From species to trait evolution in Aethionema (Brassicaceae)
Mohammadin, Setareh - \ 2017
Wageningen University. Promotor(en): M.E. Schranz. - Wageningen : Wageningen University - ISBN 9789463431385 - 125
brassicaceae - evolution - rna - genomes - genetic diversity - phytogeography - glucosinolates - quantitative trait loci - next generation sequencing - brassicaceae - evolutie - rna - genomen - genetische diversiteit - plantengeografie - glucosinolaten - loci voor kwantitatief kenmerk - next generation sequencing
The plant family Brassicaceae (or crucifers) is an economically important group that includes many food crops (e.g. cabbages and radishes), horticultural species (e.g. Draba, Iberis, Lunaria), and model plant species (particularly Arabidopsis thaliana). Because of the fundamental importance of A. thaliana to plant biology, it makes the Brassicaceae an ideal system for comparative genomics and to test wider evolutionary, ecological and speciation hypotheses. One such hypothesis is the ‘Whole Genome Duplication Radiation Lag Time’ (WGD-RLT) model for the role of polyploidy on the evolution of important plant families such as the Brassicaceae. The WGD-RLT model indicates a higher rate of diversification of a core-group compared to its sister group, due to a lag time after a whole genome duplication event that made it possible for novel traits or geo- or ecological events to increase the core groups diversification rate.
Aethionema is the species-poor sister genus of the core Brassicaceae and hence is at an important comparative position to analyse trait and genomic evolution of the species-rich core group. Aethionema species occur mainly in the western Irano-Turanian region, which is concordantly the biodiversity hotspot of the Brassicaceae family. Moreover comparing Aethionema to the Brassicaceae core group can help us to understand and test the ‘WGD-RLT’ model. However to be able to do so we first need to know more about Aethionema. In this thesis, I investigated various levels of evolutionary change (from macro, to micro to trait evolution) within the genus Aethionema, with a major focus the emerging model species Aethionema arabicum.
Next generation sequencing has made it possible to use the genomes of many species in a comparative framework. However, the formation of proteins and enzymes, and in the end the phenotype of the whole plant, relies on transcription from particular regions of the genome including genes. Hence, the transcriptome makes it possible to assess the functional parts of the genome. However, the functional part of the genome not only relies on the protein coding genes. Gene regulatory elements like promoters and long non-coding RNAs function as regulators of gene expression and hence are involved in increasing or decreasing transcription. In Chapter 2 I used the transcriptome of four different Aethionema species to understand the lineage specificity of these long non-coding RNAs. Moreover in a comparison with the Brassicaceae core group and Brassicaceae’s sister family the Cleomaceae I show that although the position of long non-coding RNAs can be conserved, their sequences do not have to be.
Most of the Aethionema species occur in the Irano-Turanian region, a politically instable region, making it hard for scientist to collect from. However the natural history collections made throughout the last centuries are a great resource. Combing these collections with the newest sequencing techniques, e.g. next generation sequencing, have allowed me to infer the phylogeny of ~75% of the known Aethionema species in a time calibrated and historical biogeographical framework. Hence, I was able to establish that Aethionema species likely originated from the Anatolian Diagonal and that major geological events like the uplift of the Turkish and Iranian plateau have had a hand in their speciation (Chapter 3).
To examine species-level processes I sequenced and analysed transcriptomes of eight Ae. arabicum accessions coming from Cyprus, Iran and Turkey to investigate population structure, genetic diversity and local adaptation (Chapter 4). The most prominent finding was a ploidy difference between the Iranian and Turkish/Cypriotic lines, whereby the former were (allo)tetraploid and the latter diploid. The tetraploid Iranian lines seem to have one set of alleles from the Turkish/Cypriotic gene-pool. However we do not know where the other alleles come from. In addition to the differences in ploidy level there are also differences in glucosinolate defence compounds between these two populations (Iranian vs Turkish/Cypriotic), with the Iranian lines lacking the diversity and concentration of indolic glucosinolates that the Turkish/Cypriotic lines have. This chapter serves as a good resource and starting point for future research in the region, maybe by using the natural history collections that are at hand.
Glucosinolates (i.e. mustard oils) are mainly made by Brassicales species, with their highest structural diversity in the Brassicaceae. In Chapter 5, I examined two Ae. arabicum lines (CYP and TUR) and their recombinant inbred lines to assess glucosinolate composition in different tissues and throughout the plants development. The levels of glucosinolates in the leaves changed when Ae. arabicum went from vegetative to a reproductive state. Moreover, a major difference in glucosinolate content (up to 10-fold) between CYP and TUR indicates a likely regulatory pathway outside of the main glucosinolate biosynthesis pathway. Multi-trait and multi-environment QTL analyses based on leaves, reproductive tissues and seeds identified a single major QTL. Fine mapping this region reduced the interval to only fifteen protein coding genes, including the two most intriguing candidates: FLOWERING LOCUS C (FLC) and the sulphate transporter SULTR2;1. These findings show an interesting correlation between development and defence.
Finally, Chapter 6 gives a final discussion of this thesis and its results. It brings the different topics together, put them in a bigger picture and look forward to new research possibilities.
