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.
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 microbe-associated molecular pattern-induced defense signaling pathway in rice cultured cells.
Kurusu
Takamitsu
T
Department of Applied Biological Science, Tokyo University of Science, Noda, Chiba 278-8510, Japan.
Hamada
Jumpei
J
Nokajima
Hiroshi
H
Kitagawa
Youichiro
Y
Kiyoduka
Masahiro
M
Takahashi
Akira
A
Hanamata
Shigeru
S
Ohno
Ryoko
R
Hayashi
Teruyuki
T
Okada
Kazunori
K
Koga
Jinichiro
J
Hirochika
Hirohiko
H
Yamane
Hisakazu
H
Kuchitsu
Kazuyuki
K
D016923:Cell Death; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000276:immunology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism*; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques; D000094162:Phytoalexins
D018076:DNA, Complementary; D010940:Plant Proteins; D018749:RNA, Plant; D011994:Recombinant Proteins; D012717:Sesquiterpenes; D011494:Protein Kinases; D000094162:Phytoalexins