PhD candidate, Molecular Plant Physiology, Utrecht University Project title:Plants grow with a foot on the brake: How a single kinase represses acclimation to high and low temperatures signals.
About my research Plants are sensitive to small changes in ambient temperature and respond to both cold and warm temperatures by adjusting their growth, architecture and physiology. Acclimation to warm ambient temperatures is called thermomorphogenesis and includes the elongation of the stem and petioles. Together with an upward leaf movement this leads to an open rosette structure that aids the cooling capacity of plants. On the other end of the temperature spectrum cold stress can cause severe irreversible damage to plants. However, plants can become cold tolerant after an acclimation period at low temperatures by a process called cold acclimation. Although the molecular regulation of thermomorphogenesis and cold acclimation are increasingly well understood, none of the identified molecular factors have an apparent role in acclimation to both cold and warm ambient temperatures, despite being part of the same temperature continuum.
We have identified a kinase that functions in both thermomorphogenesis and cold acclimation pathways. A knockout of this kinase leads to an increased thermomorphogenesis and cold acclimation responses. Therefore this kinase could be considered a universal molecular break on acclimation to different ambient temperatures. I aim to unravel how this kinase simultaneously controls thermomorphogenesis and cold acclimation by using (phospho)proteomic and transcriptomics approaches.
Judit Nadal Bigas, secretary
PhD student, Molecular Biology, Wageningen University & Research Project Title: ‘The art of multitasking: flowering time genes and their relation with seed dormancy‘
About my research The life cycle of annual plants can be divided in different phases that include vegetative growth, reproductive adult phase, seed set and senescence. Since plants are organisms that cannot migrate when the external conditions are not favorable, the transition between the different life phases needs to be strictly controlled. In fact, the basis of an adaptive life relies on the ability to respond in different ways to environmental and/or internal cues in different developmental stages. From all the external variables, temperature is one of the strongest signals that plants sense and adapt to. For this reason, the current context of climate change is altering the timing of crucial transitions such as the transition to flowering.
In this project we aim to study two temperature-regulated traits, flowering time and seed dormancy, that have been separately researched for several years but that have been recently proposed to be interconnected. Both traits are fundamental for the reproductive success and survival of any plant specie. Therefore, knowledge of plant plasticity and adaptation to temperature fluctuations is vital for a sustainable global food security. In my PhD project we will combine techniques such as CRISPR-Cas9, molecular cloning or yeast-two-hybrid to understand the complex multitasking role of temperature-responsive key regulatory members that link timing of flowering and seed dormancy.
Sietske van Bentum, council member
PhD candidate, Plant Microbe Interactions, Utrecht University Project title: Selecting soybean-specific consortia of beneficial microbes for sustainable yield improvement
About my research Current agricultural practices call for innovative solutions towards more sustainable crop production. Reducing the use of fertilizers and pesticides is part of this challenge, where a solution can be found in plant-beneficial microbes that promote plant growth and health. Plants are able to recruit such beneficial microbes in the root environment upon infection, as shown recently in Arabidopsis thaliana infected with the oomycete Hyaloperonospora arabidopsidis or the bacterium Pseudomonas syringae. In my project, we study this disease-induced recruitment of beneficial microbes in soybean plants. We employ infection with different pathogens to select, isolate and characterize soybean-specific consortia of beneficial microbes. To explore the mechanisms underlying this recruitment, metabolite profiles of soybean roots and exudates will be compared between healthy and diseased plants. By combining metabolite profiling with microbiome analysis, we aim to commercialize soybean-specific beneficial microbes, providing soybean growers with a novel biocontrol product effective in the field.
Ivo Gariboldi, council member
PhD candidate, Molecular Developmental Genetics, Leiden University Project title:Enhanced somatic embryogenesis by bacterial protein translocation
About my research Many plant species are dependent on sexual reproduction to reproduce. In zygotic embryogenesis the fusion of two sexual cells forms a diploid zygote and then develops into an embryo. Apart from sexual reproduction embryos can be formed asexually e.g. by induction in vitro in various plant tissues. The application of in vitro embryogenesis is widely accepted as a biotechnical tool in industry as well as academic research. In plant breeding somatic embryogenesis (SE) is a popular tool for clonal propagation. It has been shown that SE can be induced by overexpression of genes involved in embryogenesis. Since this relies on the modification of the plant genome, it is not suitable for plant breeding. In this work we will investigate the possibility to induce somatic embryos by translocation of various proteins involved in the induction of SE. Furthermore, we will try to better understand how the process of embryogenesis in induced by these proteins. This research might give more detailed knowledge on the role of certain proteins in embryogenesis induction and this could be eventually utilized in the field of plant breeding.
