Details

Autor(en) / Beteiligte

• Chen, Z.Y
• Brown, R.L
• Rajasekaran, K
• Damann, K.E
• Cleveland, T.E

Titel

Identification of a maize kernel pathogenesis-related protein and evidence for its involvement in resistance to Aspergillus flavus infection and aflatoxin production

Ist Teil von

• Phytopathology, 2006, Vol.96 (1), p.87-95

Ort / Verlag

St. Paul, MN: American Phytopathological Society

Erscheinungsjahr

2006

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• Aflatoxins are carcinogens produced by Aspergillus flavus and A. parasiticus during infection of susceptible crops such as maize. Several aflatoxin-resistant maize genotypes have been identified and kernel proteins have been suggested to play an important role in resistance. In the present study, one protein (#717), which was expressed fivefold higher in three resistant lines compared with three susceptible ones, was identified using proteomics. This protein was sequenced and identified as a pathogenesis-related protein (PR-10) based on its sequence homology. To assess the involvement of this PR-10 protein (ZmPR-10) in host resistance of maize against fungal infection and aflatoxin production, the corresponding cDNA (pr-10) was cloned. It encodes a protein of 160 amino acids with a predicted molecular mass of 16.9 kDa and an isoelectric point of 5.38. The expression of pr-10 during kernel development increased fivefold between 7 and 22 days after pollination, and was induced upon A. flavus infection in the resistant but not in the susceptible genotype. The ZmPR-10 overexpressed in Escherichia coli exhibited a ribonucleolytic and antifungal activities. Leaf extracts of transgenic tobacco plants expressing maize pr-10 also demonstrated RNase activity and inhibited the growth of A. flavus. This evidence suggests that ZmPR-10 plays a role in kernel resistance by inhibiting fungal growth of A. flavus.