|Hohn, Thomas - NOVARTIS SEEDS, RTP, NC|
Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 26, 2000
Publication Date: N/A
Interpretive Summary: Some plant disease causing fungi make mycotoxins, small molecules that are toxic both to the plants they infest and to the animals that eat the plants. In order to protect themselves from their own toxins, fungi have developed several strategies, including transporting the toxins outside of their cells and chemically modifying the toxins to make them less potent. We have used the fungal genes that perform these protective functions to endow a model plant with these same protective mechanisms. With either the transporter gene or the mycotoxin modifying gene, the plants were much more resistant to mycotoxins. Given the success of these strategies in this model system, they can now be applied to crop plants such as wheat to help lower the incidence of head scab.
Technical Abstract: Antibiotic-producing organisms protect themselves from these same toxins by metabolic alteration of the compound, modification of the target site of action, or by exporting the compound to the extracellular space. We have tested the effectiveness of adapting two of these strategies, metabolic alteration and extracellular transport, to protect plant cells from the deleterious effects of the trichothecene 4,15-diacetoxyscirpenol (DAS). Tobacco plants were transformed with either the yeast gene PDR5, which encodes a multi-drug transporter, or with the Fusarium sporotrichioides gene TRI101 which encodes a trichothecene 3-O-acetyltransferase. Both genes conferred increased tolerance to DAS as measured by a sensitive seed germination assay. Expression of PDR5 or TRI101 in a seed-specific manner in crop plants such as wheat could lower the incidence of head blight as well as reduce mycotoxin levels within the seed.