Cosuppression of NtmybA1 and NtmybA2 causes downregulation of G2/M phaseexpressed genes and negatively affects both cell division and expansion in tobacco.
During the plant cell cycle, genes preferentially expressed at the G2/M phase are regulated by R1R2R3-type Myb transcription factors. To address the function of 2 tobacco R1R2R3-Myb proteins, NtmybA1 and NtmybA2, we generated transgenic tobacco plants in which endogenous NtmybA2 transcripts were significantly decreased, presumably due to cosuppression triggered by the presence of the NtmybA2 transgene. These lines showed a concomitant downregulation of structurally related NtmybA1 and many G2/M-expressed genes. In the cosuppression plants, we found a dwarf phenotype due to both reduced cell size and decreased cell number. Our results provide evidence confirming our previous view that NtmybA1 and NtmybA2 may regulate cell expansion as well as cell division by transcriptionally activating many G2/M-expressed genes in tobacco.
Satoshi
S
Araki
Kiichi
K
Kato
Toshiya
T
Suzuki
Toru
T
Okumura
Yasunori
Y
Machida
Masaki
M
Ito
D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D016195:G2 Phase / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*
D010940:Plant Proteins