An evolutionary and functional genomics study of Noccaea caerulescens, a heavy metal hyperaccumulating plant species
Wang, Y. - \ 2016
Wageningen University. Promotor(en): Maarten Koornneef, co-promotor(en): Mark Aarts. - Wageningen : Wageningen University - ISBN 9789462578562 - 190
brassicaceae - genomics - hyperaccumulator plants - heavy metals - genes - genetic variation - brassicaceae - genomica - hyperaccumulerende planten - zware metalen - genen - genetische variatie
Noccaea caerulescens is the only known Zn/Cd/Ni hyperaccumulator. The Ganges accession (2n = 14) has an, yet unpublished, genome size of ~319 Mb, with 29,712 predicted genes representing 15,874 gene families. This species is distributed mainly in Europe. Three ecotypes can be distinguished: two metallicolous ecotypes, resident to serpentine soil (Ni enriched) and calamine soil (Zn/Cd enriched), and a non-metallicolous ecotype, growing on regular, non-metalliferous soils. The physiological differences that underlie variation in heavy metal accumulation and tolerance are well-understood, and the molecular basis of hyperaccumulation and tolerance has been explored by transcript profiling in the presence of metals and by comparative transcriptome analysis using N. caerulescens and non-hyperaccumulators such as Arabidopsis thaliana. The genetic variation which emerged during the evolution of metal hyperaccumulation has not yet been investigated. The work described in this thesis considers the identification of genetic variation under selection for Zn/Cd hyperaccumulation and tolerance by next generation resequencing of the wild metallicolous (calamine) and non-metallicolous populations and the generation of a mutant N. caerulescens library for functional analysis. The regulation of flowering time was also investigated, using early flowering mutants selected from the mutant library.
The importance of phenology in studies of plant-herbivore-parasitoid interactions
Fei, Minghui - \ 2016
Wageningen University. Promotor(en): Louise Vet; J.A. Harvey; Rieta Gols. - Wageningen : Wageningen University - ISBN 9789462576551 - 170
016-3952 - phenology - plant-herbivore interactions - parasitoids - interactions - annuals - insects - pieris brassicae - cotesia glomerata - brassicaceae - host plants - fenologie - plant-herbivoor relaties - parasitoïden - interacties - eenjarigen - insecten - pieris brassicae - cotesia glomerata - brassicaceae - waardplanten
Thesis title: The importance of phenology in studies of plant-herbivore-parasitoid interactions
Author: Minghui Fei
As food resources of herbivorous insects, the quality and quantity of plants can directly affect the performance of herbivorous insects and indirectly affect the performance of natural enemies of the herbivorous insects. In nature, plant quality and quantity are dynamic and can change in individual plants over the course of a single growing season. Many multivoltine insects are known to attack short-lived annual plants that are present for only 2 or 3 months in the field. These short-lived plants may germinate and grow at different times and locations during the growing season. In this situation, each generation of insects is obligated to search for potentially new species of food plants across the growing season, which may differ in qualitative and quantitative traits. The aim of this thesis was to explore how seasonal phenology of potential food plants effects a multivoltine herbivore-parasitoid interaction. In particular, I examined potential qualitative and quantitative constraints imposed by the seasonal phenology of several food-plant species on the development and survival as well as on oviposition decisions of a gregarious specialist herbivorous insect and its natural enemy that both have multiple generations per year. As a model system, I used a multivoltine specialist herbivorous insect associated with different plant species, the large cabbage white butterfly, Pieris brassicae L., and its specialized multivoltine endoparasitoid, Cotesia glomerata L.. Pieris brassicae primary feed on plants in the large family Brassicaceae. I used three annual brassicaceous plants, Brassica rapa L., Sinapis arvensis L., and Brassica nigra L., which grow rapidly and exhibit differing phenologies, each growing within a short period of time and with little temporal overlap amongst them. These plants are known to serve as food plants for successive generations of P. brassicae and related species.
In bioassay experiments under controlled greenhouse and semi-field conditions, I found that P. brassicae and C. glomerata were marginally affected by seasonal-related and plant species-specific differences in food-plant quality. Pieris brassicae was also marginally affected by the ontogenetic variations in food-plant quality. In addition, food-plant shifts in different generations had small effects (both positive and negative depending on plant species) on the performance of P. brassica and C. glomerata. Survival and performance of P. brassicae was much more constrained by quantitative than qualitative aspects of the food plant. The survival and performance of C. glomerata was also affected by similar quantitative constraints as that of its host.
In behavioural experiments under controlled greenhouse and semi-field conditions, I found that female P. brassicae oviposition preference order for food plants declined with plant age of different plant species (S. arvensis and B. nigra). Female P. brassicae butterflies may ‘anticipate’ future quantity or quality potential of the food plants when choosing oviposition sites. Pre-adult experience had minor effects on P. brassicae butterfly oviposition preference and had no effect on C. glomerata landing preference. Pieris brassicae also did not exhibit consistent preference for any of the plant species, whereas C. glomerata had a clear preference on B. rapa. Further studies on trophic interactions need to incorporate more spatial and temporal realism, i.e. plant species shifts (temporally dynamic interactions) as well as to ‘track’ insect foraging behaviour in the field (spatially dynamic interactions). Thus far virtually nothing is known about these areas or as to the success of naïve insects in locating new patches of food plants or hosts in different habitats.
