Plant Resilience for Food Security and Human Health in Changing Climates
Food insecurity is one of the greatest risks to human health. Threats to agriculture like hurricanes, tornadoes, droughts, and devasting outbreaks of disease are becoming more frequent, more powerful, more damaging, and less predictable. Climate- and disease-proofing crops and protecting wild ecosystems thus requires resilient plants that will thrive in a changing world, while using agricultural practices that mitigate rather than exacerbate extreme weather and disease events. This will also protect natural lands, which provide important ecosystem services and buffer extreme weather events.
To address these challenges, we recently founded the Plant Adaptability and Resilience Center (PlantARC), comprised of seven plant biology research groups that address overlapping questions with unique approaches, plus local and global partners. PlantARC leverages fundamental research to enhance plant adaptability and resilience. We tackle three major challenges. First, warming temperatures, shifting seasons, and unpredictable precipitation alter plant germination, growth, flowering, and seed development in complex and interconnected ways. Resolving the threat to global agriculture will require a deep understanding of how climate change alters plant physiology, growth, and development. Second, weneed to develop plants that are adaptable and resilient in the face of frequent abiotic stresses. Third, climate change is disrupting entire ecosystems, including the microbes and pollinators that plants rely on to grow and reproduce. Long-lasting resilience to climate change requires strategies to safeguard these crucial species interactions from the worst effects of a changing climate. We need research-driven scalable solutions that can be implemented close to home—in urban settings—and across the globe.
The problem
Our overarching research goal is to identify, characterize, and utilize internal plant pathways and natural variation in a suite of economically and ecologically important plants to understand and, in the process, engineer and select plants with increased levels of resiliency across the spectrum of important biological processes. Key for successful completion of these goals are investments in sophisticated, controlled environment, growth chambers that allow us to (1) simulate past, current, and future climates from anywhere in the world, (2) reproduce a given climate precisely in replicate experiments and (3) test plant response to successive, but different, climate exposures.
Two broad examples for sustainable improvement of plant traits for agriculture: we ensure that crops optimally allocate the resources they generate to the plant organs we eat, and we enhance the ability of crops to maintain productivity through non-average events, such as heat waves and droughts. Both of these should enhance yield directly, allowing for denser planting and relaxing pressures on natural lands and fossil-fuel requirements. A list of the key processes of interest is below, with a brief description of the importance of increasing resilience in plant species and across systems in the face of a changing global structure (e.g. increased urbanization) and climate (e.g. global climate change).
A. Plant Physiology, Growth and Development in the Context of Climate Change
Plants develop their final form not in the embryo found in the seed but after germination, in accordance with the prevailing environmental conditions. Plant development is marked by a series of dynamic shifts, one of which is the transition from the juvenile to adult phase and the conversion of growth to flowering are two of the most important. Both are exquisitely sensitive to environmental cues, and therefore climate change. A major concern is that in changing climates, these developmental transitions become maladapted, leading to reduced growth and yield in agriculture. Building on our current research strengths we are identifying and dissecting plant pathways that can be tuned for optimal plant development and food security in changing climates.
B. Plant Adaptability and Resilience Strategies in Response to Fluctuating Climate (Abiotic Stress)
Plants have diverse adaptability and resilience strategies in the face of stress, differing with plant age, nutrient status, and the type of environmental challenge (single versus multiple stresses, stress duration, stress frequency). Stress response is usually rapid and reversible and often takes resources away from, and thus negatively impacts, growth and yield. We will harness our understanding of hormonal, epi-transcriptomic and epigenetic plant stress responses that dynamically alter protein, RNA, and genome activity in different climates to reveal, understand, and modify regulatory interactions that will result in broadly stress resilient plants without growth penalty.
C. Multispecies Interactions in Response to Fluctuating Climate
Plants in nature do not grow unassisted. Both roots and foliage form fungal and microbial interactions that increase nutrient uptake, especially phosphorous and nitrogen, and reduce water loss. Plants also form communities with other plants and support insects that can either be beneficial or predatory in nature. In ecosystems and agriculture alike, increasing emphasis is placed on the resilience of systems, not just individual species. We will conduct field and controlled environment experiments on multispecies communities to define systems that reduce phosphorus and nitrogen fertilizer dependency and increase plant resilience. Critical is improving soil health and practices such a polyculture that mitigate crop loss by distributing effects of adverse environmental conditions over multiple crop species, each adapted to different environments.
Approaches
PlantARC uses natural diversity in plant populations or communities, diversity driven by domestication in crops compared to their wild relatives, or present in mutants and genetic variants resulting from genetic and reverse genetic approaches in model plant species to identify the genetic basis of key adaptability and resilience traits.
Cellular level insight into these dynamics will be furthered by applying state-of-the-art techniques such as single nuclei RNA-seq and spatial transcriptomics. Integration of the phenotypic macro (whole plant, plant community) and micro ((sub)cellular) responses will rely on cutting edge data science (AI, machine learning, bioinformatics) enabling in depth exploration of the complex cellular responses and their interactions with environmental stimuli. Such findings will uncover the pathways, and central nodes therein, to be targeted by precision-guided strategies for plant improvement.
The latter relies in addition on developing rapid transgene-free new breeding technology approaches, including those based on CRISPR or epigenome engineering. We will identify the best genetic targets in our three focus areas to select or engineer crop plants and plant communities with enhanced resilience to environmental changes and improve basic architecture to enhance survival and output in both the large-scale and the urban setting. The plant species derived from these new breeding technologies will provide solutions for reduced greenhouse gas emission, enhanced food security and plant/plant community survival in the face of global climate change.
Implementation
PlantARC engages both with the local and the global community to sustainably enhance food security given environmental challenges, population growth and urbanization. In Philadelphia, PlantARC collaborates with support systems and local stakeholders in urban gardens and farms to tackle obstacles such as growth of ancestral foods in a different climate, land use, soil contamination, water availability and training. For global agriculture, plantARC investigators harness natural diversity to identify leaf tissue adaptations in sorghum cultivars that promote tolerance to drought and heat, and reduced defense tradeoffs in nitrogen fixing cover crops. They also achieved drought resilience without tradeoffs in vigor or growth, currently being tested in rice. PlantARC partners with different schools and programs on campus and beyond and at other universities and institutes.
