70 likes | 197 Views
Lecture 11 &12. Virus resistant plants. Expression of dsRNase(RNaseIII). wheat engineered to express the E. coli gene for ribonuclease (RNase) III most plant viruses have double-stranded RNA a mutant of RNase III was used the mutant enzyme able to bind to double-stranded RNA
E N D
Lecture 11 &12 Virus resistant plants
Expression of dsRNase(RNaseIII) • wheat engineered to express the E. coli gene for ribonuclease (RNase) III • most plant viruses have double-stranded RNA • a mutant of RNase III was used • the mutant enzyme able to bind to double-stranded RNA • introduced into wheat, under the control of a corn ubiquitin gene (Fig. 4), by micro- projectile bombardment • transgenic plants resistance to infection by barley stripe mosaic virus
Genetic construct used to transform wheat plantswith the gene for the mutant form of E. coli RNase III. The construct includes the maize ubiquitin promoter, first exon and intron in front of a mutant form of E. coli RNase III and a transcription terminator region from a nopaline synthase gene
Expression of antiviral proteins • pokeweed (Phytolacca americana) -3 antiviral proteins in its cell wall • pokeweed antiviral protein PAPI-in spring leaves; • PAPII-in summer leaves; and PAP-S-in seeds • Both PAP and PAPII are ribosome-inactivating proteins • remove a specific adenine residue from the large ribosomal RNA • pokeweed plants infected with viruses, either PAP or PAPII is synthesized • PAP and PAP II are good candidates for developing transgenic plants resistant to a broad spectrum of plant viruses