2012 journal article
An ER-targeted calcium-binding peptide confers salt and drought tolerance mediated by CIPK6 in Arabidopsis
PLANTA, 235(3), 539–552.
author keywords: ER calcium; Calcium-binding peptide (CBP); CBL-interacting protein kinase (CIPK6); Drought; Salt
MeSH headings : Arabidopsis / drug effects; Arabidopsis / genetics; Arabidopsis / metabolism; Calcium / metabolism; Chlorophyll / metabolism; Droughts; Endoplasmic Reticulum / metabolism; Gene Expression Regulation, Plant; Immunoblotting; Peptides / genetics; Peptides / metabolism; Plant Proteins / genetics; Plant Proteins / metabolism; Plant Roots / drug effects; Plant Roots / genetics; Plant Roots / metabolism; Plants, Genetically Modified / drug effects; Plants, Genetically Modified / genetics; Plants, Genetically Modified / metabolism; Potassium / metabolism; Reverse Transcriptase Polymerase Chain Reaction; Salts / pharmacology; Sodium / metabolism
TL;DR:
This work demonstrates that ER (or nuclear) Ca2+ can directly participate in signal transduction to alter gene expression and the discovery of a method for increasing Ca 2+ levels without deleterious effects on plant growth may have practical applications.
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UN Sustainable Development Goal Categories
2. Zero Hunger
(Web of Science)
13. Climate Action
(Web of Science)
Source: Web Of Science
Added: August 6, 2018
Different plant organelles have high internal stores of Ca(2+) compared to the cytoplasm and could play independent roles in stress responses or signal transduction. We used a GFP fusion with the C-domain of calreticulin, which shows low-affinity, high capacity Ca(2+) binding in the ER, as a calcium-binding peptide (CBP) to specifically increase stores in the ER and nucleus. Despite the presence of a signal sequence and KDEL retention sequence, our work and previous studies (Brandizzi et al. Plant Journal 34:269-281, 2003) demonstrated both ER and nuclear localization of GFP-CBP. Under normal conditions, GFP-CBP-expressing lines had ~25% more total Ca(2+) and higher levels of chlorophyll and seed yield than wild type and GFP controls. CBP-expressing plants also had better survival under intermittent drought or high salt treatments and increased root growth. One member of the CIPK (calcineurin B-like interacting protein kinase) gene family, CIPK6, was up-regulated in CBP-expressing plants, even under non-stress conditions. A null mutation in cipk6 abolished the increased stress tolerance of CBP-transgenic plants, as well as the CBP-mediated induction of two stress-associated genes, DREB1A and RD29A, under non-stress conditions. Although this suggested that it was the induction of CIPK6, rather than localized changes in Ca(2+), that resulted in increased survival under adverse conditions, CIPK6 induction still required Ca(2+). This work demonstrates that ER (or nuclear) Ca(2+) can directly participate in signal transduction to alter gene expression. The discovery of a method for increasing Ca(2+) levels without deleterious effects on plant growth may have practical applications.