Research Group: Plant Nutrition

Nanofertilization of plants

The use of nanotechnology to fertilize plants is rapidly advancing. Nanofertilization holds a range of potentials to increase the efficiency of both soil and foliar fertilization. The mobility and dissolution of fertilizers in the soil can be tailored and optimized to better match the requirements of plants and to reduce nutrient immobilization by soil minerals and microbes. Moreover, the foliar uptake and translocation of nutrients applied to the leaf surface can be improved using nanofertilizers to allow a timely and efficient restoration of nutrient functionality. However, in order to advance the development and application of nanofertilizers we still lack a better mechanistic understanding of nanoparticle uptake, translocation, dissolution and assimilation of the derived mineral ions in plant metabolism. Currently we are running three different research projects where we study these processes in cereal crops and apply the findings to synthesize nanofertilizers with an improved Mn and P use efficiency. Thus, we strive to solve an acute and significant problem in agriculture where fertilizers currently are used way to inefficient.

Contact: Søren Husted (shu@plen.ku.dk)

Plant uptake and transport systems of the micronutrient manganese in barley
We study the Mn uptake systems in roots and the functional role of Mn in photosystem II. We have made the observation that barley genotypes differ tremendously in their tolerance to Mn deficiency and we explore the mechanisms underlying this observation. Our objective is to provide the basis for breeding plants with a better fitness to tolerate growth in soils with a sub-optimal availability of Mn.

Contact: Søren Husted (shu@plen.ku.dk)

Impacts of physical root barriers and passage cells on nutrient uptake and translocation in plants

Only 40-70% of most essential macro nutrients applied to plants is removed with the harvested products. Such low values represent a major challenge to agriculture in order to reduce nutrient losses and improve the sustainability of fertilizer use. Research in this area has hitherto mainly been devoted to studies of root architecture and identification of gene and protein networks. However, roots are characterized by a remarkable physical plasticity in response to environmental impacts like drought, salt stress and nutrient availability. This plasticity is mainly reflected in passage cells and root barrier formation, which include deposition of hydrophobic lignin between adjacent endodermal cells (i.e. the Casparian strip; CS) followed by deposition of waxy lipid polyesters (suberin) between the cell wall and the plasma membrane of the individual endodermal cells. Very little is known about these root barriers and how they affect t nutrient uptake and translocation. In this project we will demonstrate that root barriers and passage cells are vital components in order to provide a complete biological model of ion uptake and translocation in crop production.

Contact: Daniel Persson (dap@plen.ku.dk)

Silicon – boosting the natural stress tolerance of plants
The overall aim is to quantify foliar silicon uptake and deposition from different Si sources, viz. soluble, stabilized (organically-bound) and nanoparticle-bound Si. This will be achieved by application of new technologies in ionomics and bioimaging. The relative importance of foliar entry pathways such as trichomes, stomata and cracks in anticlinal cell walls will be determined together with the pattern of Si deposition during critical growth stages. The interactions between root-absorbed Si and foliarly-applied Si will be determined, together with the interactions with other nutrients, particularly nitrogen. The molecular- physiological responses to Si provision in terms of photosynthesis, water and nutrient use-efficiency will be investigated. The project will deliver novel biological information about foliar Si absorption, its deposition, interaction with other elements and physiological impacts.

Contact: Jan K. Schjoerring (jks@plen.ku.dk)

Plant zinc deficiency sensing and regulation, and F-bZIP transcription factors
Zinc (Zn) is an essential micronutrient due to structural and catalytic roles in many proteins, and its deficiency in agricultural soils, crops and in cereal-based diets is a major global problem. Understanding the molecular basis of plant response to zinc deficiency can help improving crop zinc-use-efficiency, biofortification and adaptation to zinc deficient soils. We study the molecular mechanisms of Zn deficiency sensing and regulation, anchored at the Arabidopsis F-bZIP transcription factors. We investigate the mechanisms underlying the F-bZIP-regulated Zn deficiency response in plants, from molecular to organism levels, including the Zn-sensor function, the role of F-bZIP target genes and modulation of F-bZIP transcription factor’s activity to impact plant Zn accumulation and Zn use-efficiency traits. Our work includes exploring the evolutionary conservation of the F-bZIP regulatory network in land plants, and translational approaches to crops.

Funded by the Danish Council for Independent Research (YDUN project: 2015-2019; Research Project 2: 2020-2023) and Novo Nordisk Foundation (Biotechnology-based Synthesis and Production Research Project: 2019-2022).

Contact: Ana Assuncao (agla@plen.ku.dk)

Rock-P (Nanosized and functionalized rock phosphate as a novel high-efficiency fertilizer for cereal crops) Danmarks Frie Forskningsfond |Starting date: 01-10-2020 End Date: 30-09-2024 6.200.000 kr.

Inefficient use of fertilizer phosphorus (P) has over the past 75 years resulted in an enormous accumulation of P in agricultural topsoil, but with inadequate availability to crops due to chemical fixation and microbial immobilization of orthophosphates (Pi). This calls for an acute rethinking of P management in Danish agriculture to ensure a more sustainable use of P. The proposed project will improve nutrient use efficiency of P. We will establish the scientific basis for development of a new generation of nanosized and functionalized P fertilizers with low adsorption to soil and a much-improved bioavailability to plants. The Rock-P project will deliver an imporved mechanistic understanding of how P containing NPs can be functionalized in order to trigger internalization by root cells. Knowledge to the processes controlling the subsequent translocation and dissolution of Pi from the internalized NPs in order to support P dependent metabolism of plants. Procedures to nanosize and chemically modify rock phosphates to reduce chemical fixation in soil and increase uptake efficiency in cereal crops

LIPOSOME (Liposome-based foliar fertilization to boost climate friendly productivity and quality in high-value crops with resistant hydrophobic cuticles) Danmarks Innovationsfond Project start date: 01-01-2021 Project end date: 31-12-202529.745.690 kr.

