collectively, our data provide strong evidence for honeydew as a route of insecticide exposure that may cause acute or chronic deleterious effects on nontarget organisms. This route should be considered in future environmental risk assessments of neonicotinoid applications.

Neonics wel of niet schadelijker?
Dicke, Marcel - \ 2019
Cross-seasonal legacy effects of arthropod community on plant fitness in perennial plants
Stam, Jeltje M. ; Kos, Martine ; Dicke, Marcel ; Poelman, Erik H. - \ 2019
Journal of Ecology 107 (2019)5. - ISSN 0022-0477 - p. 2451 - 2463.
In perennial plants, interactions with other community members during the vegetative growth phase may influence community assembly during subsequent reproductive years and may influence plant fitness. It is well known that plant responses to herbivory affect community assembly within a growing season, but whether plant‐herbivore interactions result in legacy effects on community assembly across seasons has received little attention. Moreover, whether plant‐herbivore interactions during the vegetative growing season are important in predicting plant fitness directly or indirectly through legacy effects is poorly understood.

Here, we tested whether plant‐arthropod interactions in the vegetative growing season of perennial wild cabbage plants, Brassica oleracea, result in legacy effects in arthropod community assembly in the subsequent reproductive season and whether legacy effects have plant fitness consequences. We monitored the arthropod community on plants that had been induced with either aphids, caterpillars or no herbivores in a full‐factorial design across two years. We quantified the plant traits ‘height', ‘number of leaves' and ‘number of flowers' to understand mechanisms that may mediate legacy effects. We measured seed production in the second year to evaluate plant fitness consequences of legacy effects.

Although we did not find community responses to the herbivory treatments, our data show that community composition in one year leaves a legacy on community composition in a second year: predator community composition co‐varied across years. Structural Equation Modelling analyses indicated that herbivore communities in the vegetative year correlated with plant performance traits that may have caused a legacy effect on especially predator community assembly in the subsequent reproductive year. Interestingly, the legacy of the herbivore community in the vegetative year predicted plant fitness better than the herbivore community that directly interacted with plants in the reproductive year.

Synthesis Thus, legacy effects of plant‐herbivore interactions affect community assembly on perennial plants across growth seasons and these processes may affect plant reproductive success. We argue that plant‐herbivore interactions in the vegetative phase as well as cross seasonal legacy effects caused by plant responses to arthropod herbivory may be important in perennial plant trait evolution such as ontogenetic variation in growth and defence strategies.
Use of visual and olfactory cues of flowers of two brassicaceous species by insect pollinators
Barragán-Fonseca, Katherine Y. ; Loon, Joop J.A. van; Dicke, Marcel ; Lucas-Barbosa, Dani - \ 2019
Ecological Entomology (2019). - ISSN 0307-6946
Odour cues - plant volatiles - pollinators - post-pollination changes - visual cues

1. Pollinating insects exploit visual and olfactory cues associated with flower traits indicative of flower location and reward quality. Pollination can induce changes in these flower-associated cues, thereby influencing the behaviour of flower visitors. 2. This study investigated the main cues exploited by the syrphid fly Episyrphus balteatus and the butterfly Pieris brassicae when visiting flowers of Brassica nigra and Raphanus sativus plants. Whether pollen is used as a cue and whether pollination-induced changes affect flower volatile emission and the behavioural responses of the two pollinator species were also studied. 3. Pollinator preference was investigated by offering visual and olfactory cues individually as well as simultaneously in two-choice bioassays. Plant treatments included emasculation, hand-pollination and untreated control plants. The composition of flower volatiles from pollinated and unpollinated control plants was analysed by gas chromatography-mass spectrometry. 4. Both pollinators exhibited a strong bias for visual cues over olfactory cues. Neither pollinator used pollen as a cue. However, E. balteatus discriminated between newly opened and long-open flowers at short distance only when pollen was available. Flower visits by pollinators were influenced by pollination-induced changes in B. nigra but not R. sativus flowers. Pieris brassicae only responded to pollination-induced changes when visual and olfactory cues were offered simultaneously. The blend of volatiles emitted by B. nigra, but not R. sativus inflorescences was affected by pollination. 5. Collectively, the findings of this study show that different pollinators exploit different visual and olfactory traits when searching for flowers of two brassicaceous plant species.

