Role of Potassium in Plants by Girdhar K. Pandey & Swati Mahiwal

Author:Girdhar K. Pandey & Swati Mahiwal
Language: eng
Format: epub
ISBN: 9783030459536
Publisher: Springer International Publishing

Potassium in Opening and Closing of Stomata

One of the major players for osmosis-dependent guard cell movement is K+. Opening of stomata is a result of increased K+ influx and hyperpolarization of guard cell membrane through activation of H+-ATPases along with sequential activation of inward-rectifying K+ channels KAT1 and KAT2. Opposite events are involved in stomata closure; inhibition of H+-ATPases activates outward-rectifying K+ channel GORK increasing K+ efflux and stomata closure. Opening and closing of stomata is regulated by a vast number of signal transduction pathways (Fig. 5.1) (Sharma et al. 2013). Two-third of K+ channels such as AKT2, KAT1, KAT2, AKT1, AtKC1 and GORK are known to regulate opening and closing of stomata (Szyroki et al. 2001; Ivashikina et al. 2005; Lebaudy et al. 2008; Sharma et al. 2013). A phosphorylation-dependent regulation of KAT1 at its C-terminus (Thr306 and Thr308) by the ABA-activated kinase OPEN STOMATA1 (OST1) has been shown (Sato et al. 2009). KAT2 is known to contribute to stomata closure exclusively. KAT1 and KAT2 are known to homomerize and dimerize in various permutation and combinations with other members of the shaker channel family for the formation of inward K+ channel in guard cell (Lebaudy et al. 2010). Phytohormone abscisic acid (ABA) plays a vital role in this process as it is responsible for the induction of three events in the guard cell, depolarization of guard cell membrane, GORK expression and GORK-mediated K+ efflux (Munemasa et al. 2015).

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.