Crops take up a minor fraction of most soil-applied nutrients. This wasteful practice is a fact that burdens plant producers with costs, unnecessarily large carbon footprints and eutrophication of the aquatic environment. Foliar fertilization bypasses chemical and microbial fixation in the soil system and may therefore eliminate most of the disadvantages linked to classical soil-based fertilization. Foliar fertilization is an effective and well-established agricultural practice worldwide for a range of essential plant nutrients and crop species. However, for some nutrients, the efficiency is still very poor and for some crops the procedure is so inefficient that foliar fertilization is little used.

In this project, we will explore these resistant pathways in order to circumvent them, by utilizing the most recent advances within plant biology, nanotechnology and medical drug delivery. Using a highly interdisciplinary approach, we will develop a disruptive portfolio of lipid-based foliar fertilizers that can penetrate even the most hydrophobic leaf cuticles and facilitate targeted nutrient delivery to photosynthetically active tissue in crops.  We will develop a new generation of lipid-based foliar fertilizers (LFFs) specifically targeted towards species with thick impervious cuticles. This innovative idea, inspired by the medical industry, is based on nutrient-encaged liposomes, which will act like “Trojan horses”, diffuse through any plant cuticle, regardless of its hydrophobicity, and release their aqueous cargo of nutrients inside the leaf. Thereby these particles provide a breakthrough in productivity, sustainability and climate friendliness of crop production.

Smart-P (Engineered nano- and microparticles as next-generation fertilizers for foliar application of phosphorus in agricultural plant production) Danmarks Innovationsfond Project start date: 02-10-2017 Project end date: 31-12-202121.652.000,00kr.

In this project, we will develop a new generation of foliar phosphorus (P) fertilizers based on multilayered nano- and microparticles (NMP’s), with superior leaf absorption  and low scorching tendency. These novel fertilizers will be targeted towards the early growth phase of cereals where an adequate P availability is critically important for tillering and eventually grain yields. The classical soil P fertilization is inefficient because the edaphic and climatic conditions frequently restrict sufficient mobilization of fertilizer P to the growing plants. Due to this poor P use efficiency, fields in Denmark have accumulated more than 1400 kg P/ha in the last 75 years, which should be related to the less than 30 kg P/ha removed annually by crops. This enormous P surplus represents an economic loss and a threat to the environment. SMART-P will create value by increasing the efficiency of P fertilization, boost productivity and pave the way for a more sustainable use of P in agriculture.

BioComFert (Biocompatible nanofertilizers for targeted delivery and programmed release of essential mineral ions in crops)NovoNordiskFonden |Starting date: 01-01-2022 End Date: 01-01-2028 60.000.000 kr.

Conventional strategies for soil fertilization are remarkably inefficient, as only a fraction of most  elements added with fertilizers are taken up by plants, the rest are typically trapped in the soil or leached to the aqueous environment, causing   eutrophication. Thus, one of the most important current challenges of agriculture is to improve the sustainability of food  production via an improved fertilizer efficiency. In this project, we propose a visionary approach that bypasses nutrient fixation and microbial immobilization in the soil. We will produce the first generation of foliar fertilizers based on smart nanomaterials, tailored to effectively penetrate the micro- and nanoporous leaf cuticle. We will demonstrate that nanofertilizers can be tailored to trigger cellular internalization by endocytosis and subsequently be targeted to specific tissue and organelles where they are programmed to release their cargo of plant nutrients, right at the molecular targets where they enter metabolism. Small guiding peptides will be conjugated to target a range of different nanoparticles (NPs) scaffolds either composed of plant nutrients or encaging a cargo of nutrients. We will take advantage of the very diverse chemical environments found across different organelles and utilize differences in pH, redox and hydrolytic enzyme activities to program the organelle specific dissolution of the NPs. We will use a selection of plant nutrients as experimental cases, but the technologies developed will be flexible enough to allow the loading of NPs with practically any plant nutrient. We will keep a strong focus on the ecotoxicological effects of NPs, green chemistry approaches will be applied and only biocompatible substances will introduced into the ecosystems.

International collaboration

McGill University Montreal Canada-contact person Subhasis Ghoshal (McGill University)

National collaboration

DTU Department of Energy Conversion and Storage contact person Jean-Claude Grivel

(Department of Energy Conversion and Storage — Welcome to DTU Research Database)

DTU Physics  contact person Rajmund Mokso (Department of Physics — Welcome to DTU Research Database)

Collaboration at University of Copenhagen

Section for Forest, Nature and Biomass Helle Jakobe Martens (Skov, natur og biomasse – Københavns Universitet (ku.dk))

Section for Environmental Chemistry and Physics - contact person Dominique Tobler (Sektion for Miljøkemi og Fysik – Institut for Plante- og Miljøvidenskab - Københavns Universitet (ku.dk))

Collaboration with industry

Flex Fertilizer systems- contact person Allan Holm Nielsen (FLEX Fertilizer Systems -Effektive flydende gødninger til landbruget (flex-fertilizer.com))

VeSoe APS-contact person Bjarke Veierskov

Aage Christensen A/S-contact person Søren Bidstrup (Aage Christensen – farma-, fødevare- og den kemiske industri)

SEGES Innovation contact person CAMILLA LEMMING (SEGES Innovation | Vi skaber fremtidens landbrugs- og fødevareerhverv)