Regulation of Microbe-Associated Molecular Pattern-Induced Hypersensitive Cell Death, Phytoalexin Production, and Defense Gene Expression by Calcineurin B-Like Protein-Interacting Protein Kinases, OsCIPK14/15, in Rice Cultured Cells    

Abstract

Although cytosolic free Ca 2+ mobilization induced by microbe/pathogen-associated molecular patterns is postulated to play a pivotal role in innate immunity in plants, the molecular links between Ca 2+ and downstream defense responses still remain largely unknown. Calcineurin B-like proteins (CBLs) act as Ca 2+ sensors to activate specific protein kinases, CBL-interacting protein kinases (CIPKs). We here identified two CIPKs, OsCIPK14 and OsCIPK15, rapidly induced by microbe-associated molecular patterns, including chitooligosaccharides and xylanase (Trichoderma viride/ethylene-inducing xylanase [TvX/EIX]), in rice (Oryza sativa). Although they are located on different chromosomes, they have over 95% nucleotide sequence identity, including the surrounding genomic region, suggesting that they are duplicated genes. OsCIPK14/15 interacted with several OsCBLs through the FISL/NAF motif in yeast cells and showed the strongest interaction with OsCBL4. The recombinant OsCIPK14/15 proteins showed Mn 2+ -dependent protein kinase activity, which was enhanced both by deletion of their FISL/ NAF motifs and by combination with OsCBL4. OsCIPK14/15-RNAi transgenic cell lines showed reduced sensitivity to TvX/EIX for the induction of a wide range of defense responses, including hypersensitive cell death, mitochondrial dysfunction, phytoalexin biosynthesis, and pathogenesis-related gene expression. On the other hand, TvX/EIX-induced cell death was enhanced in OsCIPK15-overexpressing lines. Our results suggest that OsCIPK14/15 play a crucial role in the microbeassociated molecular pattern-induced defense signaling pathway in rice cultured cells.Calcium ions regulate diverse cellular processes in plants as a ubiquitous internal second messenger, conveying signals received at the cell surface to the inside of the cell through spatial and temporal concentration changes that are decoded by an array of Ca 2+

Glutathione-Indole-3-Acetonitrile Is Required for Camalexin Biosynthesis in Arabidopsis thaliana

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Plant defense response against Fusarium oxysporum and strategies to develop tolerant genotypes in banana

“…Several studies (Kobayashi et al 2007;Kurusu et al 2010) have demonstrated that CBL-CIPK system produce ROS against elicitors (TvX/eIX). However, there were no studies on CBL-CIPK involvement specifically against Fox till date.…”

Signals that stop the rot: Regulation of secondary metabolite defences in cereals

“…Signals from cellular Ca 2+ are interpreted by calcium sensors, such as calcineurin B-like proteins (CBLs), which subsequently activate CBL interacting protein kinases (CIPKs) [67]. The expression of two rice CIPKs, OsCIPK14 and OSCIPK15, was induced by N-acetylchitooligosaccharides in rice cells and resulted in rapid accumulation of momilactones and phytocassanes ( Figure 1A) [67].…”

“…Yang et al (2004) demonstrated that application of calcium channel blockers diminished the accumulation of avenanthramides, which led them to believe that calcium ions were critical to the activation of oat phytoalexin production [66]. Signals from cellular Ca 2+ are interpreted by calcium sensors, such as calcineurin B-like proteins (CBLs), which subsequently activate CBL interacting protein kinases (CIPKs) [67]. The expression of two rice CIPKs, OsCIPK14 and OSCIPK15, was induced by N-acetylchitooligosaccharides in rice cells and resulted in rapid accumulation of momilactones and phytocassanes ( Figure 1A) [67].…”