Isolation and expression of a novel starch-storing cell-specific gene containing the KH RNA binding domain from tobacco-cultured cells BY-2.
In cultured Bright Yellow-2 tobacco (Nicotiana tabacum) cells, the depletion of 2,4-dichlorophenoxyacetic acid (2,4-D) in the culture medium induces amyloplast development. This differentiation also includes a decrease in cell multiplication, and an increase in cell size. These changes were primarily triggered by the depletion of 2,4-D, and accelerated by the addition of benzyladenine (BA). Three cDNAs were identified whose transcript levels are specifically increased during differentiation of starch-storing cells using the differential display method, and designated as starch-storing cell induced genes (SCI genes). One of these cDNAs, SCI2 encodes a 285 amino acids long protein with a KH RNA-binding domain. A database search revealed that this protein showed similarity to respective domains of mammalian quaking proteins. 2,4-D addition, which can convert starch-storing cells into dividing cells, to starch-storing BY-2 cells, immediately decreases the SCI2 transcript level, suggesting that SCI2 may have some role in starch-storing cell differentiation in BY-2 cells.
Miyazawa
Yutaka
Y
Plant Functions Laboratory, RIKEN, Hirosawa, Wako-shi, Saitama, 351-0198, Japan. yutakam@postman.riken.go.jp
Sakai
Atsushi
A
Matsunaga
Sachihiro
S
Asami
Tadao
T
Kawano
Shigeyuki
S
Kuroiwa
Tsuneyoshi
T
Yoshida
Shigeo
S
D015084:2,4-Dichlorophenoxyacetic Acid / Q000008:administration & dosage; D015152:Blotting, Northern; D002478:Cells, Cultured; D003470:Culture Media; D018076:DNA, Complementary; D017343:Genes, Plant; D008969:Molecular Sequence Data; D016601:RNA-Binding Proteins / Q000235:genetics*; D013213:Starch / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
D003470:Culture Media; D018076:DNA, Complementary; D016601:RNA-Binding Proteins; D015084:2,4-Dichlorophenoxyacetic Acid; D013213:Starch