Heike Inge Sederoff
Bio
Metabolic Engineering to Improve Sustainability of Agriculture
Agricultural crop production is facing many challenges – now and in the future. An anticipated increase in the demand for food and feed under changing climate conditions requires improvements to quality and quantity of production. Our research aims to understand the molecular mechanisms responsible for plant responses to nutrient limitations of nitrogen, phosphate and water. To improve sustainability of agricultural crop production, we have engineered new pathways into plants that improve their efficiency in photosynthetic CO2 fixation, reduce energy and carbon losses, and increase their nutrient use efficiency.
Metabolic Engineering to Increase Oil Seed Crop Yield
Camelina sativa is an excellent oil crop for feed and biofuel production because it grows with little water and fertilizer on marginal land. To improve camelina as a dedicated biofuel plant, we have increased its photosynthetic CO2-fixation rates by modifying CO2 transport, assimilation and allocation and reducing the cost of photorespiraton. To extend its agricultural range, we are improving its stress tolerance against heat and drought.
Technology Development
We are currently working on new technologies to modify the plastid genome and regenerate homoplasmic crops. This technology will enable the generation of crops with better pest-resistance and provide a platform for the fast and safe production of biopharmaceuticals.
Re-engineering Arbuscular Mycorrhizal Symbiosis Brassicaeceae
Plants have evolved to optimize growth and survival in their physical (abiotic) and biological (biotic) environment. An important interaction is the ability to build symbiotic relationships with fungi and bacteria that enable them to access essential nutrients like nitrogen, phosphate and water beyond the reach or ability of their roots. A symbiotic relationship has evolved between plant roots and specific fungi (e.g. Rhizophagus irregularis) which invade and form Arbuscular Mycorrhizae (AM). These fungal hyphae are thinner than plant roots and can therefore access nutrients and especially immobile phosphate in the soil in spaces the plant root cannot reach. AM fungi establishes an intracellular membrane system within host cells that enables the exchange of sugar and lipids from the plant for nutrients and water from the fungus. The great majority (~95%) of plant species on Earth form AM whereas, the agriculturally important Brassicaceae (e.g. rapeseed, mustards, cauliflower, cabbage) and Amaranthaceae (e.g. spinach, beets, quinoa) have lost the ability to establish this type of symbiosis with fungi. We have carried out comparative genome analysis of known symbiosis pathway elements and are transforming the “lost genes” into Camelina in an attempt to re-establish their ability to host AM.
Bigger and Better Sweet Potatoes
Sweet potato is ranked by the Food and Agricultural Organization (FAO) as the seventh most important food crop in the world (FAO, 2013). In Ghana, sweet potato has been ranked as the fourth most important crop. The crop is a rich source of important nutrients including beta carotene, and this makes sweet potato an important crop to alleviate malnutrition and vitamin A deficiency in the developing countries. North Carolina is the No.1 sweet potato producing US State and NCSU has the largest breeding project in the US. We are developing gene-editing technologies for sweet potato to further increase its yield and nutritional content.