Karyotype evolution in apomictic Boechera and the origin of the aberrant chromosomes
Mandáková, T. ; Schranz, M.E. ; Sharbel, T.F. ; Jong, J.H.S.G.M. de; Lysak, M. - \ 2015
The Plant Journal 82 (2015)5. - ISSN 0960-7412 - p. 785 - 793.
holboellii complex - genus boechera - genome sequence - centric fission - brassicaceae - arabidopsis - centromere - phylogeny - arabis - reproduction
Chromosome rearrangements may result in both decrease and increase of chromosome numbers. Here we have used comparative chromosome painting (CCP) to reconstruct the pathways of descending and ascending dysploidy in the genus Boechera (tribe Boechereae, Brassicaceae). We describe the origin and structure of three Boechera genomes and establish the origin of the previously described aberrant Het and Del chromosomes found in Boechera apomicts with euploid (2n = 14) and aneuploid (2n = 15) chromosome number. CCP analysis allowed us to reconstruct the origin of seven chromosomes in sexual B. stricta and apomictic B. divaricarpa from the ancestral karyotype (n = 8) of Brassicaceae lineage I. Whereas three chromosomes (BS4, BS6, and BS7) retained their ancestral structure, five chromosomes were reshuffled by reciprocal translocations to form chromosomes BS1-BS3 and BS5. The reduction of the chromosome number (from x = 8 to x = 7) was accomplished through the inactivation of a paleocentromere on chromosome BS5. In apomictic 2n = 14 plants, CCP identifies the largely heterochromatic chromosome (Het) being one of the BS1 homologues with the expansion of pericentromeric heterochromatin. In apomictic B. polyantha (2n = 15), the Het has undergone a centric fission resulting in two smaller chromosomes – the submetacentric Het' and telocentric Del. Here we show that new chromosomes can be formed by a centric fission and can be fixed in populations due to the apomictic mode of reproduction.
Models of the fate of glucosinolates in Brassicaceae from processing to digestion
Kruse, I. - \ 2015
Wageningen University. Promotor(en): Tiny van Boekel, co-promotor(en): Matthijs Dekker; Ruud Verkerk. - Wageningen : Wageningen University - ISBN 9789462573178 - 140
glucosinolaten - brassicaceae - koolsoorten - broccoli - spruitjes - warmtebehandeling - thermische afbraak - masticatie - spijsvertering - stomen - kookmethoden - glucosinolates - brassicaceae - cabbages - broccoli - brussels sprouts - heat treatment - thermal degradation - mastication - digestion - steaming - cooking methods
Glucosinolates are secondary metabolites of Brassica vegetables. Glucosinolates are not bioactive themselves, but their hydrolysis products isothiocyanates have been associated with health benefits. The concentrations of glucosinolates and their break down products are strongly affected by processing of the vegetables, but are also affected by digestion conditions.
During thermal treatment of Brassicaceae, such as domestic cooking, different mechanisms affecting the content of glucosinolates can take place and were modelled in the present study: Lysis of plant cells and compartments, leaching of glucosinolates into the cooking water and thermal degradation of glucosinolates in both the intact vegetable tissue and in the cooking water. These mechanisms were described mathematically and the model parameters for broccoli, Brussels sprouts, red cabbage and white cabbage were estimated based on experimental results. Differences between the thermostability of the same glucosinolates originating from different Brassicaceae could be detected, as well as differences between the thermostability of the same glucosinolates in the vegetable matrix compared to that in cooking water. This mathematical model and the estimated parameters can be used to simulate the different glucosinolate contents in prepared foods considering the processing method. This should be a useful tool in food research and industry to make predictions about the nutritional quality of foods and to optimize their health related quality attributes.
In broccoli, the glucosinolate glucoraphanin and its breakdown products were further studied in an in vitro digestion study and an in vivo chewing study with five subjects. Upon cell damage, e.g. during chewing, the glucosinolate glucoraphanin is hydrolyzed by the endogenous enzyme myrosinase and, depending on the environmental conditions, sulforaphane or sulforaphane nitrile are produced.
The effect of steaming time (raw or steamed for 1, 2 or 3 min) and meal composition (with and without addition of protein (bovine serum albumin or lipid (olive oil)) on the conversion of glucoraphanin were studied in an in vitro digestion model and the bioaccessibility of released breakdown products investigated. The main formation of sulforaphane and sulforaphane nitrile from glucoraphanin occurred during the in vitro oral phase. The content of glucoraphanin, sulforaphane and sulforaphane nitrile did not degrade after digestion. Sulforaphane concentrations were up to 10-times higher in raw and 1-min steamed broccoli samples after the digestion compared to broccoli that was steamed 2 or 3 min. The addition of bovine serum albumin and olive oil had no influence on the formation and bioaccessibility of sulforaphane or sulforaphane nitrile. Meal preparation seems to have a much more pronounced effect on SF formation and bioaccessibility compared to meal composition.
