Characterizing the roles of Arabidopsis calmodulin-like protein, CML39, in hormonal regulation of early seedling development and fruit formation.
Calcium (Ca2+) is considered among the most ubiquitous and versatile second messengers in eukaryotes. Cytosolic Ca2+-oscillations are evoked by environmental stimuli such as biotic or abiotic stresses and developmental cues. In turn, these Ca2+signals are detected by Ca2+-binding proteins, termed Ca2+ sensors, that help coordinate physiological responses by binding to and regulating the activities of various proteins. Calmodulin (CaM) is an evolutionarily-conserved eukaryotic Ca2+ sensor involved in many signal transduction pathways. Interestingly, plants possess large families of unique Ca2+sensors related to CaM and known as calmodulin-like (CML) proteins. Several CMLs have been implicated in developmental and stress-response signalling but the roles of most CMLs remain unknown. We recently reported the importance of Arabidopsis CML39 in early seedling establishment (Bender et al 2013, Plant J: 76:634). CML39 knock-out (KO) mutants display developmental arrest in the absence of exogenous sucrose. Our ongoing phenotypic analysis of cml39 knock-out plants has identified several additional developmental abnormalities in these mutants. In comparison to wild-type plants, cml39 mutants display perturbations in response to exogenous hormones, altered fruit morphologies, and unusual germination properties. Qualitative and quantitative studies describing the phenotypic characteristics of cml39vs wild-type plants are presented. In addition, a putative interacting partner (CML39IP) of CML39 was identified through yeast-two-hybrid screens. Here, we present preliminary data for the delineation of the interaction domain along with the phenotypic analysis of KO mutants of CML39IP.
Follow the chemistry: Making and breaking odd bonds with enzymes.
Microbes are an incredible source of diverse enzyme chemistries. This reflects an unrelenting evolutionary pressure to develop catabolic and biosynthetic pathways that allow microbes to survive, and even thrive, in diverse environments. Such pathways allow microbes to extract nutrients from a wide array of substrates, as well as defend themselves from other organisms through 'chemical warfare'. With recent advances in whole genome sequencing and bioinformatics, the microbial world has become a happy hunting ground for the enzymologist who is interested in finding unusual enzymes. This seminar will focus on two programs that are driven by genomics driven discovery of new enzyme reactions. The first involves the enzymatic cleavage of the C-P bonds found in phosphonates, while the second involves the enzymatic synthesis of C-F bonds. Recent advances in these two programs will be presented.
11:30-12:30 BioSci Rm. 3110