Research interests…...

 

Description Of Research

 

We are always looking for highly motivated and dedicated researchers interested in plant biology. If you would like to join our group send your CV and a statement of your research interests and accomplishments to Reddy (reddy@colostate.edu).

 

One of the fundamental questions in plant biology is how plants sense and respond to environmental (abiotic and biotic) and hormonal signals that regulate diverse cellular processes and various aspects of plant growth and development.  Our group has been studying i) calcium-mediated signal transduction mechanisms with emphasis on calcium sensors and their target proteins, ii) mechanisms that regulate basic and alternative splicing of pre-messenger RNAs in response to stresses, iii) disease resistance, iv) cell wall degrading enzymes for biofuel production and iv) synthetic signal transduction circuits in plants.  We use molecular, cell biological, genetic, biochemical, bioinformatics and computational tools to accomplish our research goals.  Arabidopsis, maize, potato and Miscanthus are used in our research.  Studies on computational aspects of alternative splicing and protein-protein interactions are being done in collaboration with Asa Ben-Hur in the Department of Computer Science at CSU  (http://www.cs.colostate.edu/~asa/projects.html).

In signaling research, our work is focused on calcium/calmodulin-mediated signal transduction mechanisms in plant growth and development, and in plant responses to pathogens and abiotic stresses.  Calcium is a key messenger in transducing diverse signals in plants.   We have been particularly interested in calcium sensors and downstream targets of calcium sensors in understanding diverse cellular and physiological processes regulated by calcium.  Using bioinformatics tools we have extensively characterized several gene families involved in calcium signaling.  In a comprehensive screen for calmodulin interacting proteins, we identified over 100 calmodulin-binding proteins ranging from transcription factors to molecular motors.  During the last twenty years we have been studying the function of several of these calmodulin-binding proteins in plant growth and development, and plant responses to various biotic and abiotic stresses.   Our group has extensively characterized function and regulation a novel calcium/calmodulin-regulated microtubule motor protein involved in cell morphogenesis and cell division.  We have identified several calmodulin target proteins that play a central role in plant disease resistance and abiotic stress responses and elucidated signaling pathways involving these proteins.  Additionally, we demonstrated a critical role for a pollen-specific calmodulin-binding protein in pollen germination.  We have generated and tested chimeric motors and receptors by combining modular domains from plant and animal proteins for potential applications in synthetic biology and nanobiotechnolgy.

In gene regulation area, our focus is on precursor-mRNA splicing.  Alternative splicing of pre-mRNAs is emerging as an important step in regulating transcriptome complexity and eventually proteome diversity.  More recently, it has become evident that alternative splicing is coupled to nonsense-mediated decay to regulate the abundance of transcripts through a mechanism called regulated unproductive splicing and translation (RUST).  Our group has been studying spliceosomal proteins, identified several putative splicing regulators, called serine/arginine-rich (SR) proteins, and analyzed their functions using a variety of genetic, biochemical and cell biological approaches.  By studying alternative splicing of Arabidopsis SR genes, we have demonstrated extensive alternative splicing (generation of over 90 splice variants from 15 genes) of this family of genes.  Furthermore, out studies have demonstrated that stresses have rapid and dramatic effect on alternative splicing, suggesting rapid reprogramming of gene expression at the splicing level.  Recent studies suggest that plants can rapidly alter their transcriptome complexity in response to stresses by regulating alternative splicing of master splicing regulators.

Our current focus is on genome-scale analyses of targets of calmodulin-regulated transcription factors and stress-regulated alternative splicing in various mutants, using high-throughput next generation sequencing technologies (ChIP-seq, RNA-seq and RIP-seq) and computational tools. A thorough understanding of mechanisms by which plants respond to stresses will pave the way to engineer plants that are capable of growing well under adverse environmental conditions.  In addition to these projects, we are also working on developing transformation tools in Miscanthus, a potential energy crop, and cloning and expression of cell wall degrading enzymes from fungal species with an ultimate goal to use them in the production of ethanol from lignocellulose.