In an in vitro study the effect of chewing time (11 s, 22 s, 30 s and 40 s) on differently steamed broccoli ( raw or steamed for 0.5-min, 1-min 2-min and 3-min) was studied. Chewing time influenced the amount of hydrolysis of glucoraphanin in raw and short steamed broccoli that contains active myrosinase (raw, 0.5-min and 1-min steamed), but not in broccoli that had been steamed longer. Steaming time showed to influence the oral hydrolysis of glucoraphanin. Both chewing time and steaming time influence the enzymatic breakdown of glucoraphanin in the mouth. Longer chewing times of raw and short steamed broccoli (0.5-min and 1-min), which contains active myrosinase, lead to more hydrolysis.
Isolation and identification of 4-a-rhamnosyloxy benzyl glucosinolate in Noccaea caerulescens showing intraspecific variation
Graaf, R.M. de; Krosse, S. ; Swolfs, A.E.M. ; Brinke, E. te; Prill, N. ; Leimu, R. ; Galen, P.M. van; Wang, Y. ; Aarts, M.G.M. ; Dam, N.M. van - \ 2015
Phytochemistry 110 (2015). - ISSN 0031-9422 - p. 166 - 171.
hyperaccumulator thlaspi-praecox - moringa-oleifera l. - mustard oil bomb - arabidopsis-thaliana - plants - isothiocyanates - stenopetala - accumulation - brassicaceae - profiles
Glucosinolates are secondary plant compounds typically found in members of the Brassicaceae and a few other plant families. Usually each plant species contains a specific subset of the ~130 different glucosinolates identified to date. However, intraspecific variation in glucosinolate profiles is commonly found. Sinalbin (4-hydroxybenzyl glucosinolate) so far has been identified as the main glucosinolate of the heavy metal accumulating plant species Noccaea caerulescens (Brassicaceae). However, a screening of 13 N. caerulescens populations revealed that in 10 populations a structurally related glucosinolate was found as the major component. Based on nuclear magnetic resonance (NMR) and mass spectrometry analyses of the intact glucosinolate as well as of the products formed after enzymatic conversion by sulfatase or myrosinase, this compound was identified as 4-a-rhamnosyloxy benzyl glucosinolate (glucomoringin). So far, glucomoringin had only been reported as the main glucosinolate of Moringa spp. (Moringaceae) which are tropical tree species. There was no apparent relation between the level of soil pollution at the location of origin, and the presence of glucomoringin. The isothiocyanate that is formed after conversion of glucomoringin is a potent antimicrobial and antitumor agent. It has yet to be established whether glucomoringin or its breakdown product have an added benefit to the plant in its natural habitat
Molecular and genetic basis of freezing tolerance in crucifer species
Heo, J. - \ 2014
Wageningen University. Promotor(en): Eric Schranz, co-promotor(en): P.H. van Tienderen; C.S. Testerink. - Wageningen : Wageningen University - ISBN 9789461738691 - 129
brassicaceae - invriezen - koudetolerantie - moleculaire biologie - plantengenetica - loci voor kwantitatief kenmerk - genen - kouderesistentie - brassicaceae - freezing - cold tolerance - molecular biology - plant genetics - quantitative trait loci - genes - cold resistance
Understanding genetic variation for freezing tolerance is important for unraveling an adaptative strategy of species and for finding out an effective way to improve crop productivity to unfavorable winter environments. The aim of this thesis was to examine natural variation for components of freezing tolerance beyond what has been done using the model organism Arabidopsis thaliana. Experiments using B. stricta were carried out to identify potentially novel and beneficial traits, and loci related to cold acclimation, or using a number of related Brassicaceae species were performed to understand mechanism for cold deacclimation. Our results strongly indicate differential regulatory mechanisms are involved in cold acclimation as well as cold deacclimation.Although we are still far from understanding those mechanisms, we have shown that exploiting natural variation using wild species provides new perspectives on ecologically important adaptation to cold, and may contribute to improve tolerance in crucifer species.
Preservation of seed viability during 25 years of storage under standard genebank conditions
Treuren, R. van; Groot, E.C. de; Hintum, T.J.L. van - \ 2013
Genetic Resources and Crop Evolution 60 (2013)4. - ISSN 0925-9864 - p. 1407 - 1421.
desiccation-tolerance - longevity - brassicaceae - germination - maturity
Maintaining sufficient viability is critical to the sustainability of ex situ conserved seed collections. For this reason, accessions are regenerated when viability falls below a predefined threshold. Viability is monitored by determining the germination ability of accessions at predefined time intervals. Optimizing the frequency of these germination tests, in order to avoid waste of resources, is hampered by the scarce availability of data about seed longevity, particularly for material maintained under genebank conditions. Here we report on the analysis of nearly 40,000 germination test results collected for a wide range of crop species over a 25-years period by the centre for genetic resources, the Netherlands (CGN), where seeds of genebank accessions are dried to 3–7 % moisture content and stored for the long term under near-vacuum in aluminium foil bags at -20 °C. The results indicate that seed viability is well maintained for the large majority of seed lots during the first 25 years after regeneration as only 3.3 % of the monitoring tests revealed below-threshold germination values. It is argued that the majority of these sub-standard seed lots are due to other causes than seed ageing, including dormancy problems and estimation error in germination testing. For material, maintained under the seed management procedures and storage conditions practiced by CGN, it is therefore recommended to delay the first germination monitoring tests to 25 years after regeneration.
