Eleven new projects in green top sectors

26 November 2019

The NWO Domain Science Board has approved eleven proposals in the programme Graduate School Green Top Sectors. Five projects fall within the Top Sector Horticulture and Propagation Materials and six projects in the Top Sector Agri-Food. Within this programme, excellent master students can, in collaboration with knowledge institutions and companies, submit a proposal for their PhD research

Projects within the Top Sector Horticulture & Starting Materials

Spiralling into Control: Shaping Architecture in Arabidopsis and Cucumber
Dr Viola Willemsen, PhD candidate Merijn Kerstens, Wageningen University and Research
Cucumber fruits are important global economic and gastronomic assets. Unfortunately, the emergent high-wire cultivation system that yields the most consistent high-quality cucumbers is extremely labour-intensive. The long internodes of the plant require almost daily coiling of the bottom section of each stem, and manual removal of leaves in this area. Additionally, the radial orientation of the leaves is spiral, which impedes access to the fruits during harvesting for both human and robot alike. I propose an innovative project to stably alter cucumber phyllotaxis, here defined as the vertical and horizontal arrangement of lateral organs, by exploiting the genetics of the Arabidopsis thaliana model system. This project investigates a fundamental biological problem with a promising application in cucumber breeding, and in other crops exhibiting spiral phyllotaxis.

REJUVENATOR: the potential of regulating plant longevity
Prof. Remko Offringa, PhD candidate Thalia Luden, Leiden University
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.
This research will provide fundamental insights into the regulation of vegetative development, which can be applied in breeding of both ornamental and food crops.

Towards sustainable processing of organic debris from large-scale rose farming in Kenya
Dr Albert Tietema, PhD candidate Evy de Nijs BSc, University of Amsterdam
The limited usage of rose debris as compost makes large-scale rose farming far from a sustainable circular economy, in which all waste products are reused. Composting of rose debris is hampered by unfavorable chemical and physical properties of specific parts of the rose debris, like high lignin content in the stems and high phenolic compounds in the leaves. In this project, we look for more optimal mixtures of rose debris compounds with other organic waste based on their chemical and physical properties. These mixtures will be tested in a large field experiment on a rose farm in Kenya. With this project, we will provide rose farmers with a recipe on how to transform their production chain towards a more circular economy by securing a closed cycle of resources.

Targeted DNA-Recombination in Somatic Cells of Plants
Prof. Richard Visser, PhD candidate Jillis Grubben, Wageningen University
Plant breeders improve crops by incorporating traits from wild relatives into cultivars, using crosses, leading to introgression of resistances to (a)biotic stresses. Although breeders know for these crosses their starting material and which progeny they desire, they have no control over recombination positions. Therefore, they generate large populations, discarding >99% of these progenies. Another difficulty is that inversions in chromosomes hardly recombine. If a resistance gene is located in an inversion, it is impossible to remove unwanted genes -leading to linkage drag- from the inversion by breeding. This project is aimed at solving these issues by targeted recombination at predefined chromosomal positions in somatic cells. This approach enables breeders to introduce resistance genes from wild cultivars, preventing linkage drag, even from large inversions, thus removing the necessity of backcrosses. This is an innovative approach, supporting durable plant production.

The essence of non-photochemical quenching in higher plant photosynthesis
Prof. Mark Aarts, PhD candidate Louise Lea Logie, Wageningen University & Research
Plants are dependent on light energy to convert CO2 into carbohydrates through photosynthesis. However, part of the energy is lost as heat through non-photochemical quenching (NPQ). For optimal carbohydrate production, a plant should be able to rapidly increase NPQ when there is excess light and rapidly decrease upon lower irradiance. The aim of this PhD project is to identify the genes underlying the natural genetic variation in NPQ, such that the genes can be used to increase photosynthetic efficiency. Finding the genes underlying NPQ and consequently photosynthesis efficiency will answer some of the most important fundamental questions about photosynthesis and will be instrumental in guiding plant breeding companies to breed for improved photosynthesis as a so far unexplored way to increase crop yield.