Irene van Grinsven, council member
PhD candidate, Virology, Wageningen University & Research Project title:Unraveling Tsw-mediated resistance and the interplay with the innate immunity modulator NSs of Tomato spotted wilt virus, a plant-infecting bunyavirus
About my research Tospoviruses are members of the arthopod-borne Bunyavirales, comprising one of the few genera whose members infect plants rather than animals. Tomato spotted wilt virus (TSWV), the type species of the tospoviruses, is one of the most important plant viruses worldwide with a large host range of more than 80 different plant families. Currently, two single dominant resistance (R) genes are available for commercial resistance breeding. The first, Sw5 from Solanum lycopersicon, confers resistance to TSWV and a few additional tospoviruses. The second, Tsw, from Capsicum chinense confers resistance to TSWV only. Although their mode of action is still largely unknown R genes, besides the actual resistance response, trigger a concomitant hypersensitive response. This is based on a programmed cell death and leads to the formation of necrotic spots that prevents further spread of the pathogen from the primary site of infection. Recently we have identified the viral NSs protein as the effector of the Tsw-mediated programmed cell death response. This protein, moreover, also suppresses antiviral RNAi, the first line of the innate immunity response against viruses in plants and insects. This project aims to support developments towards durable resistance against TSWV by unraveling the resistance mechanism of Tsw, and understand how NSs (in)directly triggers the intracellular innate immunity sensor Tsw leading to resistance and modulates innate immunity responses in its plant host and insect vector.
Zhang Jiang, council member
PhD candidate, Plant Ecophysiology / Molecular Plant Physiology, Utrecht University Project title: Physiological genomics of plant responses to multiple abiotic stresses
About my research Plants often encounter environmental stresses simultaneously or sequentially as stresses rarely occur in isolation. Responses to multiple stresses are often distinct than either stress applied in isolation. It is therefore vital to characterize the mechanisms of plant acclimation to multiple abiotic stresses. In my project we analyze two stress combinations: high ambient temperature + drought and a sequential stress: flooding followed by drought, both of which come up frequently and cause severe destruction of crops. The physiological, morphological and phenological responses to these stresses was characterized in the Arabidopsis thaliana. Based on this information, a transcriptome approach will be used to identify underlying genes and molecular processes controlling relevant traits. Finally candidate genes that potentially contribute to stress acclimation will be identified and functionally validated. Ultimately the identification of plant traits and regulatory networks mediating acclimation to multiple stresses will be very relevant towards the breeding of stress-tolerant crops with sustained yields.
Jasper Lamers, council member
PhD candidate, Plant physiology, Wageningen University & Research Project title: Unravelling the elusive sodium perception mechanism in plants
About my research Soil salinization leads to massive decreases in crop yield and threatens 7% of arable land and 30% of irrigated soil. Plants experience two types of stress due to increased sodium concentrations in the soil. The immediate effect is the reduced water uptake by the root. Later on, sodium accumulation in the plant inhibits essential cellular processes like photosynthesis. Over the years, it has been proven that plants respond to sodium in a specific way that is not observed by solely osmotic stress or application of other ions. Meaning that sodium ions must be perceived specifically by the plant. The existence of such proteins is not surprising as studies already showed sodium sensors in mammals, bacteria and nematodes. However, no homologues have been found in plants. Although, studies have identified responses within 10 seconds after sodium application, the sensing mechanism and earliest responses remain elusive and finding it will be my main goal.
Lena Maas, council member
PhD candidate, Molecular Biology, Wageningen University & Research Project title: Transient Induction of Plant Regeneration
About my research One of the major bottlenecks in plant breeding programs is the recalcitrance for in vitro embryogenesis in some species or genotype of common crops, which limits the use of modern biotechnology tools. Progress in tissue culture procedures by using growth regulators and culture media combinations have been time consuming and inefficient for a large number of crops, which is why there is an urgent need to develop novel, generic tools to improve plant regeneration processes in a germplasm-independent manner. Embryo-expressed transcription factor like the AP2 domain protein BABY BOOM and CAAT-box binding factor LEAFY COTYLEDON1 have been used to enhance plant regeneration in a range of crops when expressed from a constitutive promoter, resulting in transgenic lines.