Courses taught:
- BIT 476/576 Applied Bioinformatics
- PB 751 Advanced Plant Physiology (Spring)
- PB 495/595 Innovation in Agricultural Biotechnology (Fall)
Education
Ph.D. Biochemistry University of Goettingen, Germany 1993
M.S. Biochemistry University of Goettingen, Germany 1990
Area(s) of Expertise
Plant Physiology and Metabolic Engineering
Publications
- IPD3, a master regulator of arbuscular mycorrhizal symbiosis, affects genes for immunity and metabolism of non-host Arabidopsis when restored long after its evolutionary loss , PLANT MOLECULAR BIOLOGY (2024)
- Long- and short-read sequencing methods discover distinct circular RNA pools in Lotus japonicus , PLANT GENOME (2024)
- Back to the Future: Re-Engineering the Evolutionarily Lost Arbuscular Mycorrhiza Host Trait to Improve Climate Resilience for Agriculture , CRITICAL REVIEWS IN PLANT SCIENCES (2023)
- Emergent molecular traits of lettuce and tomato grown under wavelength-selective solar cells , FRONTIERS IN PLANT SCIENCE (2023)
- Exceptionally high genetic variance of the doubled haploid (DH) population of poplar , JOURNAL OF FORESTRY RESEARCH (2023)
- Re-engineering a lost trait:IPD3, a master regulator of arbuscular mycorrhizal symbiosis, affects genes for immunity and metabolism of non-host Arabidopsis when restored long after its evolutionary loss , (2023)
- Gene sdaB Is Involved in the Nematocidal Activity of Enterobacter ludwigii AA4 Against the Pine Wood Nematode Bursaphelenchus xylophilus , FRONTIERS IN MICROBIOLOGY (2022)
- High-throughput detection of T-DNA insertion sites for multiple transgenes in complex genomes , BMC GENOMICS (2022)
- Organic solar powered greenhouse performance optimization and global economic opportunity , ENERGY & ENVIRONMENTAL SCIENCE (2022)
- The double flower variant of yellowhorn is due to a LINE1 transposon-mediated insertion , PLANT PHYSIOLOGY (2022)
Grants
One of the grand challenges facing humanity is to secure sufficient and healthy food for the increasing world population. This requires maintaining sustainable cultivation of crop plants under changing climate conditions. Plant roots and soil microbes have been associated since the emergence of plants on land. Nevertheless, the mechanisms that coevolved to control and regulate microbiota associations with healthy plants are largely unexplored. The photosynthetically active green leaf tissues supply assimilated carbon to roots for development and also to feed its associated microbes. To maintain balanced growth, plants have to integrate this underground demand and regulate the rate of photosynthetic CO2 fixation, and sugar allocation needs to be coordinated between root and shoot. Research on plants and their naturally associated microorganisms is therefore in a prime position to provide new perspectives and concepts for understanding plant function, plant performance and plant growth under limited input conditions with a reduced environmental footprint and could also define breeding targets and develop microbial interventions. InRoot aims to: 1. Disentangle the effects of climate and soil type from the impact of root-microbe interactions through transplantation experiments and exploit natural variation to identify the plant genetic components responsible for adaptation to the local microbiota. 2. Identify key bacterial taxa governing the establishment of host-driven microbial networks in the rhizosphere by analysing the microbe-microbe and microbe-host interactions established in tailored synthetic communities (SynComs) with direct consequences on host performance. 3. Define the plant genetic components that control infection of plant roots by ubiquitous and host-specific endophytes using advanced genetic screens and new methods for quantifying root cellular responses to microbes 4. Understand molecular mechanisms integrating root-microbe interactions into whole-plant physiology by investigating systemic physiological responses induced by SynComs using whole plant phenotyping. 5. Predict plant performance as a function of plant and microbiota genotypes by building multiscale models based on genotype, phenotype, and mechanistic data thereby providing knowledge for application. InRoot perspective: Provide knowledge and tools for science-based development of new crop varieties and associated microbial interventions that will improve productivity, reduce the need for fertilizers and pesticides, and alleviate negative environmental impact.
