Link to home

Cannot retrieve the URL specified in the Content Link property. For more assistance, contact your site administrator.

Identification of maize WRKY transcription factors responding to Aspergillus flavus infection and their roles in resistance to aflatoxin contamination.
J. FOUNTAIN (1), Y. Raruang (1), M. Luo (1), R. L. Brown (2), Z. Chen (1). (1) Louisiana State University Agricultural Center, Baton Rouge, LA, U.S.A.; (2) USDA-ARS, Southern Regional Research Center, New Orleans, LA, U.S.A.

The colonization of maize (<i>Zea mays</i> L.) by the opportunistic pathogen <i>Aspergillus flavus</i> and subsequent contamination of kernels with its secondary metabolites, aflatoxins, are responsible for significant crop losses and negative impacts to human and animal health. This study focused on the role of maize WRKY transcription factors (WRKY TFs), which form a regulatory network for defense against biotic and abiotic stresses. Previously, seven WRKY TFs significantly regulated by <i>A. flavus</i> infection of maize kernels were identified using oligonucleotide microarray, including <i>Zm</i>WRKY21, <i>Zm</i>WRKY53 (maize and rice homologs), <i>Zm</i>WRKY67, <i>Zm</i>WRKY68, and two putative WRKY TFs. Expression of these WRKY TFs was evaluated from 1 to 18 days after inoculation in maize lines B73 (susceptible) and TZAR-101 (resistant) using quantitative real-time PCR (qPCR). Of particular interest were the homologs of <i>Zm</i>WRKY53. Given the differential expression of <i>Zm</i>WRKY53 homologs observed in this study, the expression of different hormone pathway associated genes were also examined. In addition, H<sub>2</sub>O<sub>2</sub> and lipid peroxidation levels in kernels were also examined for possible correlations with aflatoxin biosynthesis in <i>A. flavus</i>. Analyses of these pathway components may shed light on the resistance mechanisms of maize germplasm in response to <i>A. flavus</i> infection and aflatoxin contamination.<p><p>Keywords: Fungus, Cereals-Grains, Corn

View Presentation