Open AccessEnhancement of Naphthaleneacetic Acid-Induced Rhizogenesis in TL-DNA-Transformed Brassica napus without Significant Modification of Auxin Levels and Auxin Sensitivity
Author(s) -
Jacques H. Julliard,
Bruno Sotta,
Georges Pelletier,
Émile Miginiac
Publication year - 1992
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.100.3.1277
Subject(s) - auxin , explant culture , organogenesis , biology , abscisic acid , shoot , brassica , cytokinin , botany , brassica oleracea , growth regulator , horticulture , regeneration (biology) , in vitro , biochemistry , microbiology and biotechnology , gene
Determination of the abscisic acid and indoleacetic acid (IAA) contents of floral stem segments of nontransformed and pRi A(4) T(L)-DNA-transformed rape (Brassica napus L. var oleifera, cv Brutor) using a high performance liquid chromatography-enzyme-linked immunosorbent assay procedure and mass spectrometry controls showed that IAA levels were not modified. The regeneration abilities of the in vitro cultured explants were compared on media supplemented with several plant growth regulator combinations. No regeneration occurred on hormone-free media, and shoot production was similar in both genotypes when supplemented with benzyladenine. In the presence of naphthaleneacetic acid (NAA), transformed explants were characterized by faster root regeneration and reduced shoot organogenesis. The optimum for root formation was the same in nontransformed and transformed plants, but the sensitivity threshold was slightly lower in the latter. The NAA inductive period was shorter (14 versus 22 h) with transformed tissue. Root neoformation occurred about 72 h earlier on transformed explants. Our results suggest mainly that there is an acceleration of the auxinic signal transduction and/or that the events preliminary to the formation of roots occur faster in the transformed tissues than in the normal ones.