Regeneration of sugarcane elite breeding lines and engineering of stem borer resistance.
Five elite sugarcane breeding lines were tested for efficiency in embryogenesis and plant regeneration. All of them produced regenerative embryogenic calli but with varied efficiencies. To engineer strongly insect-resistant sugarcanes, the GC content of a truncated cry1Ac gene, which encodes the active region of Cry1Ac insecticidal delta-endotoxin, was increased from the original 37.4 to 47.5% following the sugarcane codon usage pattern. The synthetic cry1Ac gene (s-cry1Ac) was placed under the control of maize ubiquitin promoter and introduced by microprojectile bombardment into the embryogenic calli of sugarcane lines YT79-177 and ROC16. Southern blotting analysis showed that multicopies of s-cry1Ac were integrated into the genomes of transgenic sugarcane lines. Immunoblotting analysis identified 18 transgenic lines expressing detectable levels of s-Cry1Ac, which were estimated in the range of 1.8-10.0 ng mg(-1) total soluble proteins. Four transgenic and two parental lines were assayed for sugarcane stem borer resistance in leaf tissue feeding trials and greenhouse plant assays. The results showed that, while the untransformed control lines were severely damaged in both leaves and stems, the transgenic sugarcane lines expressing high levels of s-Cry1Ac proteins were highly resistant to sugarcane stem borer attack, resulting in complete mortality of the inoculated insects within 1 week after inoculation.
Weng
Li-Xing
LX
Institute of Molecular and Cell Biology, Proteos, 61 Biopolis Drive, Singapore 138673.
Deng
Haihua
H
Xu
Jin-Ling
JL
Li
Qi
Q
Wang
Lian-Hui
LH
Jiang
Zide
Z
Zhang
Hai Bao
HB
Li
Qiwei
Q
Zhang
Lian-Hui
LH
D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D001427:Bacterial Toxins / Q000235:genetics*; D001482:Base Composition; D019470:Biolistics; D001947:Breeding; D017796:Caulimovirus / Q000235:genetics; D004731:Endotoxins / Q000235:genetics* / Q000502:physiology; D015870:Gene Expression; D006460:Hemolysin Proteins; D007814:Larva; D009036:Moths; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D031786:Saccharum / Q000235:genetics* / Q000469:parasitology / Q000502:physiology; D014170:Transformation, Genetic; D025822:Ubiquitin C / Q000235:genetics; D003313:Zea mays
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D010940:Plant Proteins; C417884:Ubi-1 protein, Zea mays; D025822:Ubiquitin C; C030956:insecticidal crystal protein, Bacillus Thuringiensis