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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food and Feed Safety Research » Research » Research Project #440095

Research Project: Development of Aflatoxin Resistant Corn Lines Using Omic Technologies

Location: Food and Feed Safety Research

2022 Annual Report

1. Gene silencing results in reduction in aflatoxin contamination. Aspergillus (A.) flavus is a mold that infects corn and other susceptible crops and subsequently contaminates them with aflatoxin. Aflatoxins are potent carcinogens that adversely impact human and animal health worldwide.Additionally, contamination of crops with aflatoxin costs tens of millions of dollars annually due to economic losses from the devaluation or destruction of contaminated crops. ARS scientist in New Orleans, Louisiana, had previously shown that an enzyme called alkaline protease is highly expressed by the fungus during the infection of corn kernels. We showed, in collaboration with university scientists, that reducing the level of this fungal enzyme using a technique called host-induced gene silencing, caused an 87% reduction in toxin production in corn. This resistant trait was also transferred to three cultivated corn varieties by hybridization. This work will result in breeding of resistant varieties that can defend themselves against A. flavus.

Review Publications
Castano-Duque, L.M., Gilbert, M.K., Mack, B.M., Lebar, M.D., Carter-Wientjes, C.H., Sickler, C.M., Cary, J.W., Rajasekaran, K. 2021. Flavonoids modulate the accumulation of toxins from Aspergillus flavus in maize kernels. Frontiers in Plant Science. 12:761446.
Omolehin, O., Raruang, Y., Hu, D., Han, Z.-Q., Wei, Q., Wang, K., Rajasekaran, K., Cary, J.W., Chen, Z.-Y. 2021. Resistance to aflatoxin accumulation in maize mediated by host-induced silencing of the Aspergillus flavus alkaline protease (alk) gene. The Journal of Fungi. 7(11):904.
Tao, F., Yao, H., Hruska, Z., Rajasekaran, K., Qin, J., Kim, M.S. 2021. Use of line-scan Raman hyperspectral imaging to identify corn kernels infected with Aspergillus flavus. Journal of Cereal Science. 102:103364.
Tao, F., Yao, H., Hruska, Z., Kincaid, R., Rajasekaran, K. 2022. Near-infrared hyperspectral imaging for evaluation of aflatoxin contamination in corn kernels. Biosystems Engineering. 221:181-194.
Kandel, S.L., Jesmin, R., Mack, B.M., Majumdar, R., Gilbert, M.K., Cary, J.W., Lebar, M.D., Gummadidala, P.M., Calvo, A.M., Rajasekaran, K., Chanda, A. 2022. Vibrio gazogenes inhibits aflatoxin production through downregulation of aflatoxin biosynthetic genes in Aspergillus flavus. PhytoFrontiers. 2(3):218-229.