CSB Special Seminar – Alex Costa, PhD – Department of Biosciences, University of Milan
August 1 @ 11:00 am - 12:00 pm
CSB Special Seminar
Alex Costa, PhD
Department of Biosciences, University of Milan
TITLE:
Long-distance turgor pressure changes induce local activation of plant glutamate receptor-like channels
ABSTRACT:
Calcium (Ca2+) signaling is a fundamental process that influences a wide range of physiological activities in plants, operating at cellular, organ, and whole-plant levels. A comprehensive understanding of these signaling mechanisms is vital for decoding the complexities of plant development and their responses to various biotic and abiotic stresses.
In Arabidopsis thaliana, the plant glutamate receptor-like channels (GLRs) family consists of 20 isoforms categorized into three clades. Recent research has illuminated their essential role in mediating long-distance electric and Ca2+ signaling. This, in turn, is crucial for the synthesis of jasmonic acid (JA) and the subsequent activation of JA-dependent signaling pathways, which are key to the plant’s adaptation to stress. While the physiological significance of GLRs is increasingly recognized, the activation mechanisms of these channels and the specific physiological roles of their amino acid binding remain largely unexplored.
This lecture will focus on the role of AtGLR3.3 in Arabidopsis thaliana, particularly in response to local wounding, leaf injury, and osmotic stress. It will reveal that the in vivo activation of the AtGLR3.3 channel and the subsequent systemic responses require a functional ligand-binding domain for the binding of exogenous amino acids. Utilizing an integrated approach combining imaging and genetic analysis, I will demonstrate that mechanical injuries to leaves, such as wounds and burns, as well as hypo-osmotic stress in root cells, lead to a systemic increase in apoplastic L-Glutamate. This increase occurs upstream of AtGLR3.3 activation and is essential for the elevation of cytosolic Ca2+ levels.
HOST: Keiko Yoshioka
LOCATION: Ramsay Wright, 25 Harbord Street, Room 432