Gene edited endophytes

Epichloë endophytes occur naturally in some grasses, such as those used to feed livestock on New Zealand farms. While some types of endophyte can be harmful to livestock, selected endophytes introduced to varieties of grass offer benefits such as deterring insect pests from feeding on the grasses, while minimising any negative health effects.

The addition of selected fungi called Epichloë endophytes to ryegrass has saved New Zealand billions of dollars over the past 30 years, and now gene editing technology could provide even greater benefits through targeted changes to these endophytes. AgResearch scientists, with partners PGG Wrightson Seeds and Grasslanz Technology, supported by funding from the government, have been researching how the use of gene editing tools to change the DNA of endophytes might generate further gains on top of the considerable progress achieved to date by conventional selection.

Over the past few decades scientists and the seed industries have successfully harnessed selected endophytes to add to ryegrass that have brought this billion-dollar benefit, but efforts have continued to identify other endophytes that may further maximise the benefits and minimise the negative effects. AgResearch scientists have now identified targeted changes to the DNA of selected endophytes via gene editing, resulting in either greater plant protection or less harm to livestock. Without intervention, the toxic effect of compounds from some endophytes for livestock is expected to worsen as a result of climate change. The gene editing of organisms is tightly regulated in New Zealand, and to date has only been undertaken in specialised containment facilities. Specific approval is required for field testing in the open or the release of gene edited organisms.