Challenges at the FEW nexus are not simply technological, but convergent in the sense of spanning technical, ecological, social, political, and ethical issues. The field of biotechnology is evolving rapidly - and with it, the potential for creating a diverse array of powerful future products that could intentionally and unintentionally impact FEW systems. Depending on what products are developed and how those products are deployed, biotechnology could have a positive or negative impact on all 3 of these systems. Wise decisions will require leaders who can integrate knowledge from engineering, design, natural sciences, and social sciences. We will train STEM graduate students to respond to these challenges by conducting convergent research aimed at development, and assessment of biotechnologies to improve services provided by FEW systems. We will train our students to engage with non-scientists to elevate societal discourse about biotechnology. We will recruit 3 cohorts with emphasis on students who have shown a passion for crossing between natural and social sciences. We will work with the NCSU Initiative for Maximizing Student Diversity in recruiting students from underrepresented minority groups. Cohorts will have 6 students who will take a minor in Genetic Engineering and Society (GES). They will receive PhDs in established graduate programs such as Plant Biol, Chem & Biomol Engr, Econ, Public Adm, Entomol, Plant Path, Communication, Rhetoric & Digital Media, Forestry & Environ Res, Crop & Soil Sci, and Genetics. For students in natural science PhD programs, at least 1 thesis committee member will be from a social sciences program and vice versa for students in social sciences. For all students, at least 1 thesis chapter will demonstrate scholarship across natural and social sciences. The disciplinary breadth of our proposed NRT is very broad, so we will focus student projects narrowly on a specific biotechnology product that impact FEW systems. When they first arrive at NCSU, cohorts will participate in a training program off campus where they will be exposed to the issues they will address. Students will carry out a group project in the focus area of the cohort to continue team development. To fulfill the GES minor, students will take 3 specially designed courses: Plant Genetics & Physiology, Science Communication & Engagement, Policy & Systems Modeling. There are no NRT-eligible institutions partnering on this project outside of an evaluation role.
The NCSU Phytotron is a premier growth facility that serves the NCSU community, as well as other NC academic institutions and NC companies of various sizes. The Phytotron has always maintained a high-level of precision in regulating environmental conditions. The facility is now more than 50 years old and after many years of heavy use, it has required major renovations and upgrades to keep up with research needs. We were able to conduct an extensive energy conservation project with the NCSU Facilities group to upgrade the growth chambers, as well as the heating, cooling and electrical systems of the Phytotron. During the renovation process we lost precision in controlling the environmental variables of the Phytotron greenhouses. Facilities with a high level of precision in environmental control are necessary for securing research funds, conducting repeatable experiments and enhance graduate student performance. We seek to install a state-of-the-art control system that can be used to not only allow us to precisely control the environmental conditions of the greenhouses but would also increase our capabilities including use of the specialized moisture sensing and weighing system that was donated by Syngenta to the NCSU Horticultural Science Department and requires an Argus system to function. The Argus system that we are requesting would provide state-of-the-art environmental control that is not currently available in any of other plant growth areas at NCSU and would provide the Phytotron with a system similar to the ones used at state-of-the-art growth facilities in RTP. It would also allow connectivity between the Phytotron and the new Plant Sciences building that is being constructed on NCSU??????????????????s Centennial Campus.
The objective of this research is to develop semi-transparent organic solar modules integrated with greenhouses along with engineered plant photo-action spectra that synergistically provide food and energy sources while conserving water for a new food-energy-water paradigm.
The United States Agency for International Development (USAID), in partnership with the Association of Public and Land-grant Universities (APLU) and the International Maize and Wheat Improvement Center (CIMMYT) in Mexico, selected Michigan State University (MSU) to implement the Feed the Future Borlaug Higher Education for Agricultural Research and Development (BHEARD) Program. The goal of this project is to increase the number of agricultural scientists working in the developing world and to strengthen scientific institutions in developing countries. To do this, the BHEARD program plans support long-term training of agricultural researchers at the master??????????????????s and doctoral levels through linkages in the scientific and higher education communities in Feed the Future countries and the United States. During Fall 2015 a BHEARD Expression of Interest was sent to APLU members to solicit mentors for students selected for this program. Drs. Yencho and Sederoff were selected as a good match for Mr. Samuel Acheampong, who is interested in working in sweetpotato biotechnology. Yencho and Sederoff are working with Jose Cisneros, Director of CALS International Programs to implement this training.
