Expression Profiling Coupled with In-silico Mapping Identifies Candidate Genes for Reducing Aflatoxin Accumulation in
Ramesh Dhakal1, Chenglin Chai1, Ratna Karan2
1School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural CenterBaton Rouge, LA, USA.
Frontiers in Plant Science
|April 22, 2017
Summary
Identifying genes for maize resistance to aflatoxin accumulation is crucial for livestock and human health. This study found key differentially expressed genes in resistant maize inbreds, offering targets for improving crop safety.
Area of Science:
- Plant Pathology
- Genetics
- Molecular Biology
Background:
- Aflatoxin contamination in maize poses significant health risks to humans and livestock.
- Limited knowledge of quantitative trait loci (QTL) for aflatoxin resistance hinders marker-assisted selection in maize breeding.
- Understanding host resistance mechanisms is vital for developing maize varieties with improved resistance to Aspergillus flavus infection.
Purpose of the Study:
- To identify differentially expressed genes (DEGs) in maize kernels resistant to aflatoxin accumulation.
- To map these DEGs to the corn genome and identify candidate genes within known QTL regions.
- To provide insights into the genetic basis of maize resistance to Aspergillus flavus.
Main Methods:
- Suppression subtraction hybridization (SSH) cDNA library construction from resistant (Mp715) and susceptible (B73) maize inbreds.
- Sequencing of cDNA clones, in-silico mapping, and identification of unigenes and DEGs.
- Reverse northern and quantitative RT-PCR analyses to validate gene expression in maize inbreds with varying aflatoxin resistance.
Main Results:
- 267 unigenes identified, with most related to metabolism, stress response, and disease resistance.
- 26 DEGs selected, with most showing higher expression in resistant maize inbreds post-Aspergillus flavus inoculation.
- Upregulation of PR-4, DEAD-box RNA helicase, and leucine-rich repeat family protein validated in resistant inbreds.
- 56 unigenes mapped to QTL regions associated with aflatoxin resistance.
Conclusions:
- Identified candidate genes related to disease resistance, stress response, and metabolism are crucial for understanding host-pathogen interactions.
- These candidate genes offer potential targets for genetic improvement of maize to reduce aflatoxin accumulation.
- The findings facilitate marker-assisted selection strategies for developing safer maize varieties.
