Grafting is used in many crop plants to boost productivity, confer tolerance to sub-optimal environments and diseases, and facilitate efficient harvesting through modified shoot structure. Despite its widespread use, a basic understanding of the mechanisms that underlie successful graft combinations is lacking, making it impossible to precisely predict beneficial graft combinations. Research conducted on this project will help elucidate the mechanisms that underlie communication between grafted root and shoot systems. Progress in this area has the potential to transform the practice of grafting into a more precise science, enabling scientists and farmers to rapidly adapt crops to combat new diseases, handle environmental fluctuations, and restructure growth habits for improved crop productivity. In addition to providing research training for undergraduate students, graduate students, and a postdoctoral researcher, the project will emphasize science communication, and students will help design and host public workshops on plant grafting. Related undergraduate training will be offered through the implementation of a novel visual and experiential learning pedagogy, based on 3-dimensional X-ray imaging and other hands-on image capture activities, for Cornell’s introductory undergraduate botany course.
Long-distance signaling is known to play a fundamental role in the growth and stress response mechanisms in plants, as well as related processes including grafting, and thus is critical from an agricultural point of view. Unfortunately, the processes underlying these signaling pathways remain poorly understood, even at the most basic level. A prime example involves the role of mRNAs in long-distance signaling, which until recently were assumed to function almost exclusively within the cells where they are produced. However, new studies that rely on polymorphism-based detection of mobile transcripts between heterografted root and shoot systems demonstrate that a large number of distinct RNA species move across distant organ systems. The potential significance of this plant “mobileome†is a heavily debated topic, with widespread disagreement over whether mobile RNAs represent a collection of long-distance signals or are simply noise in the vascular system. Much of this controversy is due to the lack of fundamental knowledge about how the plant mobileome works. The research objectives of this proposal are: 1) to resolve the fundamental question of whether mRNAs play a crucial role in long-distance signaling and grafting; 2) to more generally explore the mobility of mRNA in plants; and 3) to further our understanding of the mechanisms of transport as a means to realize the long-term goal of engineering and deploying artificial mRNAs to confer agriculturally desirable traits. These goals will be achieved through the production of novel genomic resources, and the use of temporal sampling, computational genomics, and high-resolution, in vivo RNA imaging, which will ultimately provide insight into the dynamic behavior of long-distance RNA movement.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