Temporal dynamics of induced responses in Brassica juncea
Mathur, V. - \ 2012
Wageningen University. Promotor(en): Louise Vet; N.M. van Dam, co-promotor(en): A.S. Reddy. - S.l. : s.n. - ISBN 9789461733085 - 219
brassica juncea - insectenplagen - insect-plant relaties - gastheer parasiet relaties - herbivoren - brassicaceae - entomologie - ecologie - herbivoor-geinduceerde plantengeuren - brassica juncea - insect pests - insect plant relations - host parasite relationships - herbivores - brassicaceae - entomology - ecology - herbivore induced plant volatiles
Plants induce a suite of direct and indirect responses after herbivore attack. For utilizing these plant attributes in agriculture, it is important to compare the relative importance of these two defence types in the same plant species. Precise timing of these responses is vital for their effect on the herbivores feeding on the plant.
Multitrophic effects of plant resistance: from basic ecology to application in transgenic crops
Kos, M. - \ 2012
Wageningen University. Promotor(en): Marcel Dicke; Louise Vet, co-promotor(en): Joop van Loon. - S.l. : s.n. - ISBN 9789461732064 - 303
brassicaceae - verdedigingsmechanismen - insectenplagen - multitrofe interacties - parasitoïden - predatoren - glucosinolaten - vluchtige verbindingen - transgene planten - niet-doelorganismen - ecologische risicoschatting - brassicaceae - defence mechanisms - insect pests - multitrophic interactions - parasitoids - predators - glucosinolates - volatile compounds - transgenic plants - nontarget organisms - ecological risk assessment
Plants have evolved a wide array of direct and indirect resistance traits that prevent or reduce herbivory by insects. The aim of this thesis was to study the effects of direct and indirect plant resistance traits on the multitrophic interactions between brassicaceous plants, leaf-chewing and phloem-sucking aboveground herbivores and their natural enemies, parasitoids and predators. Brassica oleracea cultivars and Arabidopsis thaliana ecotypes were used that differ in production of glucosinolates or emission of volatiles, secondary plant chemicals acting in direct and indirect resistance respectively. There was a considerable intraspecific variation in the multitrophic effects of plant resistance traits in both plant species. In the field, bottom-up forces (plant chemistry and morphology) appeared more important for herbivore abundance than plant-mediated top-down forces (attraction and arrestment of natural enemies). Under greenhouse conditions, glucosinolates affected the performance of herbivores and that of their natural enemies. The performance of both a generalist and a specialist caterpillar was negatively correlated with glucosinolates in the plant, whereas that of a parasitoid of the specialist caterpillar was positively correlated with glucosinolates. Performance of a specialist aphid was positively correlated with phloem glucosinolates, and the aphid selectively sequestered these glucosinolates. Glucosinolates and their volatile hydrolytic products correlated negatively with the performance and behaviour of one of the predators of this aphid, but positively with that of one of its parasitoids. These results suggest that direct and indirect resistance traits can be in conflict, but they can also work in concert to enhance resistance to herbivores, depending on the biology of the herbivore and carnivore involved. Transgenic A. thaliana plants engineered to emit larger amounts of volatile terpenoids repelled the aphid, attracted the parasitoid, but did not affect predator behaviour.
These fundamental ecological results provided the background information required to strengthen ecological risk analysis for transgenicplants in the framework of the programme ‘Ecology Regarding Genetically modified Organisms’ funded by the Dutch government. The effects of transgenic plants on non-target organisms were compared with the baseline variation in the effects on non-target organisms that exists among conventional varieties or, in the case of A. thaliana, wild ecotypes. Four B. oleracea cultivars and three A. thaliana ecotypes were selected to represent the baseline variation. The baseline variation in effects on target and non-target organisms was relatively consistent over different environments, soil types and time. The effects of transgenic A. thaliana plants altered in direct and indirect resistance on non-target organisms were mostly within the baseline variation in these effects. Finally, the knowledge gained was applied to develop guidelines for governmental regulators that can be used to assess the potential ecological effects of transgenic crops on non-target organisms, in relation to baseline variation.
DOG1 expression is predicted by the seed-maturation envornment and contributes to geographical variation in germination in Arabidopsis thaliana
Chiang, G.C.K. ; Bartsch, M. ; Barua, D. ; Nakabayashi, K. ; Debieu, M. ; Kronholm, I. ; Koornneef, M. ; Soppe, W.J.J. ; Donohue, K. ; Meaux, J. De - \ 2011
Molecular Ecology 20 (2011)16. - ISSN 0962-1083 - p. 3336 - 3349.