Projects within the Top Sector Agrifood

Enhancing Brassica seed yield and quality: understanding the role of herbivory in outcrossing through pollination and self-incompatibility
Dr Erik H. Poelman, PhD candidate Hanneke Suijkerbuijk, Wageningen University & Research
Insect herbivores can cause great damage to plants in the field, with disastrous consequences for plant fitness in terms of seed yield and quality. The aim of this project is to understand how herbivory affects outcrossing and subsequently seed yield and quality, through its effect on pollinators and self-incompatibility mechanisms in Brassica rapa. I will study how herbivory affects pollen acceptance and self-incompatibility at different stages of flower lifetime, and how this impacts seed yield and quality. On the mechanistic level, I will unravel molecular mechanisms responsible for plasticity in self-incompatibility under herbivore-stress. My project will yield novel fundamental insights in how plants integrate defence and reproduction strategies and contribute to mechanistic understanding of self-incompatibility, pollination and outcrossing for plant breeding.

Putida for plastics
Prof. Vítor Martins dos Santos, PhD candidate María Martín Pascual, Wageningen University
A major challenge of the 21st century is to meet rising global market demand for building blocks and polymers while ensuring environmental sustainability. White biotechnology has emerged as a promising green alternative, by relying on improved microorganisms for fuels and production of chemicals. Yet, substantial improvements are required to enable its economically feasible application to industrials processes. This project aims at tackling essential aspects of the metabolism and regulation of the microbe Pseudomonas putida to render it robust for industrial production of FDCA, a key precursor for the biodegradable polyethylene furanoate, which can become a major substitute of plastic.

Towards sustainable production of natural food additives: How can biotechnology help?
Dr Maria Suarez Diez, PhD candidate Sara Moreno Paz, Wageningen University and Research
Biotechnology uses microorganisms as small factories to efficiently obtain a variety of natural products:
bioplastics, vitamins, aromas etc. Since designing cell factories is a long, difficult task, we will accelerate and
facilitate it creating a workflow that integrates biology, computer science and engineering. This strategy
will be applied to meet consumer demand towards natural food additives avoiding inefficient plant
extraction, as 1 kg of these compounds requires tons of fruits or vegetables. Thus, cell factories are
presented as an alternative for production of natural colorants contributing to the challenge of creating
food chains where people and sustainability are the main focus.

PRECERPHYT – Food PREservation by coupling of CEReal PHYTochemicals: Size matters!
Prof. Jean-Paul Vincken, PhD candidate Annemiek van Zadelhoff, Wageningen University and Research
Increased production and consumption of low-alcohol and non-alcoholic beer, along with several other trends in food, have led to demand for new, natural approaches to food preservation. The proposed research is aimed at clean label preservation of such beers by developing a generic strategy to generate antimicrobial compounds from phytochemicals. Coupling of phytochemicals by oxidative enzymes is a tool used by various plant species to enhance the antimicrobial activity of their defence compounds. The knowledge obtained from these experiments will be applied to screen other cereals and cereal waste streams (e.g. from the beer industry) for valuable precursors that can be valorised with an oxidative enzyme treatment. This research will add to our toolbox to generate natural food preservatives from plants and it will contribute to our understanding of plant defence mechanisms.

Human milk: a shaping factor of the infant microbiome
Dr C. Belzer, PhD candidate Athanasia Ioannou, Wageningen University & Research
Breastfeeding is the best infant nutrition but in Europe only 25% of children are exclusively breastfed for the recommended 6 moths. Alternative feeding options, like infant formula, are constantly improving to mimic human milk. However, formula-fed infants demonstrate differences in their microbiome compared to the breastfed infants. Certain sugars present of human milk drive optimal gut microbiota composition. We aim to unravel how microorganisms in the infant gut collaboratively utilize these sugars and form healthy microbiota. The results of this project can help improve infant formula thus being a step towards providing all infants with the best possible nutrition.

OLEOX - OLEOsome architecture to prevent lipid OXidation
Dr Marie Hennebelle, PhD candidate Lorenz Plankensteiner, Wageningen University
Preventing lipid oxidation of lipid-based products while meeting the increasing demand from consumers for natural and sustainable products, who says it is an impossible mission? It seems that plants already found the solution by storing their lipids in highly specialized and stable structures called oleosomes. Now, we need to understand how it works, which is the objective of this project. Lipid oxidation will be monitored in oleosomes with different composition and under different environmental conditions to characterize which properties confer them their oxidative resistance. The knowledge gathered will help broaden the field of applications for oleosomes, as a natural ingredient and develop nature-inspired emulsion systems.

Source: NWO