Co-PIs: Ruth Grene and Oswald Crasta (Virginia Polytechnic and State University), Yinong Yang (Pennsylvania State University), Niranjan Baisakh (Louisiana State University Agricultural Center)
Collaborators: Guy Davenport and Jianbing Yan (CIMMYT, Mexico), Hei Leung (IRRI, Philippines)
Water scarcity causing drought during essential periods of plant growth can limit stable crop production. Cereal crops such as maize, wheat, rice and barley are most affected by drought during the time of flowering and initiation of grain formation, causing drastic yield losses. The goal of this project is to develop a systems biology view of drought responses in cereals to understand this complex process and improve drought resistance and water use efficiency. Genome-wide comparative transcriptome analysis of drought responses in rice and maize will be integrated into a cereal drought gene interaction network, using ortholog information to predict conserved functional relationships as a basis for cereals. Conserved orthologous regulatory genes between rice and maize involved in drought responses and resistance will be identified comprising transcription factors (TFs), protein kinases and phosphatases, genes in hormone signaling pathways, chromatin binding proteins, protein degradation and small RNA pathways. As proof of principle, a set of these putative conserved rice and maize genes will be tested by genetic analysis of mutants and natural allelic variants, assessing them for altered drought response phenotypes and perturbation in the drought gene interaction network. These analyses will validate and improve the cereal gene interaction network predictions, and provide candidate genes for improvement of drought resistance/tolerance in cereals.
With respect to broader impacts, this project will contribute through the generation of information key to the development of stable food production systems worldwide and through the creation of a transdisciplinary educational environment. Scientifically, the project will demonstrate the use of an integrated network approach to understand complex plant responses such as drought response and resistance. Outreach and training activities are integrated within the transdisciplinary plant-lab-bioinformatics project and will be made accessible to high school and underrepresented undergraduate students from institutions across Virginia and North Carolina through established programs at Virginia Tech and other nearby universities. An outreach program developed as part of a NSF-Cyberinfrastructure Training, Education, Advancement, and Mentoring for Our 21st Century Workforce (CI-TEAM) project will provide modules for quantitative data analysis for teachers and students using socio-environmental case studies from research data. An integrated mentor program for postdoctoral researchers will be used to facilitate career development. International research collaborations with the Generation Challenge Program and CGIAR institutes involved in drought research will add capacity building to agricultural systems worldwide. Plant genotypes and all data developed in the project will be made available through a project website (http://cereal-drought.vbi.vt.edu/) that will allow interactive access to data and networks. Other publicly available genetic stocks used will be distributed by the respective originators with long term public repositories. Microarray and EST data will be deposited at GEO and NCBI, respectively. All functional genomics data generated will be periodically deposited in Gramene and other public databases.
Drought or scarcity of water, affects most plants by reducing their growth or survival. Moreover, drought stress occurring during the sensitive flowering stage drastically reduces the grain yield of cereals such as rice, a crop that feeds more than half the world. In this project "Cereal drought stress response and resistance networks" we studied the effect of drought on rice and maize and identified genes and plant pathways that were altered in their expression under drought stress. To test if the genes that were induced in expression by drought were important or needed by the plant, we analyzed loss-of-function mutants of these genes in rice and found many that were necessary for plant growth and grain yield under drought. We studied these genes in naturally occurring varieties of rice and found different forms of the gene, including with higher expression, which could therefore be used for developing new varieties that could yield more under drought stress as well as normal conditions. These regulatory genes form part of a regulatory network that are necessary for the maintenance of important biological processes such as photosynthesis, and for grain yield of rice under drought as well as normal well-watered conditions. The major contributions of the project are development of network models that explain and predict some of the genes and processes involved in protection of plants to drought stress, as well as important for high grain yield of rice and potentially other cereals. The broader impacts of this project include a High School outreach program named "Our Green Future", held over 2 years, where high school students spent a week with scientists at Virginia Tech learning various subjects such as variation caused by plant gene mutants and nature, isolation of plant DNA from fruit, and computer simulations of disease outbreaks. We also demonstrated the importance of drought research at the USA Science & Engineering Festival at Washington DC (2010), reaching more than 2000 school students and participated in Kids Tech University with interactive displays on the effect of environmental stress on plants and natural genetic variation, attracting students of all age groups. The results of this project will be of value for development of drought resistant varieties of rice and other cereals that also produce higher grain yield.