Volatiles of pathogenic and non-pathogenic soil-borne fungi affect plant development and resistance to insects
Moisan, Kay ; Cordovez, Viviane ; Zande, Els M. van de; Raaijmakers, Jos M. ; Dicke, Marcel ; Lucas-Barbosa, Dani - \ 2019
Oecologia 190 (2019)3. - ISSN 0029-8549 - p. 589 - 604.
Arabidopsis thaliana - Fungal volatiles - Plant development - Plant pathogens - Plant resistance

Plants are ubiquitously exposed to a wide diversity of (micro)organisms, including mutualists and antagonists. Prior to direct contact, plants can perceive microbial organic and inorganic volatile compounds (hereafter: volatiles) from a distance that, in turn, may affect plant development and resistance. To date, however, the specificity of plant responses to volatiles emitted by pathogenic and non-pathogenic fungi and the ecological consequences of such responses remain largely elusive. We investigated whether Arabidopsis thaliana plants can differentiate between volatiles of pathogenic and non-pathogenic soil-borne fungi. We profiled volatile organic compounds (VOCs) and measured CO2 emission of 11 fungi. We assessed the main effects of fungal volatiles on plant development and insect resistance. Despite distinct differences in VOC profiles between the pathogenic and non-pathogenic fungi, plants did not discriminate, based on plant phenotypic responses, between pathogenic and non-pathogenic fungi. Overall, plant growth was promoted and flowering was accelerated upon exposure to fungal volatiles, irrespectively of fungal CO2 emission levels. In addition, plants became significantly more susceptible to a generalist insect leaf-chewing herbivore upon exposure to the volatiles of some of the fungi, demonstrating that a prior fungal volatile exposure can negatively affect plant resistance. These data indicate that plant development and resistance can be modulated in response to exposure to fungal volatiles.

Ecology of Plastic Flowers
Rusman, Quint ; Lucas-Barbosa, Dani ; Poelman, Erik H. ; Dicke, Marcel - \ 2019
Trends in Plant Science 24 (2019)6. - ISSN 1360-1385 - p. 725 - 740.
flower traits - flower visitors - herbivore-induced plant responses - phenotypic plasticity - plant defense - specificity

Plant phenotypic plasticity in response to herbivore attack includes changes in flower traits. Such herbivore-induced changes in flower traits have consequences for interactions with flower visitors. We synthesize here current knowledge on the specificity of herbivore-induced changes in flower traits, the underlying molecular mechanisms, and the ecological consequences for flower-associated communities. Herbivore-induced changes in flower traits seem to be largely herbivore species-specific. The extensive plasticity observed in flowers influences a highly connected web of interactions within the flower-associated community. We argue that the adaptive value of herbivore-induced plant responses and flower plasticity can be fully understood only from a community perspective rather than from pairwise interactions.

Data from: Cross-seasonal legacy effects of arthropod community on plant fitness in perennial plants
Stam, J.M. ; Kos, M. ; Dicke, M. ; Poelman, E.H. - \ 2019
Plant–herbivore interactions - community composition - community dynamics - log term effects - seed set - insect-plant interactions - priority effect - Brassica oleracea
1. In perennial plants, interactions with other community members during the vegetative growth phase may influence community assembly during subsequent reproductive years and may influence plant fitness. It is well known that plant responses to herbivory affect community assembly within a growing season, but whether plant-herbivore interactions result in legacy effects on community assembly across seasons has received little attention. Moreover, whether plant-herbivore interactions during the vegetative growing season are important in predicting plant fitness directly or indirectly through legacy effects is poorly understood. 2. Here, we tested whether plant-arthropod interactions in the vegetative growing season of perennial wild cabbage plants, Brassica oleracea, result in legacy effects in arthropod community assembly in the subsequent reproductive season and whether legacy effects have plant fitness consequences. We monitored the arthropod community on plants that had been induced with either aphids, caterpillars or no herbivores in a full-factorial design across two years. We quantified the plant traits ‘height’, ‘number of leaves’ and ‘number of flowers’ to understand mechanisms that may mediate legacy effects. We measured seed production in the second year to evaluate plant fitness consequences of legacy effects. 3. Although we did not find community responses to the herbivory treatments, our data show that community composition in one year leaves a legacy on community composition in a second year: predator community composition co-varied across years. Structural Equation Modelling analyses indicated that herbivore communities in the vegetative year correlated with plant performance traits that may have caused a legacy effect on especially predator community assembly in the subsequent reproductive year. Interestingly, the legacy of the herbivore community in the vegetative year predicted plant fitness better than the herbivore community that directly interacted with plants in the reproductive year. 4. Synthesis Thus, legacy effects of plant-herbivore interactions affect community assembly on perennial plants across growth seasons and these processes may affect plant reproductive success. We argue that plant-herbivore interactions in the vegetative phase as well as cross seasonal legacy effects caused by plant responses to arthropod herbivory may be important in perennial plant trait evolution such as ontogenetic variation in growth and defence strategies.
Defense of pyrethrum flowers: repelling herbivore and recruiting carnivore by producing aphid alarm pheromone
Ruijter, N.C.A. de; Dicke, M. ; Jongsma, M.A. - \ 2019
New Phytologist 223 (2019)3. - ISSN 0028-646X - p. 1607 - 1620.
E)‐β‐farnesene (EβF) is the predominant constituent of the alarm pheromone of most aphid pest species. Moreover, natural enemies of aphids use EβF to locate their aphid prey. Some plant species emit EβF, potentially as a defense against aphids, but field demonstrations are lacking.Here, we present field and laboratory studies of flower defense showing that ladybird beetles are predominantly attracted to young stage‐2 pyrethrum flowers that emitted the highest and purest levels of EβF. By contrast, aphids were repelled by EβF emitted by S2 pyrethrum flowers. Although peach aphids can adapt to pyrethrum plants in the laboratory, aphids were not recorded in the field. Pyrethrum's (E)‐β‐farnesene synthase (EbFS) gene is strongly expressed in inner cortex tissue surrounding the vascular system of the aphid‐preferred flower receptacle and peduncle, leading to elongated cells filled with EβF. Aphids that probe these tissues during settlement encounter and ingest plant EβF as evidenced by the release in honeydew. These EβF concentrations in honeydew induce aphid alarm responses, suggesting an extra layer of this defense.Collectively, our data elucidate a defensive mimicry in pyrethrum flowers: the developmentally regulated and tissue‐specific EβF accumulation and emission both prevents attack by aphids and recruits aphid predators as bodyguards.
Airborne host–plant manipulation by whiteflies via an inducible blend of plant volatiles
Zhang, Peng Jun ; Wei, Jia Ning ; Zhao, Chan ; Zhang, Ya Fen ; Li, Chuan You ; Liu, Shu Sheng ; Dicke, Marcel ; Yu, Xiao Ping ; Turlings, Ted C.J. - \ 2019
Proceedings of the National Academy of Sciences of the United States of America 116 (2019)15. - ISSN 0027-8424 - p. 7387 - 7396.
Herbivore-induced plant volatiles - Jasmonic acid - Salicylic acid - Tomato - Whiteflies

