Mitogen-activated protein kinase cascade in the signaling for polyamine biosynthesis in tobacco.
Expression of NtNEK2(DD), a constitutively active mutant of NtMEK2, activates endogenous salicylic acid-induced protein kinase (SIPK) and wounding-induced protein kinase (WIPK), and leads to several stress/defense responses in tobacco. In this study, we used ACP (annealing control primer)-based differential display reverse transcription-PCR to isolate the downstream effectors mediated by the NtMEK2-SIPK/WIPK cascade. The arginine decarboxylase gene (ADC), which is involved in plant putrescine biosynthesis, was one of nine differentially expressed genes. When compared with NtMEK2(KR) plants, NtMEK2(DD) transgenic plants exhibited a significant increase in ADC and ODC (ornithine decarboxylase) transcript levels, as well as in putrescine and its catabolite, gamma-aminobutyric acid, following SIPK/WIPK activation. Taken together, these results suggest that the NtMEK2-SIPK/WIPK cascade is involved in regulating polyamine synthesis, especially putrescine synthesis, through transcriptional regulation of the biosynthetic genes in tobacco.
Jang
Eun-Kyoung
EK
Agricultural Plant Stress Research Center, Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea.
Min
Kwang-Hyun
KH
Kim
Su-Hyun
SH
Nam
Seung-Hee
SH
Zhang
Shuqun
S
Kim
Young Cheol
YC
Cho
Baik Ho
BH
Yang
Kwang-Yeol
KY
D002262:Carboxy-Lyases / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D048370:MAP Kinase Kinase 2 / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000235:genetics*; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics; D014158:Transcription, Genetic
D010940:Plant Proteins; D011073:Polyamines; D020928:Mitogen-Activated Protein Kinases; C106405:SA-induced protein kinase; D048370:MAP Kinase Kinase 2; D002262:Carboxy-Lyases; C019722:arginine decarboxylase