International Journal of Agricultural Sciences

International Journal of Agricultural Sciences ISSN 2167-0447 Vol. 11 (1), pp. 001-008, January, 2021. © International Scholars Journals

Full Length Research Paper

Evaluation of the effects of drought stressed conditions on gene expression in various maize genotypes

Jake C. Fountain1,2,3, Zhi-Yuan Chen3, Brian T. Scully1, Robert C. Kemerait4, R. Dewey Lee5, Baozhu Guo1*

1USDA-ARS, Crop Protection and Management Research Unit, 2747 Davis Rd., Tifton, GA, 31793, USA.

2Department of Biology, Georgia Southwestern State University, 800 GSW University Dr., Americus, GA, 31709, USA.

3Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, 302 Life Science Building, Baton Rouge, LA, 70803, USA.

4Department of Plant Pathology, University of Georgia, Tifton Campus, 4604 Research Way, Tifton, GA, 31793, USA.

5Department of Crop and Soil Sciences, University of Georgia, Tifton Campus, 4604 Research Way, Tifton, GA, 31793, USA.

Accepted 16 October, 2020


Aflatoxins are carcinogenic compounds produced by Aspergillus flavus during infection of crops including maize (Zea mays L.). Contamination of maize with aflatoxin is exacerbated by late season drought stress. Previous studies have implicated numerous resistance-associated proteins (RAPs) that may be responsible for resistance to A. flavus colonization and aflatoxin accumulation. This study examined the transcript levels of three genes encoding RAPs utilizing quantitative real-time PCR, ZmPR -10 (PR-10), glyoxalase I (GLX-I), and a 14-kDa trypsin inhibitor (TI-14), in different maize lines under drought stressed and irrigated conditions to determine their potential utility as molecular markers for germplasm. Results suggested that drought stress during kernel development affected gene expression differently in different genotypes. Results showed that physiological stress induced by drought conditions was insufficient to stimulate significant changes in the expression of genes coding for the pathogen-specific, pathogenesis-related proteins PR-10 and GLX-I. However, ti-14 transcript levels were found to be elevated significantly indicating its possible use as a selection marker.

Key words: Zea mays, anti-fungal protein, aflatoxin, drought stress, qPCR.