title: Developmental and photosynthetic regulation of δ-endotoxin reveals that engineered sugarcane conferring resistance to 'dead heart' contains no toxins in cane juice.
abstract: The phosphoenolpyruvate (PEP) carboxylase is regulated at the levels of transcription and post-translation in C4 plants in light and abundantly accumulates in leaf mesophyll cells. We report here developmental and photosynthetic regulation of stably accumulated Bacillus thuringiensis δ-endotoxin under the control of PEP-C promoter in transgenic sugarcane. In young leaves of plants, the transprotein is accumulated to 39% of the levels in mature leaves (135 ng mg(-1)), and is induced with the cell development, from base to tip. Nevertheless, these levels are decreased up to 99.98% in non-photosynthetic cells as cane matures, from top to bottom, suggesting the photosynthesis regulation of δ-endotoxin in cane cells. Further, transgenic plants are highly resistant to 'dead heart'. In these studies, Scirpophaga nivela larvae causing 'dead heart' were killed within one hour of release to the transgenic plants. Therefore, this report may be regarded as the first report that provides a better strategy for developing transgenic sugarcane lines with absolute protection against invading larvae and no toxin residues in cane juice.
authors.affiliation: National Institute for Biotechnology and Genetic Engineering (NIBGE), Jhang Road, PO Box 577, Faisalabad, 38000, Pakistan. sarwarkhan_40@hotmail.com
authors.forename: Muhammad Sarwar
authors.initials: MS
authors.lastname: Khan
authors.forename: Safdar
authors.initials: S
authors.lastname: Ali
authors.forename: Javed
authors.initials: J
authors.lastname: Iqbal
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D004731:Endotoxins / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D005822:Genetic Vectors / Q000235:genetics; D006460:Hemolysin Proteins / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology; D007113:Immunity, Innate / Q000235:genetics*; D007814:Larva / Q000187:drug effects; D009036:Moths / Q000187:drug effects*; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics; D010788:Photosynthesis / Q000235:genetics; D010935:Plant Diseases / Q000469:parasitology*; D018515:Plant Leaves / Q000737:chemistry; D028321:Plant Preparations / Q000737:chemistry*; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D031786:Saccharum / Q000235:genetics*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D017931:DNA Primers; D004731:Endotoxins; D006460:Hemolysin Proteins; D028321:Plant Preparations; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D010730:Phosphoenolpyruvate Carboxylase