Expression of the Pib rice-blast-resistance gene family is up-regulated by environmental conditions favouring infection and by chemical signals that trigger secondary plant defences.
The rice blast resistance gene Pib is a member of the nucleotide binding site (NBS) and leucine-rich repeat (LRR) class of plant disease resistance (R) genes and belongs to a small gene family. We describe here the isolation and characterization of a Pib homologue (PibH8), and extensive investigation of the expression of the Pib gene family (Pib, PibH8, HPibH8-1, HPibH8-2) under various environmental and chemical treatments. PibH8 shows 42% identity and 60% similarity to Pib and, like Pib, has a duplication of the kinase 1a, 2, and 3a motifs of the NBS region in the N-terminal half of the protein. Interestingly, genes of the Pib family exhibit a diurnal rhythm of expression. RNA gel blot analysis revealed that their expression was regulated dramatically by environmental signals. such as temperature, light and water availability. Their expression was also induced by chemical treatments, such as jasmonic acid, salicylic acid, ethylene and probenazole. Our findings suggest that expression of the Pib gene family is up-regulated by environmental conditions that would favour pathogen infection. This may reflect the evolution of anticipatory control of R gene expression.
Wang
Z X
ZX
Institute of the Society for Techno-Innovation of Agriculture, Forestry and Fisheries, Tsukuba, Ibaraki, Japan.
Yamanouchi
U
U
Katayose
Y
Y
Sasaki
T
T
Yano
M
M
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics*; D003517:Cyclopentanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D005030:Ethylenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D020082:Magnaporthe / Q000254:growth & development; D008969:Molecular Sequence Data; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology; D054883:Oxylipins; D028044:Phosphate-Binding Proteins; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D010940:Plant Proteins; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature; D013844:Thiazoles / Q000494:pharmacology; D015854:Up-Regulation
D002352:Carrier Proteins; D003517:Cyclopentanes; D018076:DNA, Complementary; D005030:Ethylenes; D054883:Oxylipins; D028044:Phosphate-Binding Proteins; C121462:Pib protein, Oryza sativa; C442338:PibH8 protein, Oryza; D010940:Plant Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D013844:Thiazoles; C099063:oryzemate; D012965:Sodium Chloride; C011006:jasmonic acid; D000040:Abscisic Acid; C036216:ethylene; D020156:Salicylic Acid