flowering time gene - natural-selection - dormancy - brassicaceae - evolution - field - diversification - adaptation - characters - plasticity
Seasonal germination timing of Arabidopsis thaliana strongly influences overall life history expression and is the target of intense natural selection. This seasonal germination timing depends strongly on the interaction between genetics and seasonal environments both before and after seed dispersal. DELAY OF GERMINATION 1 (DOG1) is the first gene that has been identified to be associated with natural variation in primary dormancy in A. thaliana. Here, we report interaccession variation in DOG1 expression and document that DOG1 expression is associated with seed-maturation temperature effects on germination; DOG1 expression increased when seeds were matured at low temperature, and this increased expression was associated with increased dormancy of those seeds. Variation in DOG1 expression suggests a geographical structure such that southern accessions, which are more dormant, tend to initiate DOG1 expression earlier during seed maturation and achieved higher expression levels at the end of silique development than did northern accessions. Although elimination of the synthesis of phytohormone abscisic acid (ABA) results in the elimination of maternal temperature effects on dormancy, DOG1 expression predicted dormancy better than expression of genes involved in ABA metabolism
|Teelthandleiding groenbemesters : kruisbloemigen
Timmer, R.D. ; Korthals, G.W. ; Molendijk, L.P.G. - \ 2011
Kennisakker.nl 2004 (2011)1 mei.
groenbemesters - brassicaceae - akkerbouw - teelthandleidingen - green manures - arable farming - cultivation manuals
De kruisbloemigen danken hun goede naam als groenbemester vooral aan de snelle kieming, de vlotte grondbedekking en het feit dat ze ook bij lage temperaturen nog behoorlijk goed doorgroeien
Teelt en saldo van deder : Camelina sativa (deder) als alternatieve teelt
Voort, M.P.J. van der; Hartog, L. - \ 2010
Lelystad : PPO AGV (PPO-rapport ) - 34
camelina sativa - brassicaceae - olieleverende planten - zaadoliën - energiebalans - gebruikswaarde - duurzame energie - brandstofgewassen - biobased economy - teelthandleidingen - akkerbouw - camelina sativa - brassicaceae - oil plants - seed oils - energy balance - use value - sustainable energy - fuel crops - biobased economy - cultivation manuals - arable farming
Deder is een ‘nieuw’ gewas voor de Nederlandse landbouw. Deder (Camelina Sativa (L.)) is een gewas dat vroeger al in Europa werd gebruikt. Momenteel wordt deder niet meer verbouwd. De hernieuwde interesse komt vooral voort uit de zoektocht naar perspectiefvolle oliehoudende energiegewassen. In verband met de sterke interesse als energiegewas is de energie- en broeikasgasbalans van deder bepaald. Hieruit blijkt dat deder, afhankelijk van zomer- of wintervariant, licht lager of licht beter scoort als winterkoolzaad.
Plant-mediated multitrophic interactions between aboveground and belowground insects
Soler Gamborena, R. - \ 2009
Entomologische Berichten 69 (2009)6. - ISSN 0013-8827 - p. 202 - 210.
planten - insecten - bodeminsecten - herbivoren - trofische graden - brassicaceae - insect-plant relaties - multitrofe interacties - plant-herbivoor relaties - plants - insects - soil insects - herbivores - trophic levels - brassicaceae - insect plant relations - multitrophic interactions - plant-herbivore interactions
Het is bekend dat planten als verticale communicatiekanalen kunnen fungeren tussen onder-en bovengrondse plantetende insecten. Worteleters veroorzaken veranderingen in biomassa en de chemische samenstelling van de bovengrondse delen van een plant. Deze veranderingen kunnen de overleving, de groei en de ontwikkeling van bladeters beïnvloeden. In het promotieproject werd onderzocht of en hoe de wisselwerking tussen ruimtelijk gescheiden insecten beperkt is tot planteneters, dan wel uitgebreid kan worden naar hogere trofische niveaus zoals bijvoorbeeld parasitaire wespen, de natuurlijke vijanden van de plantenetende insecten. Tijdens de 20e Nederlandse Entomologendag (19 december 2008) is de eerste NEV dissertatieprijs uitgereikt aan dit proefschrift
Infochemical use in Brassica-insect interactions : a phenotypic manipulation approach to induced plant defences
Bruinsma, M. - \ 2008
Wageningen University. Promotor(en): Marcel Dicke, co-promotor(en): Joop van Loon. - [S.l.] : S.n. - ISBN 9789085049265 - 169
brassicaceae - verdediging - herbivoren - jasmonzuur - pieris rapae - pieris brassicae - fenotypen - plant-herbivoor relaties - brassicaceae - defence - herbivores - jasmonic acid - pieris rapae - pieris brassicae - phenotypes - plant-herbivore interactions
Plants have developed a range of strategies to defend themselves against herbivore attack. Defences can be constitutive, i.e. always present independent of attack, or induced, i.e. only elicited when the plant is under attack. In this thesis, I focused on induced chemical defence responses of plants and the response of associated insects to these phenotypic changes in plants. Herbivore attack is known to induce chemical defences in Brassicaceous plants. Using several elicitors and inhibitors of different steps of the signalling pathways underlying herbivore-induced plant responses, I studied how induced infochemicals affect interactions with associated insects.
Jasmonic acid (JA) is a key plant hormone in the octadecanoid signalling pathway known to be involved in herbivore-induced plant defences. Application of JA can induce plant responses that are similar, although not identical, to herbivore feeding. Two specialist herbivores of Brassicaceous plants, the butterflies Pieris rapae and P. brassicae, preferred to oviposit on non-induced plants over JA-induced plants. Development of P. rapae caterpillars was shown to be reduced, suggesting that oviposition avoidance on JA-induced plants is adaptive. The levels of glucosinolates, secondary metabolites of Brassicaceous plants that are used by Pieris butterflies as oviposition stimulants, could not explain the observed oviposition preference of the butterflies.