This project aims to examine the extent to which BBM and LEC1 can be used to transiently promote in vitro regeneration without genomic integration of nucleic acids and without genomic DNA mutation. Different approaches will be used to transiently induce BBM/LEC1 protein in plant cells. One approach is to use cell-penetrating peptides to introduce those proteins into the plant. Additionally, we aim to activate endogenous BBM/LEC1 gene expression by using CRISPR-dCas9 technology and small chemical compounds. The overall focus lies on improving in vitro regeneration in haploid embryo induction for doubled-haploid production as well as somatic embryogenesis for clonal propagation.
Davy Meijer, council member
PhD candidate, Entomology, Wageningen University & Research Project title: LEDs make it resilient!
About my research The introduction of light emitting diode (LED) technology in horticulture has contributed greatly to improving both productivity and sustainability in greenhouse crop production. Their biggest advantage for horticulture is their ability to tightly control the spectral composition of the light. Over the past decades, our knowledge on how different wavelengths of light influence plant growth and development has increased tremendously. Using LEDs, this knowledge is now being exploited to increase the yield and quality of greenhouse crops.
The next step is to use LEDs for integrated pest management (IPM). Light quality is an important mediator of plant stress tolerance and can play an important role in plant-herbivore interactions. In this project, we will look at the effects of different wavelengths of light on the plant’s immune responses to herbivore feeding, to the attraction and efficiency of biological control agents and to the feeding behavior and reproduction of herbivore pests. We aim to find light quality-effects that boost the plant’s natural defenses, while at the same time maintaining productivity and quality.
Daniel Moñino Lopez, council member
PhD Candidate, Plant Breeding, Wageningen University and Research Project title:Potato genome editing for late blight resistance
About my research Late blight, caused by the oomycete Phytophthora infestans, is the most devastating disease in potato. Moreover, most of the currently used elite potato cultivars are susceptible to late blight. In order to control P. infestans, growers rely on biocide application, which is expensive, time consuming and non-environmentally friendly. In many wild potato relatives, resistance (R) genes have been identified to confer resistant against P. infestans. The introgression of R genes from wild potato relatives into susceptible potato cultivars is very laborious and most of the times negative traits, such as lower yield or higher alkaloid content complicate the process. As an alternative, more advance techniques such as CRISPR-Cas have been developed in the last decade to modify plant genomes. In this project, we focus on the R gene editing of susceptible potato varieties to make them resistant to P. infestans. Additionally, we want to optimise and develop new genome editing approaches which will allow us to modify very precisely the target sequence. Therefore, this research also contributes to the general knowledge and to the discovery of new potential applications of genome editing for any plant species.
Martha van Os, council member
PhD candidate, Plant Physiology, Swammerdam Institute of Life Sciences, University of Amsterdam Project title:Scensitive nature: Green leaf volatile perception in plants
About my research Green leaf volatiles (GLVs) are an integral part of plant defense against biotic and abiotic stresses. They are emitted within seconds of damage to photosynthetic tissues and are known for their smell of cut grass. GLVs can have a direct or indirect defensive effect by repelling herbivores or pathogens or by attracting predatory insects. They also serve as within- or between-plant signals that either induce or prime plant defenses. However, it is still unknown how plants perceive volatile compounds and how the specificity of the volatile signal is transduced in the plant.
This research focuses on the GLV Z-3-hexenal and its isomer E-2-hexenal, as they are among the most abundant and influential volatiles in the GLV cluster. I aim to elucidate receptor candidates in Arabidopsis with forward genetics screens and proteomics approaches to further study plant GLV perception and implications for plant’s self-recognition and interactions with herbivorous insects and pathogens. Additionally, (3Z):(2E)-hexenal isomerases were recently identified in both insects and plants that convert Z-3-hexenal to E-2-hexenal. This change in the Z-3-/E-2-ratio affects the behavior of insects like foraging predators and host-seeking herbivores, and is expected to also alter plant defense response. For this part of my research I use potato, a crop species that unlike Arabidopsis has high isomerase activity, to study the role of hexenal isomerase in plants’ adaptive ability interact with its environment and its effect on ecological relations between plants and insects.
Mandy Ravensbergen, council member
PhD candidate, Wageningen University & Research Project title:Understanding the molecular biology of plant-virus relationships: Towards sustainable, Integrated Virus Management Strategies
About my research
Tomato yellow leaf-curl virus (TYLCV) is a single-stranded DNA virus causing devastating yield loss in crops; notably, it has been reported as the most damaging pest to tomato cultivation. The virus is found in presence of its vector, the whitefly Bemisia tabacii, in tropical and subtropical regions all over the globe. Due to the rising temperature world-wide, which increases the chance of this vector surviving outside the greenhouse in temperate regions, the likelihood of this pest establishing in temperate regions as well increases. Resistance to TYLCV is conferred by amongst others the resistance gene Ty-1. Ty-1 is an RNA-dependent RNA polymerase (RDR) belonging to the γ class. In general, very little is known on the γ class, although members of the α class are involved in RNA interference, a general viral defense pathway. Understanding the Ty-1 mediated resistance mechanism could lead to the usage of this underlying mechanism to protect more plants from viruses like TYLCV.
