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Title: Potassium nutrient status drives posttranslational regulation of a low-K response network in Arabidopsis
Abstract Under low-potassium (K+) stress, a Ca2+signaling network consisting of calcineurin B-like proteins (CBLs) and CBL-interacting kinases (CIPKs) play essential roles. Specifically, the plasma membrane CBL1/9-CIPK pathway and the tonoplast CBL2/3-CIPK pathway promotes K+uptake and remobilization, respectively, by activating a series of K+channels. While the dual CBL-CIPK pathways enable plants to cope with low-K+stress, little is known about the early events that link external K+levels to the CBL-CIPK proteins. Here we show that K+status regulates the protein abundance and phosphorylation of the CBL-CIPK-channel modules. Further analysis revealed low K+-induced activation of VM-CBL2/3 happened earlier and was required for full activation of PM-CBL1/9 pathway. Moreover, we identified CIPK9/23 kinases to be responsible for phosphorylation of CBL1/9/2/3 in plant response to low-K+stress and the HAB1/ABI1/ABI2/PP2CA phosphatases to be responsible for CBL2/3-CIPK9 dephosphorylation upon K+-repletion. Further genetic analysis showed that HAB1/ABI1/ABI2/PP2CA phosphatases are negative regulators for plant growth under low-K+, countering the CBL-CIPK network in plant response and adaptation to low-K+stress.  more » « less
Award ID(s):
2041585
PAR ID:
10484123
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Nature
Date Published:
Journal Name:
Nature Communications
Volume:
14
Issue:
1
ISSN:
2041-1723
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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