POSTERS: Molecular plant-microbe interactions
A maize line carrying an O-methyl transferase HIGS construct accumulates lower aflatoxin under field conditions
Olanike Omolehin - Department of Plant Pathology and Crop Physiology, Louisiana State Univ AgCenter. Kanniah Rajasekaran- USDA-ARS, SRRC, Qijian Wei- USDA-ARS, SRRC, Yenjit Raruang- Department of Plant Pathology and Crop Physiology, Louisiana State Univ AgCenter, Dongfang Hu- Department of Plant Pathology and Crop Physiology, Louisiana State Univ AgCente
Maize(Zea mays)is one of the most important staple crops and is highly susceptible to both Aspergillus flavusinfection and aflatoxin contamination. Host Induced Gene Silencing (HIGS) has shown promise for plant pathogen management. For this reason, the A. flavusO-methyl transferase (omtA) gene, which encodes a key enzyme involved in aflatoxin biosynthesis, was selected as a target for suppression through HIGS. Positive transformation events containing a portion of the omtA gene in B104 maize zygotic background was first produced in 2013. In 2018, T4 lines from two selected transformation events were planted and self-pollinated. Ears were inoculated with A. flavus14 days after pollination and harvested at maturity for analysis of aflatoxin production. One inoculated homozygous T4omtAevent showed a 3-fold reduction in aflatoxin accumulation compared to the null and B104 inoculated controls (P>0.025). Small RNA sequence analyses of immature maize kernels also revealed the significant difference in sRNA production with high levels of gene specific sRNA being detected in homozygousomtAlines and only background level of sRNA being detected in the null and B104 kernels. The suitabilityof using the omtAgene in HIGS for managing aflatoxin contamination in maize is being evaluated with additional studies.