The whitefly Bemisia tabaci is one of the world’s most important invasive crop pests, possibly because it manipulates plant defense signaling. Upon infestation by whiteflies, plants mobilize salicylic acid (SA)-dependent defenses, which mainly target pathogens. In contrast, jasmonic acid (JA)-dependent defenses are gradually suppressed in whitefly-infested plants. The down-regulation of JA defenses make plants more susceptible to insects, including whiteflies. Here, we report that this host–plant manipulation extends to neighboring plants via airborne signals. Plants respond to insect attack with the release of a blend of inducible volatiles. Perception of these volatiles by neighboring plants usually primes them to prepare for an imminent attack. Here, however, we show that whitefly-induced tomato plant volatiles prime SA-dependent defenses and suppress JA-dependent defenses, thus rendering neighboring tomato plants more susceptible to whiteflies. Experiments with volatiles from caterpillar-damaged and pathogen-infected plants, as well as with synthetic volatiles, confirm that whiteflies modify the quality of neighboring plants for their offspring via whitefly-inducible plant volatiles.

Een onderzoek naar mogelijke relaties tussen de afname van weidevogels en de aanwezigheid van bestrijdingsmiddelen op veehouderijbedrijven : onderzoeksrapport
Buijs, Jelmer ; Samwel-Mantingh, Margriet ; Berendse, F. ; Mansvelt, J.D. van; Berg, M. van der; Ragas, A.M.J. ; Oomen, Gerard ; Dicke, M. - \ 2019
Bennekom : - 169 p.
animal welfare - wild animals - animal health - grassland birds
Effects of dietary protein and carbohydrate on life-history traits and body protein and fat contents of the black soldier fly Hermetia illucens
Barragan-Fonseca, Karol B. ; Gort, Gerrit ; Dicke, Marcel ; Loon, Joop J.A. van - \ 2019
Physiological Entomology 44 (2019)2. - ISSN 0307-6962 - p. 148 - 159.
Body nutrient composition - fecundity - food quality - larval performance - macronutrients - nutrition

We investigate how the black soldier fly Hermetia illucens L. (Diptera: Stratiomyidae) responds to dietary protein (P) and carbohydrate (C) contents and the P:C ratio in terms of both immature and adult life-history traits, as well as effects on larval body composition. Nine chicken-feed based diets varying in their P:C ratio are formulated. We test three protein concentrations (10%, 17% and 24%) and three carbohydrate concentrations (35%, 45% and 55%) and their combinations. All nine diets support the complete development and reproduction of this species. Survival is high on all diets. Development time, larval yield, larval crude fat and egg yield are more influenced by P and C contents than by the P:C ratio. Low contents result in a shorter development time. Larval yield is higher on diets with higher C-contents. Pupal development is faster on a low dietary P-content for all three C-contents. Egg yield only increases when P-content increases, although it also varies with the P:C ratio. Larval crude protein content is similar on all nine diets but increases when C-content is low (10%) in P10 and P17. Larval crude fat content is high at P24-diets irrespective of C-content. We conclude that a high macronutrient content combined with a low P:C ratio positively affects H. illucens performance. The diet P17:C55 supports the highest larval and adult performance and results in a high larval body protein content and an intermediate crude fat content.

