Our Research Program
The overarching research goal of Penn Plant ARC will be 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 phytotrons 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. The capabilities of our planned phytotrons are unprecedented nationally and internationally.
Our goal is precision improvement of plant traits for agriculture and ecosystems generally and specifically in the urban setting. We will focus on three plant families, the Brassicaceae, which include the model species Arabidopsis, as well as leafy vegetables (kale, collards, and cabbages) and cover crops; the Fabaceae (beans, peas and alfalfa) that enter into symbioses with nitrogen-fixing bacteria, are key cover crops, sustainable alternatives to chemical fertilizer, and models for multispecies interactions; and the Poaceae, that include the top world-wide crops maize, rice, wheat, and sorghum, as well as other grasses important for grazing and/or making up natural grasslands such as prairies.
The following are key processes of interest:
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, of which the transition from 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 poor survival in natural habitats, and reduced growth and yield in agriculture. Building on our current research strengths and phytotron climate tests, we will identify, dissect and modulate plant pathways 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 (in phytotrons) 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 (phytotron) based experiments on multispecies communities to define systems that reduce phosphorus and nitrogen fertilizer dependency and increase plant resilience.