Transgenic rice lines expressing rice endochitinase (Chi11) confers improved resistance to Sheath blight and rice blast fungal pathogens

  • Unique Paper ID: 155245
  • Volume: 9
  • Issue: 1
  • PageNo: 330-349
  • Abstract:
  • Rice is the most important staple food crop for more than half of the world population. The global production needs to be doubled to meet the demand. But the major challenge is the increased severe crop loss due to insects and diseases. Among which rice blast caused by Magnaporthe grisea and sheath blight caused by Rhizoctonia solani, is considered are the most devastating diseases in different rice-growing regions of the world. Most of the productive high quality rice varieties presently cultivated in India lack durable resistance to major fungal and bacterial pathogens, such as, M. grisea and R. solani. In the present study, rice endochitinase (Chi11) has been introduced into commercial indica rice variety by Agrobacterium-mediated genetic transformation. Transgenic rice plants were regenerated from the phosphinothricin (PPT) - resistant calli obtained after co-cultivation with Agrobacterium strain LBA4404 harbouring Ti plasmid pSB111-bar-Chi11. Molecular analyses confirmed the stable integration and expression of Chi11 in various transgenic rice lines. Transgenes Chi11 and bar were stably inherited and disclosed co-segregation in T1 generation in a Mendelian fashion. Segregation analysis of T2 progenies using PPT test disclosed monogenic (1:2:1) genotypic inheritance of transgenes. Different Chi11 transgenic lines exhibited ~ 14 to 43 fold higher specific activity of endochitinase than that of untransformed control plants. Homozygous transgenic rice lines expressing CHI11 protein displayed enhanced resistance to rice blast and sheath blight diseases. This is the first report of its kind dealing with the transgenic indica rice exhibiting high resistance to two major fungal pathogens. These transgenic rice lines appear promising and might serve as a novel genetic resource in rice breeding aimed at durable resistance against various pathogens.

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