JA-induced changes in the plants also affected members of the third trophic level. Volatile emission of JA-induced plants attracted parasitoid wasps to the plants. Parasitoid attraction to JA-induced plants was shown to depend on dose and induction time. However, using JA to induce phenotypic changes had effects different from those induced by herbivores, both chemically and ecologically. Volatile emission of JA-induced and herbivore-induced plants differed; whereas JA-induced plants emitted larger amounts of volatiles, the parasitoids preferred herbivore-induced plants over JA-treated ones.
Early events in plant defence responses, involved in attacker recognition, are damage-induced modulations of ion channel activities resulting in ion imbalances. The fungal elicitor alamethicin, an ion channel-forming peptide mixture, was used to mimic early steps in defence responses. Alamethicin treatment increased attractiveness of plants to parasitoid wasps. Although volatile emission of alamethicin-treated plants was much lower, they were equally attractive as JA-treated plants. This indicates that quality rather than quantity of induced plant volatile blends is important to parasitoids.
Besides chemical elicitation of herbivore-induced responses, which is a widely applied approach, plant defence responses can also be chemically inhibited. This provides the opportunity to inhibit the rate of specific enzymatic steps in a signal-transduction pathway. Furthermore, visual cues associated with feeding damage can be present (and similar) in control- and inhibitor-treated plants. Phenidone is a compound that inhibits lipoxygenase, an enzyme catalyzing an early step in the octadecanoid pathway. Parasitoid attraction was reduced when the plants were treated with phenidone before infestation.
Also herbivore oviposition preference was shown to be affected by inhibition of this signalling pathway. Herbivores can differ in their oviposition preferences. I studied two specialist herbivores with different oviposition preferences: Pieris brassicae avoids oviposition on herbivore-induced plants, whereas Plutella xylostella prefers to oviposit on Pieris-infested plants. I showed that these preferences have a chemical basis and are dependent on octadecanoid signalling, since treatment with the lipoxygenase inhibitor phenidone eliminated herbivore-induced oviposition avoidance or preference.
Thus far, most of the studies on induced plant defences have been done with vegetative plants. However, since reproduction and defence are both processes that require energy and nutrients, this could result in a trade-off. Herbivore feeding on leaves, flowers or roots is known to affect pollinator visitation, but the mechanisms mediating this change have not been addressed. Effects of induction with JA on nectar secretion and pollinator visitation to flowers were investigated. JA-induced plants secreted less nectar, but the sugar concentrations did not change. Also visitation of honeybees and syrphid flies did not change upon JA induction.
These results show the complexity of induced plant defence responses and the variety of behavioural responses of insects on different trophic levels. Combining the phenotypic manipulation approach to induced plant defences, as used in this thesis, with molecular genetic techniques and building on recent developments in plant biochemistry provides a promising way forward towards enhanced understanding of the intricate interactions between plants and insects.
Diploid apomicts of the Boechera holboelli complex display large scale chromosome substitutions and aberrant chromosomes
Kantama, L. ; Sharbel, T.F. ; Schranz, M.E. ; Mitchell-Olds, T. ; Vries, S.C. de; Jong, J.H.S.G.M. de - \ 2007
Proceedings of the National Academy of Sciences of the United States of America 104 (2007). - ISSN 0027-8424 - p. 14026 - 14031.
in-situ hybridization - gene-expression - pennisetum-squamulatum - cenchrus-ciliaris - arabis-drummondii - b-chromosome - brassicaceae - evolution - arabidopsis - apomixis
We conducted a cytogenetic study of sexual lines of Boechera stricta and Boechera holboellii (2n = 14) and seven diploid apomictic accessions of their interspecific hybrid Boechera divaricarpa and B. holboellii (2n = 14 or 15). By studying chromosome morphology, rDNA repeats, genome painting, male meiosis, pollen morphology, and flow-cytometry seed screens, we revealed an unexpected plethora of chromosome forms, pairing behavior, and hybrid composition in all apomictic lines. Genome painting demonstrated that the apomicts are alloploid with variable numbers of B. stricta and B. holboellii-like chromosomes. We assume that large-scale homeologous chromosome substitutions took place in the apomictic hybrids that resulted from recurrent diploid-polyploid transitions through restitutional meiosis and polyploicly-diploid transitions through reductional meiosis. A second peculiarity was the presence of a largely heterochromatic chromosome (Het) in all apomictic accessions (2n = 14 and 15) and an additional smaller chromosome (Den in the aneuploids (2n = 15). Both chromosomes share repetitive pericentromere repeats with those from the sexual B. stricta, suggesting that they originated from this species. Pairing and behavior at meiosis I of the Het share features with both Y and B chromosomes and suggest that the Del arose from a translocation event or homeologous recombination between a B. holboellii (or related taxon) and a B. stricta chromosome. Based on its presence exclusively in apomictic accessions, we propose that the Het chromosome plays a role in the genetic control of apomixis.
