Girdhar K. Pandey

Friday Seminar by Mr. Pavithran Narayanan

GKP Lab/ Friday/ Feburary 15, 2019/ 3.30 pm/ Waves of information: Calcium and ROS  in systemic Signalling
Category: Research
Posted by: bedineel

Waves of Information: Calcium and ROS in Systemic Signalling

Systemic signalling is a well-documented process in plants, especially in response to biotic stresses like pathogen infestation, where information about the stress is radiated out from the site of application. This long-distance communication depends on signals that travel, cell-to-cell, from one part of the plant to another. Although the molecular mechanisms governing systemic signalling during microbial infection has been studied well, knowledge of the same under abiotic stresses is sparse. A breakthrough study has identified a wave of Calcium (Ca2+) ions moving shootwards when local salinity stress is applied to the root tips of Arabidopsis plants. This signal has been found to be travelling at a rate of about 400µm/s, selectively through the cortex and endodermal tissue layers of the root and is blocked when pharmacological inhibitors of Ca2+ channels are applied upstream of the site of stress application. Further work, along with mathematical modelling, has also shown that this Ca2+ wave is coupled to a simultaneous wave of Reactive Oxygen Species (ROS) in a phenomenon of ROS-dependent Calcium Induced Calcium Release (CICR). While the Ca2+ wave probably moves via plasmodesmata and depends on the cation-selective Two Pore Channel (TPC1), the ROS wave travels through the apoplast and depends upon RBOHD. These studies may prime future research to get a broad understanding about the process of Systemic Acquired Acclimation (SAA) in plants