"HAIRY CANOLA"--Arabidopsis GL3 induces a dense covering of trichomes on Brassica napus seedlings.
Transformation with the Arabidopsis bHLH gene 35S:GLABRA3 (GL3) produced novel B. napus plants with an extremely dense coverage of trichomes on seedling tissues (stems and young leaves). In contrast, trichomes were strongly induced in seedling stems and moderately induced in leaves of a hairy, purple phenotype transformed with a 2.2 kb allele of the maize anthocyanin regulator LEAF COLOUR (Lc), but only weakly induced by BOOSTER (B-Peru), the maize Lc 2.4 kb allele, or the Arabidopsis trichome MYB gene GLABRA1 (GL1). B. napus plants containing only the GL3 transgene had a greater proportion of trichomes on the adaxial leaf surface, whereas all other plant types had a greater proportion on the abaxial surface. Progeny of crosses between GL3+ and GL1+ plants resulted in trichome densities intermediate between a single-insertion GL3+ plant and a double-insertion GL3+ plant. None of the transformations stimulated trichomes on Brassica cotyledons or on non-seedling tissues. A small portion of bHLH gene-induced trichomes had a swollen terminal structure. The results suggest that trichome development in B. napus may be regulated differently from Arabidopsis. They also imply that insertion of GL3 into Brassica species under a tissue-specific promoter has strong potential for developing insect-resistant crop plants.
Gruber
M Y
MY
Agriculture and Agri-Food Canada, Saskatoon Research Centre, 107 Science Place, Saskatoon, SK S7N 0X2, Canada. gruberm@agr.gc.ca
Wang
S
S
Ethier
S
S
Holowachuk
J
J
Bonham-Smith
P C
PC
Soroka
J
J
Lloyd
A
A
D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000502:physiology*; D015152:Blotting, Northern; D029688:Brassica napus / Q000235:genetics / Q000254:growth & development*; D022081:Cell Surface Extensions / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D019441:Plant Epidermis / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000254:growth & development*; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology
D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; C417284:GL3 protein, Arabidopsis; C083017:R-S protein, Zea mays; C500589:Myb protein, Arabidopsis