Identification and characterization of alternative promoters of the rice MAP kinase gene OsBWMK1.
Our previous study suggested that OsBWMK1, a gene which encodes a member of the rice MAP kinase family, generates transcript variants which show distinct expression patterns in response to environmental stresses. The transcript variants are generated by alternative splicing and by use of alternative promoters. To test whether the two alternative promoters, pOsBWMK1L (promoter for the OsBWMK1L splice variant) and pOsBWMK1S (promoter for the OsBWMK1S splice variant), are biologically functional, we analyzed transgenic plants expressing GUS fusion constructs for each promoter. Both pOsBWMK1L and pOsBWMK1S are biologically active, although the activity of pOsBWMK1S is lower than that of pOsBWMK1L. Histochemical analysis revealed that pOsBWMK1L is constitutively active in most tissues at various developmental stages in rice and Arabidopsis, whereas pOsBWMK1S activity is spatially and temporally restricted. Furthermore, the expression of pOsBWMK1S::GUS was upregulated in response to hydrogen peroxide, a plant defense signaling molecule, in both plant species. These results suggest that the differential expression of OsBWMK1 splice variants is the result of alternative promoter usage and, moreover, that the mechanisms controlling OsBWMK1 gene expression are conserved in both monocot and dicot plants.
Koo
Sung Cheol
SC
Division of Applied Life Science, Graduate School of Gyeongsang National University, Jinju, Korea.
Choi
Man Soo
MS
Chun
Hyun Jin
HJ
Park
Hyeong Cheol
HC
Kang
Chang Ho
CH
Shim
Sang In
SI
Chung
Jong Il
JI
Cheong
Yong Hwa
YH
Lee
Sang Yeol
SY
Yun
Dae-Jin
DJ
Chung
Woo Sik
WS
Cho
Moo Je
MJ
Kim
Min Chul
MC
D017398:Alternative Splicing; D001483:Base Sequence; D015153:Blotting, Western; D005786:Gene Expression Regulation; D014644:Genetic Variation; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000235:genetics*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms
D010940:Plant Proteins; D020033:Protein Isoforms; C403286:MPK12 protein, Oryza sativa; D020928:Mitogen-Activated Protein Kinases