Resistance to Aflatoxin Accumulation in Maize Mediated by Host-Induced Silencing of the <i>Aspergillus flavus</i> Alkaline Protease (<i>alk</i>) Gene
<i>Aspergillus flavus</i> is a fungal pathogen that infects maize and produces aflatoxins. Host-Induced Gene Silencing (HIGS) has been shown to reduce host infection by various fungal pathogens. Here, the <i>A. flavus</i> alkaline protease (<i>alk</i>) gene was ta...
Guardado en:
| Autores principales: | , , , , , , , , |
|---|---|
| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
MDPI AG
2021
|
| Materias: | |
| Acceso en línea: | https://doaj.org/article/f3c34a0d00c94124b0e7291fa3af2aed |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| Sumario: | <i>Aspergillus flavus</i> is a fungal pathogen that infects maize and produces aflatoxins. Host-Induced Gene Silencing (HIGS) has been shown to reduce host infection by various fungal pathogens. Here, the <i>A. flavus</i> alkaline protease (<i>alk</i>) gene was targeted for silencing through HIGS. An RNAi vector carrying a portion of the <i>alk</i> gene was incorporated into the B104 maize genome. Four out of eight transformation events containing the <i>alk</i> gene, Alk-3, Alk-4, Alk-7 and Alk-9, were self-pollinated to T4/T6 generations. At T3, the Alk-transgenic lines showed up to 87% reduction in aflatoxin accumulation under laboratory conditions. T4 transgenic Alk-3 and Alk-7 lines, and T5 and T6 Alk-4 and Alk-9 showed an average of 84% reduction in aflatoxin accumulation compared to their null controls under field inoculations (<i>p</i> < 0.05). F<sub>1</sub> hybrids of three elite maize inbred lines and the transgenic lines also showed significant improvement in aflatoxin resistance (<i>p</i> < 0.006 to <i>p</i> < 0.045). Reduced <i>A. flavus</i> growth and levels of fungal <i>ß-tubulin</i> DNA were observed in transgenic kernels during in vitro inoculation. Alk-4 transgenic leaf and immature kernel tissues also contained about 1000-fold higher levels of <i>alk</i>-specific small RNAs compared to null controls, indicating that the enhanced aflatoxin resistance in the transgenic maize kernels is due to suppression of <i>A. flavus</i> infection through HIGS of <i>alk</i> gene. |
|---|