Shoot formation from root tip region: a developmental alteration by WUS in transgenic tobacco.
We examined the effect of ectopic expression of WUS on the morphology of tobacco seedlings and the segments in vitro. WUS was amplified from Arabidopsis cDNA and introduced into the tobacco genome under the transcriptional control of the beta-estradiol-inducible expression system. When 1-week-old transgenic seedlings were cultured in the presence of beta-estradiol, only the root tip region developed bulbous tissues followed by shoot formation and plant regeneration, suggesting its applicability for improving the strategy of micropropagation in recalcitrant species. Evident abnormality was not observed in the cotyledons, hypocotyl nor root except for the tip. However, ectopic WUS seemed to be functional in those parts through the observation of gene expression and the behavior of cultured segments. Small root segments with a root tip treated with beta-estradiol also showed bulbing but no shoots unless exogenous cytokinin was supplied. These findings suggest the existence of unknown factors regulating ectopic WUS function in the seedling.
Rashid
Syeda Zinia
SZ
Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki, Kagawa 761-0795, Japan.
Yamaji
Naoki
N
Kyo
Masaharu
M
D029681:Arabidopsis Proteins / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology*; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development*; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics*; D019076:Transgenes
D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; C109677:NTH15 protein, Nicotiana tabacum; D010940:Plant Proteins; C116421:WUSCHEL protein, Arabidopsis; D004958:Estradiol