An overview of study on legume plant locoweed endophyte

Locoweed is a common name for the poisonous plants of Astragalus and Oxytropis genera which have swainsonine and cause some livestock clinical disorders, such as locoism. Locoweed has caused enormous economic loss to many countries such as China and USA. Endophytes were firstly discovered and isolated from locoweed in 1999 which was also the first report about endophyte in legume plants and explained the reason about the poison of locoweed. Since then, 15 species of locoweed around the world have been identified as the host of endophyte, including 7 species in Oxytropis genus and 8 species in Astragalus genus. The taxonomy of locoweed endophyte has go through changes which was first identified as Alternaria, and was replaced in Embellisia based on its morphology characters by Braun in 2003 and further was rename as Undifilum- a total new genus in 2009. Until now, there are total 4 species in this genus in which 3 species are locoweed endophytes. Most of the isolated locoweed endophytes have not been identified and named. The studies about biological characteristics of locoweed endophyte, such as distribution, sporulation and transmission are critical reference for controlling the locoism of livestock. This paper reviewed the researches about the habitats, hosts, morphology, physiology and molecular biology of locoweed endophyte, and put forward some highlights that should be paid more attentions in the future researches.