Current Projects
Mapping the Root Xylem Cell Specification and Differentiation Regulatory Network
(Hellman Fellowship and startup funds)
Mallorie Taylor-Teeples
Characterizing Polycomb Repressive Complex 2 Function at Cell Type Resolution
(EMBO Postdoctoral Fellowship and HFSP Fellowship)
Miguel de Lucas
Identification of Loci Regulating Root Architecture in Tomato
(National Science Foundation grant #NSF IOS:1052395)
Mily Ron and
Ted Toal
The root is of vital importance because it anchors plants to the soil and it absorbs and transports water, nutrients and solutes to the shoot. Despite its importance, questions remain about how root architecture is controlled, particularly in important crops. Which genes and pathways regulate root architecture, cell patterning and proliferation? How are these genes and pathways different in plants that display natural variation in root architecture? Which root architecture genes were selected during domestication of crops from wild species?
Root architecture in the wild tomato relative, Solanum pennellii, is of special interest, due to its drought and salinity tolerance. This project will identify important genes regulating root development using lines derived from a cross between wild S. pennellii and domesticated tomato (S. lycopersicum). Each line has different genes from S. pennellii that may contribute to its root architecture. Morphological and cellular measures of root development, along with molecular genomic data describing gene expression differences will be collected for this population. Using these data and statistical and computational methods quantitative trait loci (QTL) and expression QTL (eQTL) that contribute to differences in root architecture will be identified. Further work will define gene regulatory interactions, biological processes, and ancestral regulatory pathways as well as identify candidate causal genes controlling variation in root development.
A significant goal of this project is to train all team members in an interdisciplinary manner linking quantitative biology to the cell biology associated with plant development. For many, tomato is a major component of the daily meal and it constitutes an important source of minerals, vitamins, and antioxidants. This project will identify genes influencing root architecture, and potentially drought resistance and insect tolerance in this important crop. The outcome will influence our basic understanding of genes and regulatory pathways associated with root development, speciation and evolution.
Integrative Analysis of Plasticity in Cell Fate Determination in Plants
(National Science Foundation grant #NSF IOS:1238243,
Finnish Cultural Foundation and NSF Graduate Research Fellowship)
Kaisa Kajala and
Gina Turco
From the germination of a seed to the fertilization events that lead to the next generation, plant development is exquisitely orchestrated by genetically determined processes that are fine-tuned by environmental cues. This entails the precise regulation of networks of genes in individual cells over the course of the plant life cycle. This project will decipher the complex regulation of genes within specific types of cells of the plant. This will be accomplished by transfer of methods pioneered by this team in the model plant species Arabidopsis thaliana to three important crops: rice, alfalfa, and tomato. These technologies allow for the isolation of cell nuclei containing DNA and RNA and the ribosomes that translate mRNA into protein from targeted subpopulations of cells of a leaf, root or other organs, without the need for dissection. The new genetic resources developed will be used to study how development is perturbed by two major environmental threats to US agriculture: drought and flood. The outcome will be a greater understanding of the integration of plant development with environmental cues.
The project will have multiple broader impacts. Using parallel multi-tiered and computationally robust analyses, the project will address two important biological questions: How does gene regulation in the stem cells (meristem) of roots and shoots differ across species? How does environmental stress influence the development of specialized cell types in the root? The findings will provide insights that could facilitate downstream improvement of abiotic stress tolerance. It will also generate resources for the evaluation of cell-type specific expression in three important crops. The seed material and data sets will be shared with the plant genome research community through the NCBI Short Read Archive (SRA, http://www.ncbi.nlm.nih.gov/sra) and Gramene (http://www.gramene.org/). Finally, the project will engage postdoctoral researchers and graduate students in advanced interdisciplinary training in biology and computational sciences, who will benefit from the experience of mentoring undergraduate students in research. Finally, the project will engage high school students in the classroom and the laboratory, develop teaching tools, and foster greater understanding of the importance of plant research to humankind.