Enhanced disease resistance conferred by expression of an antimicrobial magainin analog in transgenic tobacco

Abstract

Magainins are a group of short peptides originally isolated from frog skin and thought to function as a natural defense mechanism against infection due to their antimicrobial properties. The engineered magainin analog peptide Myp30 was found to inhibit spore germination of the oomycete, Peronospora tabacina (Adam) in vitro, and the growth of a bacterial pathogen Erwinia carotovora subsp. carotovora (Jones). Transgenic tobacco (Nicotiana tabacum L.) plants expressing Myp30 were evaluated for resistance to these pathogens. The expression of the peptide only to an extracellular location resulted in significant reduction in sporulation and lesion size due to P. tabacina infection. A significant increase in resistance to the bacterial pathogen was also observed regardless of the targeting location of the peptide.

Involvement of the Pepper Antimicrobial Protein CaAMP1 Gene in Broad Spectrum Disease Resistance

“…Strategies to enhance plant disease resistance based on transgenic approaches have used genes associated with plant defense pathways (Makandar et al, 2006;Zhang et al, 2007), genes encoding plant or fungal hydrolytic enzymes (Lorito et al, 1998;Bieri et al, 2003), and genes encoding defense-related transcription factors (Chen and Chen, 2002;Sohn et al, 2006) and antimicrobial proteins (DeGray et al, 2001;Li et al, 2001). The accumulation of PR proteins represents a major quantitative change in protein composition that occurs during the hypersensitive response (HR), leading to the synthesis of low molecular weight compounds, proteins, and peptides with antimicrobial activity (Fritig et al, 1998).…”

Transformação genética de laranja doce (Citrus sinensis L. Osbeck) com o gene D4E1 dirigido pelos promotores CaMV35S ou AtPP2

“…Segundo alguns autores esta dificuldade está associada à característica anfipática do peptídeo D4E1, que leva a agregação e incapacidade do peptídeo migrar pelo gel de SDS-PAGE (RAJAZEKARAN et al, 2005). A mesma dificuldade foi relatada em outros trabalhos com pequenos peptídeos, como o D4E1 que tem peso molecular aproximado de 2kDa (LI et al, 2001). …”

Potential of chloroplast genome in plant breeding

“…These data suggest that MSI-99 expressed in tobacco chloroplasts can offer significant protection from both bacterial and fungal pathogens. By contrast, when the same MSI-99 was expressed via the nuclear genome, it did not confer adequate disease resistance against these pathogens due to low levels of expression (Li et al 2001).…”