Agepati Raghavendra
University of Hyderabad India
Prof. Agepati S. Raghavendra is currently an Institution of Eminence (IoE) Research Chair Professor in LifeSciences at University of Hyderabad, India. He was elected as a Corresponding Member in 2012. He is an elected fellow of all four science Academies in India: the Indian National Science Academy, the National Academy of Sciences India, the Indian Academy of Sciences, the National Academy of Agricultural Sciences, and the Third World Academy of Sciences. Professor Raghavendra held the positions of JC Bose National Fellow, DFG Mercator Visiting Professor (Germany), AvH Fellow, and JSPS Senior Visiting Scientist(Japan). He elucidated the role of several guard cell signalling components, including the cytoplasmic pH, during stomatal closure. His other research interests include the essentiality of mitochondrial respiration for optimising photosynthesis and biochemical cross-talk between plant cell organelles.
Title of presentation
The rise in pH of guard cells: An intriguing component of stomatal closure
Authors
Agepati S. Raghavendra , Pulimamidi Bharath, Shashibhushan Gahir
School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
Abstract
Stomatal movements are associated with pH changes in guard cells. Several authors have demonstrated that cytosolic alkalinization preceded the rise in ROS or Ca2+of guard cells. In contrast, a few reports suggest that the increase in cytosolic pH follows the elevated ROS or Ca2+, suggesting that cytosolic pH rise may not always be an early event. The components, such as ROS, Ca2+, and Ca2+-dependent protein kinases, converge to modulate ion channels, promote ion efflux from guard cells and promote stomatal closure. We propose a hypothetical model to integrate the event of pH rise with other signalling components and explain the argument that cytosolic alkalization can occur downstream or upstream of ROS or Ca2+-rise. Changes in guard cell pH can occur when ATPases are modulated. Stomatal closure and guard cell pH rise are compromised in mutants deficient in vacuolar H+-ATPase (V-ATPase), pointing out the role of V-ATPase. My talk attempts to consider arguments for and against the significance of cytosolic alkalinization in guard cells. Stomatal guard cells are promising model systems for further research into this intriguing topic of cytosolic pH change during stomatal closure.
My Sessions
The rise in pH of guard cells: An intriguing component of stomatal closure
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Presentation