Raising the steaks: How one city in the Netherlands wants to feed the world
Barbosa, Maria ; Meer, Ingrid van der; Dicke, Marcel ; Werf, Adrie van der; Goot, Atze Jan van der; Wichers, Harry - \ 2019
The plastidial metabolite 2-C-methyl-D-erythritol-2,4-cyclodiphosphate modulates defence responses against aphids
Onkokesung, Nawaporn ; Reichelt, Michael ; Wright, Louwrance P. ; Phillips, Michael A. ; Gershenzon, Jonathan ; Dicke, Marcel - \ 2019
Plant, Cell & Environment 42 (2019)7. - ISSN 0140-7791 - p. 2309 - 2323.
aphid resistance - Arabidopsis - indole glucosinolates - phloem-sucking herbivores - phytohormone signalling - retrograde signalling - secondary metabolites

Feeding by insect herbivores such as caterpillars and aphids induces plant resistance mechanisms that are mediated by the phytohormones jasmonic acid (JA) and salicylic acid (SA). These phytohormonal pathways often crosstalk. Besides phytohormones, methyl-D-erythriol-2,4-cyclodiphosphate (MEcPP), the penultimate metabolite in the methyl-D-erythritol-4-phosphate pathway, has been speculated to regulate transcription of nuclear genes in response to biotic stressors such as aphids. Here, we show that MEcPP uniquely enhances the SA pathway without attenuating the JA pathway. Arabidopsis mutant plants that accumulate high levels of MEcPP (hds3) are highly resistant to the cabbage aphid (Brevicoryne brassicae), whereas resistance to the large cabbage white caterpillar (Pieris brassicae) remains unaltered. Thus, MEcPP is a distinct signalling molecule that acts beyond phytohormonal crosstalk to induce resistance against the cabbage aphid in Arabidopsis. We dissect the molecular mechanisms of MEcPP mediating plant resistance against the aphid B. brassicae. This shows that MEcPP induces the expression of genes encoding enzymes involved in the biosynthesis of several primary and secondary metabolic pathways contributing to enhanced resistance against this aphid species. A unique ability to regulate multifaceted molecular mechanisms makes MEcPP an attractive target for metabolic engineering in Brassica crop plants to increase resistance to cabbage aphids.

Involvement of sweet pepper CaLOX2 in jasmonate-dependent induced defence against Western flower thrips
Sarde, Sandeep J. ; Bouwmeester, Klaas ; Venegas-Molina, Jhon ; David, Anja ; Boland, Wilhelm ; Dicke, Marcel - \ 2019
Journal of Integrative Plant Biology 61 (2019)10. - ISSN 1672-9072 - p. 1085 - 1098.

Insect herbivory can seriously hinder plant performance and reduce crop yield. Thrips are minute cell-content-feeding insects that are important vectors of viral plant pathogens, and are serious crop pests. We investigated the role of a sweet pepper (Capsicum annuum) lipoxygenase gene, CaLOX2, in the defense of pepper plants against Western flower thrips (Frankliniella occidentalis). This was done through a combination of in-silico, transcriptional, behavioral and chemical analyses. Our data show that CaLOX2 is involved in jasmonic acid (JA) biosynthesis and mediates plant resistance. Expression of the JA-related marker genes, CaLOX2 and CaPIN II, was induced by thrips feeding. Silencing of CaLOX2 in pepper plants through virus-induced gene silencing (VIGS) resulted in low levels of CaLOX2 transcripts, as well as significant reduction in the accumulation of JA, and its derivatives, upon thrips feeding compared to control plants. CaLOX2-silenced pepper plants exhibited enhanced susceptibility to thrips. This indicates that CaLOX2 mediates JA-dependent signaling, resulting in defense against thrips. Furthermore, exogenous application of JA to pepper plants increased plant resistance to thrips, constrained thrips population development and made plants less attractive to thrips. Thus, a multidisciplinary approach shows that an intact lipoxygenase pathway mediates various components of sweet pepper defense against F. occidentalis.

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.