Max Frencken, council member
PhD candidate, Plant Systems Physiology, Radboud University Project title:HeatGenes: toward a generic genetic framework for plant reproductive heat-tolerance.
About my research
As a consequence of climate change, weather extremes, such as heat waves, are expected to become increasingly frequent. As sessile organisms, plants are affected by these events in both the vegetative and reproductive phase. Heat stress during reproductive development leads to catastrophic yield loss in many food crops, imposing pressure on future food security. In the past, studies have shown during the reproductive stage, male gamete development is the most sensitive to high temperatures. However, past studies mostly focused on short extreme high temperature effects (heat shock) and few have investigated the effects of heat wave-like long-term mild heat (LTMH).
This is the fundamental drive of the HeatGenes project, a NWO (TTS)-funded study, performed in cooperation between the Radboud University and multiple companies involved in plant breeding. We expect the genetic basis of the reproductive heat-tolerance phenotype to be well-conserved among angiosperms. By performing genome-wide association studies (GWAS) on multiple plant species (e.g. Arabidopsis thaliana, tomato, common bean, carrot, and Brassica sp.), we are identifying quantitative trait loci (QTLs) and candidate genes associated with the heat-tolerance phenotype. A study in Arabidopsis thaliana will provide insights on molecular/physiological pathways involved, while studies in various commercially valuable crop species will directly provide germplasm for heat-tolerant lines. Additionally, we will develop reproductive heat-tolerance screening assays for plant species for which none existed previously.
Thalia Luden, council member
PhD candidate, Plant Developmental Genetics, Leiden University Project title:Rejuvenator: the potential of regulating plant longevity
About my research
Polycarpic plants flower more than once in their lifetime, and need to resume vegetative development after flowering to continue growth and prepare for the next flowering cycle. Monocarps, on the other hand, do not resume this vegetative growth and die after flowering. Control of vegetative growth is of major agri- and horticultural interest, as it can help to improve the quality of leafy vegetables and the yield and quality of cuttings and flowers. Recently, the Arabidopsis REJUVENATOR/AHL15 transcription factor gene has been identified as a key regulator of vegetative growth. While striking phenotypes have been described in plants with altered RJV/AHL15 expression, the molecular mechanism of RJV/AHL15-induced vegetative growth remains unknown.
With this research, we aim to unravel the regulatory pathways surrounding RJV/AHL15 to gain understanding of vegetative development in plants. This will be done by studying different effects of RJV/AHL15 activity in Arabidopsis thaliana such as its effect on the transcriptome and its role in changing the epigenetic landscape of the genome, and the natural variation of RJV/AHL15 in different Arabidopsis ecotypes and other plant species. Understanding how vegetative development is regulated in plants will not only help breeding efforts in commercial crops, but also shed light on how the diversity of life history strategies has evolved in plants.
Milan Plasmeijer, council member
PhD candidate, Plant Physiology, University of Amsterdam and Green Biotechnology, Inholland University of Applied Sciences Project title: Biosynthesis, regulation and transport of floral volatile benzenoids and phenylpropanoids; a CRISPR-approach
About my research
Many plants are dependent on insects for their reproduction and need to attract these pollinators to their reproductive organs. Flower morphology, pigmentation and scent emission all have major impact on pollinator behavior. In my research, we focus on the emission of floral volatile benzenoids and phenylpropanoids (FVBPs) in model organism Petunia hybrida, which attract nocturnal hawkmoths. Scent emission in P. hybrida is tightly controlled and strictly regulated to coincide with the activity of the hawkmoths, which are active during nightfall. Our group has identified candidate genes that are involved in the circadian regulation and biosynthesis of FVBPs, and genes that are involved in internal transport of precursors to feed in the biosynthetic pathway of FVBPs. By setting up different CRISPR-based gene editing protocols for Petunia, I will make knock-outs and knock-downs to further characterize the role of these genes in FVBP biosynthesis. In addition, I will specifically modify promoter elements of the circadian R2R3-MYB transcription factor ODO1 to understand their role in circadian emission of FVBPs. We will thus extend the current comprehensive model of FVBP biosynthesis, which may be used for several commercial purposes (eg. production of economically important metabolites, bringing back scent in crops that have lost scent during domestication, improving flower scent and longevity).