Transgenic rice plants expressing the antifungal AFP protein from Aspergillus giganteus show enhanced resistance to the rice blast fungus Magnaporthe grisea.
The Aspergillus giganteus antifungal protein (AFP), encoded by the afp gene, has been reported to possess in vitro antifungal activity against various economically important fungal pathogens, including the rice blast fungus Magnaporthe grisea. In this study, transgenic rice ( Oryza sativa ) constitutively expressing the afp gene was generated by Agrobacterium -mediated transformation. Two different DNA constructs containing either the afp cDNA sequence from Aspergillus or a chemically synthesized codon-optimized afp gene were introduced into rice plants. In both cases, the DNA region encoding the signal sequence from the tobacco AP24 gene was N-terminally fused to the coding sequence of the mature AFP protein. Transgenic rice plants showed stable integration and inheritance of the transgene. No effect on plant morphology was observed in the afp -expressing rice lines. The inhibitory activity of protein extracts prepared from leaves of afp plants on the in vitro growth of M. grisea indicated that the AFP protein produced by the trangenic rice plants was biologically active. Several of the T(2) homozygous afp lines were challenged with M. grisea in a detached leaf infection assay. Transformants exhibited resistance to rice blast at various levels. Altogether, the results presented here indicate that AFP can be functionally expressed in rice plants for protection against the rice blast fungus M. grisea.
Coca
María
M
Departamento de Genética Molecular, Instituto de Biología Molecular de Barcelona, CID-CSIC, Jordi Girona 18, 08034 Barcelona, Spain.
Bortolotti
Cristina
C
Rufat
Mar
M
Peñas
Gisela
G
Eritja
Ramón
R
Tharreau
Didier
D
del Pozo
Alvaro Martinez
AM
Messeguer
Joaquima
J
San Segundo
Blanca
B
D000818:Animals; D001230:Aspergillus / Q000737:chemistry; D015153:Blotting, Western; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D015870:Gene Expression; D007113:Immunity, Innate / Q000235:genetics; D020082:Magnaporthe / Q000187:drug effects / Q000254:growth & development*; D012275:Oryza / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits
D005656:Fungal Proteins; D010936:Plant Extracts; D010940:Plant Proteins; D012333:RNA, Messenger; C097609:antifungal protein, Aspergillus