NC State's EFRI PSBR program will model, develop, implement, and evaluate a scalable photosynthetic biorefinery (PSBR) that uses transformational nutrient recycle processes and supports efficient conversion of CO2 to lipid (oil) in a marine microalgae-based system. Algal oils are an ideal feedstock for biofuels production, offering high production density and the ability to use marginal water (municipal wastewater, brackish water, etc.) and reuse CO2 in flue gases. However, there are a number of technical challenges associated with culturing algae in current generation PSBRs. Using a tightly coupled synergistic approach employing both Engineers and Biologists, the team will: a) genetically engineer a marine microalgae species (Dunaliella spp.) with enhanced CO2 uptake/fixation and the capability to recycle N and P from microalgal biomass; b) design a small-scale PSBR informed by our kinetic model which will be used to develop a scalable dynamic reactor model based on computational fluids dynamic simulation of the PSBR; c) develop innovative, scalable approaches for algal harvesting and lipid extraction; and d) develop an analytical framework for the LCA of our microalgal PSBR system to include creation of flexible and scalable cost and LCI process models that will ultimately lead to generation of a robust PSBR life-cycle decision tool that can be applied to this and other PSBR systems. Intellectual Merit New technologies developed as a result of this project for scalable, sustainable culturing of phototrophic marine microalgae for optimized algal oil production will broaden scientific discovery and create the framework, synergy and momentum for biologists and engineers to further explore rational design and operation of PSBRs. Genetic enhancement, reactor modeling, and LCA will be used to optimize production of algal biomass and lipids in our PSBR. Exploration of innovative and efficient means for algal CO2 uptake/fixation, cell harvesting, lipid extraction, and nutrient and water recycle, will transform the scientific development of algae-based biorefineries. Demonstration of novel Lagrangian microsensors that can assess accumulation of light radiation in proportion to its exposure during transport through the reactor will significantly aid in the modeling and testing of PSBR operation in response to light. PSBR design optimization enabled by our experiment-informed kinetic and CFD modeling and LCA will advance knowledge in rational microalgal-based PSBR design and operation, ultimately leading to development of fully scalable and sustainable biofuel feedstock production systems. Broader Impacts The development of truly scalable and sustainable PSBRs offers tremendous economic and environmental impact by reducing the transportation sector?s reliance on fossil fuels. This increases the prospect of finally being able to fully exploit the promise of algae as a biofuels feedstock, given that production of algal-oil derived biofuels that are fully compatible with all existing infrastructure has been demonstrated. Innovative and transformative enabling-technologies that will permit robust production of marine microalgae biomass and lipids in scalable and sustainable PSBRs will bring significant environmental and economic benefits to the nation through the development of an efficient, high-yield alternative energy feedstock production platform. This interdisciplinary research among engineers, microbiologists, molecular biologists and plant physiologists provides unique training opportunities for high school, undergraduate, graduate and postdoctoral scholars to bridge traditional disciplines and become the new generation of scientists and engineers to develop renewable energy for future generations.
Marine microalgae are fast-growing single cell plants and ideal for biofuel production because they do not compete with land or fresh water required for food and feed production. Their ability to grow in saltwater also prevents contamination that often leads to culture crash in other production systems. Currently microalgae platforms for biofuel production are not commercially viable. Companies using algae systems for fuel production have added high value co-products used in the chemical industry for profitability. Our technology will enable algae-based biofuel production to be commercially viable by producing industrial enzymes at very little extra cost but high-volume and profit potential. Currently most industrial enzymes are produced in bacteria or yeast cells which allows high density, but require feeding of expensive substrates (sugars, protein sources, vitamins). Other benefits include the high volume of algae production and the easy extraction and purification because the marine microalgae of choice - Dunaliella viridis - has no cell wall and extraction only requires mild osmotic shock (fresh water). Essentially these enzymes would be recovered from the ??A???a?sA???a??waste stream??A???a?sA???A? of algae biofuel production. Although enzymes and proteins for the pharmaceutical industry have higher value, they also require FDA approval and would not be suitable for growth in fuel producing algae systems. Organisms living in extreme environments (Extremophiles) produce enzymes (extremozymes) that can function under extreme physical and chemical conditions. These extremozymes have higher value for industrial and military use because of their physical features, their higher substrate specificity and their better stability. Our technology will generate marine algae strains as feedstock for biofuels that produce extremozymes as a co-product.
