Induction of hairy roots and characterization of peroxidase expression as a potential root growth marker in sesame.
Using hypocotyl and cotyledon of sesame seedlings, hairy root cultures were established and cDNA coding for a peroxidase was cloned from the roots. The frequency of sesame hairy root formation was higher in hypocotyl (33.4%) than cotyledon (9.3%). Applicable levels of kanamycin and hygromycin as a selectable marker were 100 microg/mL and 30 microg/mL, respectively. The peroxidase cDNA showed relatively high sequence identity with and similarity to plant class III peroxidase family. The cDNA encoded polypeptide was identified with the presence of three sequence features: 1) the putative 4 disulfide bridges, 2) an ER-targeted signal sequence in the N-terminus, and 3) two triplets, NXS for glycosylation. A real-time RT-PCR exhibited an abrupt increase in the peroxidase transcription activity after 4-week cultures of the sesame hairy roots and its highest level in 6-week cultured hairy roots. In contrast, the growth pattern of sesame hairy roots showed a typical sigmoidal curve. The active hairy root growth began after 2-week culture and their stationary growth phase occurred after 5-week culture. These results suggested that the peroxidase expression patterns at its transcription level could be used a potential indicator signaling a message that there will be no longer active growth in hairy root cultures. The sesame peroxidase gene was differentially expressed in different tissues.
Chun
J-A
JA
Department of Biotechnology, Dong-A University, Busan, South Korea.
Lee
J-W
JW
Yi
Y-B
YB
Park
G-Y
GY
Chung
C-H
CH
D009195:Peroxidase / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development* / Q000382:microbiology; D012231:Rhizobium / Q000502:physiology; D036226:Seedlings / Q000201:enzymology* / Q000254:growth & development* / Q000382:microbiology; D031685:Sesamum / Q000201:enzymology* / Q000254:growth & development* / Q000382:microbiology
D009195:Peroxidase