Project description:Aflatoxin contamination occurring after infection by Aspergillus flavus is a major concern in maize production both pre- and post-harvest. A recent gene expression study of imbibed kernels highlighted induced resistance and gene regulation in kernels. In the present study, stored mRNA was profiled using oligo-nucleotide array. This comparison of stored mRNAs would enhance our understanding of the difference between resistant and susceptible lines at the kernel storage phase. To minimize the effect of different genetic backgrounds on the differential genes between resistant and susceptible lines, two closely related inbred lines were used. Of the two lines, Eyl25 is aflatoxin-resistant (R), and Eyl31 is –susceptible (S). These were derived from a cross between two resistant lines, 1368 and GT-MASK:gk, in the IITA and USDA- ARS collaborative breeding project.
Project description:Aflatoxin contamination occurring after infection by Aspergillus flavus is a major concern in maize production both pre- and post-harvest. A recent gene expression study of imbibed kernels highlighted induced resistance and gene regulation in kernels. In the present study, stored mRNA was profiled using oligo-nucleotide array. This comparison of stored mRNAs would enhance our understanding of the difference between resistant and susceptible lines at the kernel storage phase. To minimize the effect of different genetic backgrounds on the differential genes between resistant and susceptible lines, two closely related inbred lines were used. Of the two lines, Eyl25 is aflatoxin-resistant (R), and Eyl31 is –susceptible (S). These were derived from a cross between two resistant lines, 1368 and GT-MASK:gk, in the IITA and USDA- ARS collaborative breeding project. Direct comparisons were designed between Eyl25 and Eyl31. Dry kernels from the two lines were selected randomly into four groups to extract total RNA. Four biological replications were performed in the comparison including two dye-swaps.
Project description:Transcriptomic profiles revealed that the common and unique different expression genes were identified in lateral leaflet and terminal leaflet, using petiole as a control.What's more, transcriptomic analysis was performed to compare the difference of a natural mutant with pentafoliate defects and wild type.
Project description:Aspergillus flavus contaminates crops during preharvest and post-harvest periods and produce carcinogenic mycotoxin aflatoxins posing severe threat to food safety and human health. To identify potential targets to tackle aflatoxin contamination, we have characterized a novel Afper1, sharing sequence identity with the yeast protein per1, regulating cell development and secondary metabolism in A. flavus. Notably, proteomics analysis revealed that the enzymes involved in extracellular hydrolases, conidial development, ER homeostasis, and aflatoxin biosynthesis significantly varied. Unexpectedly, enzymes participated in scavenging ROS including catA, catB, cpeB, and sodM were significantly downregulated and the accumulated ROS and sensitivity to hydrogen peroxide were confirmed by experiments. Surprisingly, Afper1 deletion significantly unregulated heterochromatin protein (HepA) and downregulated GNAT family acetyltransferase involved in heterochromatin formation. Accompanying the accumulated ROS and chromatin remodelling, enzymes participating in aflatoxins, ustiloxin B, and gliotoxin were impaired. These results implied that Afper1 affected chromatin remodelling and disturbed ER homeostasis leading to the accumulation of ROS, and ultimately resulted in growth defect and impaired secondary metabolites biosynthesis.