The new equipment will serve a diverse user community. Because of its combined capability as a highthroughputb sequencer that generates reads ultra fast, it will be an essential tool in research requiring: 1) variant detection for genotyping breeding populations, 2) near real-time metagenomics remediation assays and other population surveys, 3) SNP detection, genotyping, and genetic mapping, 4) transcriptome sequencing and gene expression analysis, and 5) full genome and targeted resequencing (including ChIP seq and bisulfite-treated DNA applications)
Plants provide a complete and economical means for human life support for long-term space exploration and habitation. However, since the space environment is not optimal for plant growth, an understanding of how plants sense and respond to changes in their environment is of fundamental importance. The phosphoinositide (PI) pathway is highly conserved among eukaryotes and functions in the regulation of a multitude of cellular pathways. The lipid-derived second messenger inositol 1,4,5-trisphosphate (InsP3) increases in response to many different stresses. We have shown that InsP3 levels increase with gravistimulation prior to visible bending in both monocot and dicot systems. We have generated transgenic Arabidopsis plants expressing the mammalian type I inositol polyphosphate 5-phosphatase (InsP 5-ptase), an enzyme that specifically hydrolyzes InsP3 and terminates the signal. The transgenic plants have normal growth and morphology; however, they exhibit altered responses to many environmental stimuli including gravity, drought and cold. While rapid changes in transcript levels occur in wild type Arabidopsis within 5 min of gravistimulation, the expression of several of the fastest responding genes does not change in the InsP 5-ptase roots in response to reorientation. Our hypothesis is that InsP3 is an important second messenger in the sensing and signaling of stimuli (including gravity). The plants with compromised InsP3 signaling therefore, provide a valuable tool for dissecting the role of the InsP3 pathway in plant responses to the microgravity environment encountered on the International Space Station. Our primary aim is to identify the molecular changes that are specifically mediated by InsP3 in the space environment. We will compare transcript and protein profiles of wild type and transgenic plants that are grown in both microgravity and 1g in space as well as on the ground. The long term goal is to understand the molecular mechanisms plants use to sense and respond to changes in their environment. This knowledge will help design plants which are better able to withstand space flight and microgravity conditions.
Plant Systems Biology resides at the intersection of biology and engineering, where practitioners integrate multi-scale systems engineering approaches with biological data. Systems biology is used to model, understand, and control combinatorial biological interactions across physiological, structural, and biomolecular processes. Directed focus of systems biology on plants will facilitate the exploration of the governing mechanisms behind complex biological processes, culminating in the design of whole plant systems; specifically the control of factors that impact plant metabolism, development, and adaptation. Successful Plant Systems Biology research and educational programs will also be at the forefront of the transformation of plant biology in the post-genomic era. While there exists reasonable efforts in plant systems biology that has been established in both the United States and in Europe, consolidated efforts in this field for modeling and controlling whole plant systems remains elusive. With all parties having similar long term goals, it would benefit all parties if efforts were taken to standardize approaches, format data repositories, and clarify policies around coordinated approaches for addressing common objectives. We request funds to support a Plant Systems Biology workshop that will provide a venue for 30 national and international researchers with interests in plant systems biology to discuss and highlight limitations and focus on critical questions associated with feasibility and necessary technological and experimental advances for large-scale design of plant systems. The specific workshop objectives are as follows: 1) Explore and identify areas of complementary interests, needs, and opportunities associated with the growing discipline of Plant Systems Biology. 2) Identify the primary research grand challenges and explore potential limits of the field from both the biological, computational, and engineering perspectives. 3) Formulate funding strategies for future collaborations.