Kool in Nederland : geschiedenis van teelt en veredeling
Pistorius, R. ; Veldhuyzen van Zanten, J. ; Arron, R. ; Centrum voor genetische bronnen (CGN) in Nederland- -, - \ 2006
Wageningen : Wageningen UR - 10
brassicaceae - koolsoorten - nederland - plantenveredeling - teelt - groenten - agrarische geschiedenis - brassicaceae - cabbages - netherlands - plant breeding - cultivation - vegetables - agricultural history
QTL analysis of cadmium and zinc accumulation in the heavy metal hyperaccumulator Thlaspi caerulescens
Deniau, A.X. ; Pieper, B. ; Bookum, W.M. ten; Lindhout, P. ; Aarts, M.G.M. - \ 2006
Theoretical and Applied Genetics 113 (2006)5. - ISSN 0040-5752 - p. 907 - 920.
linkage maps - arabidopsis-thaliana - aflp markers - construction - populations - tolerance - crosses - genes - brassicaceae - transport
Thlaspi caerulescens (Tc; 2n = 14) is a natural Zn, Cd and Ni hyperaccumulator species belonging to the Brassicaceae family. It shares 88% DNA identity in the coding regions with Arabidopsis thaliana (At) (Rigola et al. 2006). Although the physiology of heavy metal (hyper)accumulation has been intensively studied, the molecular genetics are still largely unexplored. We address this topic by constructing a genetic map based on AFLP® markers and expressed sequence tags (ESTs). To establish a genetic map, an F2 population of 129 individuals was generated from a cross between a plant from a Pb/Cd/Zn-contaminated site near La Calamine, Belgium, and a plant from a comparable site near Ganges (GA), France. These two accessions show different degrees of Zn and, particularly, Cd accumulation. We analyzed 181 AFLP markers (of which 4 co-dominant) and 13 co-dominant EST sequences-based markers and mapped them to seven linkage groups (LGs), presumably corresponding to the seven chromosomes of T. caerulescens. The total length of the genetic map is 496 cM with an average density of one marker every 2.5 cM. This map was used for Quantitative Trait Locus (QTL) mapping in the F2. For Zn as well as Cd concentration in root we mapped two QTLs. Three QTLs and one QTL were mapped for Zn and Cd concentration in shoot, respectively. These QTLs explain 23.8¿60.4% of the total variance of the traits measured. We found only one common locus (LG6) for Zn and Cd (concentration in root) and one common locus for shoot and root concentrations of Zn (LG1) and of Cd (LG3). For all QTLs, the GA allele increased the trait value except for two QTLs for Zn accumulation in shoot (LG1 and LG4) and one for Zn concentration in root (LG1).
The heavy metal hyperaccumulator Thlaspi caerulescens expresses many species-specific genes, as identified by comparative expressed sequence tag analysis
Rigola, D. ; Fiers, M.W.E.J. ; Vurro, E. ; Aarts, M.G.M. - \ 2006
New Phytologist 170 (2006)4. - ISSN 0028-646X - p. 753 - 765.
arabidopsis genome - zn hyperaccumulator - tolerance - plants - accumulation - model - brassicaceae - transporter - populations - accessions
¿ Thlaspi caerulescens is a natural zinc (Zn), cadmium (Cd) and nickel (Ni) hyperaccumulator and an emerging plant model species to study heavy metal hyperaccumulation and tolerance. This paper describes the analysis of the first expressed sequence tag (EST) collection from T. caerulescens. This collection is a new resource to unravel the molecular basis of plant metal homeostasis, tolerance and hyperaccumulation. ¿ In total, 4289 ESTs were generated originating from Zn-exposed root and shoot tissues, leading to 3709 T. caerulescens assembled partial cDNA sequences (unigenes). ¿ In comparison to Arabidopsis or other publicly available plant sequences, a fraction of c. 8% of the T. caerulescens unigenes (TcUGs) had no significant similarity with any known DNA sequence and, so far, these sequences are T. caerulescens specific. Three per cent of the TcUGs correspond to Arabidopsis thaliana orthologues that, as yet, have not been found to be expressed. ¿ The T. caerulescens transcriptome generally relates very well to the A. thaliana transcriptome, although, compared with other closely related species, a relatively large number of T. caerulescens-specific transcripts were found. T. caerulescens also expresses a relatively large number of genes which are expressed at a very low level in A. thaliana.
AFLP markers for the R-gene in the flea beetle, Phyllotreta nemorum, conferring resistance to defenses in Barbarea vulgaris
Breuker, C.J. ; Victoir, K. ; Jong, P.W. de; Meijden, E. van der; Brakefield, P.M. ; Vrieling, K. - \ 2005
Journal of Insect Science 5 (2005). - ISSN 1536-2442 - p. 38 - 38.
atypical host-plant - plutella-xylostella - diamondback moth - lucilia-cuprina - asymmetry phenotype - diazinon resistance - culex-pipiens - identification - brassicaceae - specificity
A so-called R-gene renders the yellow-striped flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) resistant to the defenses of the yellow rocket Barbarea vulgaris R.Br. (Brassicacea) and enables it to use it as a host plant in Denmark. In this study, genetic markers for an autosomal R-gene, inherited as a single, dominant locus in flea beetles from the Danish locality "Kværkeby" are described, and a genetic linkage map around this particular R-gene is constructed, using the technique of AFLP (Amplified Fragment Length Polymorphism)