title: Role of intron-mediated enhancement on accumulation of an Arabidopsis NB-LRR class R-protein that confers resistance to Cucumber mosaic virus.
abstract: The accumulation of RCY1 protein, which is encoded by RESISTANCE TO CMV(Y) (RCY1), a CC-NB-LRR class R-gene, is tightly correlated with the strength of the resistance to a yellow strain of Cucumber mosaic virus [CMV(Y)] in Arabidopsis thaliana. In order to enhance resistance to CMV by overexpression of RCY1, A. thaliana was transformed with intron-less RCY1 cDNA construct under the control of strong CaMV35S promoter. Remarkably, a relative amount of RCY1 protein accumulation in the transformants was much lower than that in plants expressing genomic RCY1 under the control of its native promoter. To identify a regulatory element of RCY1 that could cause such differential levels of RCY1 accumulation, a series of RCY1 cDNA and genomic RCY1 constructs were transiently expressed in Nicotiana benthamiana leaves by the Agrobacterium-mediated infiltration method. Comparative analysis of the level of RCY1 accumulation in the leaf tissues transiently expressing each construct indicated that the intron located in the RCY1-coding region of genomic RCY1, but not the native RCY1 genomic promoter or the 5'-and 3'-untranslated regions of RCY1, was indispensable for high level RCY1 accumulation. The increased levels of RCY1 accelerated plant disease defense reactions. Interestingly, such intron-mediated enhancement of RCY1 accumulation depended neither on the abundance of the RCY1 transcript nor on the RCY1 specific-intron sequence. Taken together, intron-mediated RCY1 expression seems to play a key role in the expression of complete resistance to CMV(Y) by maintaining RCY1 accumulation at high levels.
authors.affiliation: Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Yukiyo
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Sugihiro
authors.initials: S
authors.lastname: Ando
authors.affiliation: Department of Applied Plant Science, Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D060054:Agrobacterium / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D017799:Cucumovirus / Q000276:immunology*; D018076:DNA, Complementary / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics*; D060146:Ecotype; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics; D007438:Introns / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D018515:Plant Leaves / Q000235:genetics / Q000821:virology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D014026:Nicotiana / Q000276:immunology / Q000382:microbiology; D014170:Transformation, Genetic; D019076:Transgenes / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; C473790:RCY1 protein, Arabidopsis; D012333:RNA, Messenger; D000068103:Serine-Arginine Splicing Factors