Characterization of an Oryza sativa MAP kinase gene regulated by enviromental stress

• Main Authors: Tai Ying Hsia, 戴熒霞
• Other Authors: Huang Ding Dinq
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/19394428362515803790

碩士 === 國立成功大學 === 生物學系 === 88 === Mitogen-activated protein kinase（MAPK）pathways are modules involved in the transduction of extracelular signals to intracellular targets in all eukaryotes. In plants, there is evidence for MAPKs playing a role in the signaling of abiotic stresses, pathogens, plant hormones, and cell cycle. The large number and diverce of plant MAPKs indicates that this ancient mechanism of bioinformatic is extensively used in plants. A novel MAPK termed OsMAPK2 was isolated from rice（Oryza sativa）. The cloned cDNA is 1457 nucleotides long and the deduced amino acid sequence comprised 369 amino acid residules. Sequence analysis of OsMAPK2 revealed that the predicted amino acid sequence is 72﹪identical to that of tobacco WIPK. Southern analysis suggested a single OsMAPK2 gene in rice. To study the kinase activity of OsMAPK2, recombinant OsMAPK2 was expressed in E. coli and found that the enzyme displays autophosphorylation on tyrosine. Moreover, mRNA levels of OsMAPK2 increased in response to starvation stress and temperature downshift from 26℃ to 5℃ but decreased in response to 42℃ heat stress. Theses results suggest that OsMAPK2 may function in the stress-activated-signalling pathways in rice. Analysis at the mRNA level has shown that OsMAPK2 is more abundantly expressed in panicles after heading than that in root, stem, young panicles and leaf.