Seminar am MPIPZ

Special Seminar by Ru Zhang, Donald Danforth Plant Science Center, USA

Title: Exploring functional genomic landscapes of heat sensing in photosynthetic cells by using algal high-throughput and quantitative approaches

Host: Paul Schulze-Lefert

Abstract:
Heat stress jeopardizes plant growth, reduces crop yields, and hinders biofuel production. This problem will only exacerbate as global warming progresses. Despite this, the mechanisms employed by photosynthetic cells to sense and regulate heat responses remain poorly understood. To engineer heat-tolerant crops and algae for food and biofuel, a thorough understanding of how plant cells perceive and respond to heat stress is required. The eukaryotic, unicellular green alga Chlamydomonas reinhardtii is an excellent model organism to study many important cellular processes, e.g. photosynthesis, cell cycle, abiotic stresses and others. It has several prominent advantages that are conducive to studying heat sensing and regulation in photosynthetic cells. A genome-saturating, indexed mutant library of Chlamydomonas has recently be generated and maintained, enabling both reverse and forward genetic screens. Besides the mapped insertion site, each mutant has a unique DNA barcode inserted in the genome, allowing for quantitative tracking of growth rates of individual mutants in pooled cultures. We employed the genome-saturating algal mutant library of Chlamydomonas and the quantitative phenotyping tool to screen for algal mutants with altered sensitivities to various heat treatments by varying the levels of temperature, carbon, light, and stress duration. Through this genome-wide screen, a near comprehensive list of genes involved in heat responses was generated. We are using the gene list to identify novel components that are important for heat sensing and regulation in photosynthetic cells. Selective heatsensitive or heat-resistant mutants identified in the screens will be investigated to elucidate gene functions. This study will help understand functional genetics and cellular mechanisms that govern heat sensing and responses in Chlamydomonas. It will provide information for engineering thermotolerant algal strains for biofuel. In addition, the information gained in Chlamydomonas can be transformed into land plants to improve crop thermotolerance and yield.