Poster: Integrated Plant Biology
Abs #
82: Isolation and Expression of Lai Genes Encoding a-amylase Inhibitor to Control Infection and Aflatoxin Biosynthesis in Maize Kernels
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Presenter: |
Huh, Gyung-Hye , igehuh@inje.ac.kr |
Authors | Huh, Gyung-Hye (A) Kang, Minjung (A) Burt, Bluhm (B) Charles, Woloshuk (B) | | Affiliations: |
(A): Genome Research Center, Inje University
(B): Department of Botany and Plant Pathology, Purdue University
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Aspergillus flavus is a fungal pathogen of maize causing an important ear rot disease when plants are exposed to drought and heat stress. Our previous research has suggested that a-amylase of A. flavus promotes aflatoxin production in the endosperm of infected maize kernels. We also reported that the 36-kDa a-amylase inhibitor purified from Lablab purpureus (AILP) inhibits the a-amylase from a number of fungi but not those from animal and plant sources. Partial peptide sequence of the AILP indicated that AILP is similar to lectin members of a lectin-arcelin-a-amylase inhibitor family described in common bean and shown to be a component of plant resistance to insect pests. The expression of AILP in maize will may result in resistance to A. flavus and reduce aflatoxin contamination in maize. To test this hypothesis, the way of approach is the cloning of the gene encoding AILP and expression of the AILP gene to text a-amylase inhibitor activity.
A fragment of the gene that encoded for 82 residues of AILP amplified with degenerated primers based on peptide sequencing of AILP. Blasting the deduced sequence in database revealed that the peptide is highly homologous to several lectins. Genomic Southern analysis with the PCR product indicates that Lai (Lablab purpureus a-amylase inhibitor) gene is a multigenic family. To get a complete coding region of Lai genes, genomic walker PCR was performed. Herein, we isolated six different Lai genes encoding a-amylase inhibitor. The complete coding region of Lai genes was subcloned into E. coli overexpression vector pET28 and yeast overexpression vector pESC or pPICZ. We will text the a-amylase inhibitor activity of Lai genes.
