Title : Roles of reactive oxygen species in plant growth and defence.
Speaker : Prof. Christine H. Foyer, University of Birmingham.
Date : 14/09/2022, 05:30 PM , Online Mode.
Reactive oxygen species (ROS) play a key role in stress responses and developmental pathways in all living organisms. The level of ROS molecules is controlled by different antioxidant enzymes as well as non-enzymatic antioxidants. Considerable progress has been made in our understanding of the nature hydrogen peroxide sensors and the role of thiol dependent signalling networks in the transmission of ROS signals. In this talk, I will discuss current concepts regarding the ROS functions in the control of growth and defence and how redox-regulated processes interact with other cell signalling systems. I will focus on the example of how plant growth promoting rhizobacteria (PGPR) regulate root development and root system architecture (RSA) in Arabidopsis thaliana. Significant increases in lateral root (LR) number and LR density were observed when seedlings were grown in the presence of oryzihabitans. These changes did not appear to be triggered by volatile signals. The presence of P. oryzihabitans changed the levels of root transcripts associated with nutrition, oxidative stress responses and ethylene signalling. The P. oryzihabitans-induced changes in wild type (WT) root RSA were absent from mutants lacking ethylene response factor (ERF109) and mutants defective in strigolactone (SL) synthesis (max3-9 and max4-1) or signalling (max2-3). Mutants that are defective in antioxidant capacity (vtc2-1, vtc2-2, pad2-1, cad2-1 and rax1-1) also showed less significant responses in RSA to P. oryzihabitans than the wild type (WT) roots. These results demonstrate the importance of the integration of redox and phytohormone signals in root responses to P. oryzihabitans.
Christine H. Foyer is Professor of Plant Sciences at the University of Birmingham (UK). She is the President of the Association of Applied Biologists and a Member of the French Academy of Agriculture. She is also the Editor in Chief of Food and Energy Security and has been an elected Board Member of the American Society of Plant Biologists for the past four years. She is a senior Editor for Plant, Cell and Environment and an Associate Editor of the Biochemical Journal, The Journal of Experimental Biology and Physiology Plantarum. Christine has over 400 published papers and currently has an H-Index over 100. She is on the Thomson Reuters IP and Science official list of Highly Cited Researchers ranked within the top 1% most cited works for their subject field and year of publication, earning a mark of Exceptional Impact. Christine is an expert in plant metabolism and its regulation under optimal and stress conditions. Her lab focuses on the role of reduction/oxidation (redox) processes and signals regulate plant growth and stress tolerance, studying how primary processes (photosynthesis respiration) alter the redox status of cells and associated phytohormone signalling under optimal and stress conditions. Using model (Arabidopsis) as well as crop plants (wheat, barley, maize soybean and tomato) the lab investigates plant responses to abiotic (drought, heat, chilling, high light) and biotic (aphids) stresses.