Abstract
Fungal pathogens are seriously threatening food security and natural ecosystems; efficient and environmentally friendly control methods are essential to help safeguard such resources for increasing human populations on a global scale. Here, we find that Sclerotinia sclerotiorum, a widespread pathogen of dicotyledons, can grow endophytically in wheat, rice, barley, maize, and oat, providing protection against Fusarium head blight, stripe rust, and rice blast. Protection is also provided by disabled S. sclerotiorum strains harboring a hypovirulence virus. The disabled strain DT-8 promoted wheat yields by 4–18% in the field and consistently reduced Fusarium disease by 40–60% across multiple field trials. We term the host-dependent trophism of S. sclerotiorum, destructively pathogenic or mutualistically endophytic, as schizotrophism. As a biotroph, S. sclerotiorum modified the expression of wheat genes involved in disease resistance and photosynthesis and increased the level of IAA. Our study shows that a broad-spectrum pathogen of one group of plants may be employed as a biocontrol agent in a different group of plants where they can be utilized as beneficial microorganisms while avoiding the risk of in-field release of pathogens. Our study also raises provocative questions about the potential role of schizotrophic endophytes in natural ecosystems.
Highlights
IntroductionMore than 80% of crop diseases are caused by fungi or fungus-like pathogens that threaten food security
Supplementary information The online version of this article contains supplementary material, which is available to authorized users.More than 80% of crop diseases are caused by fungi or fungus-like pathogens that threaten food security
The growth of S. sclerotiorum in wheat roots was confirmed by transmission electron microscopy (TEM) using an immunogold labeling technique with an antibody against the mCherry protein, the latter observed to be randomly distributed in the fungal cells (Fig. 1b1–b3)
Summary
More than 80% of crop diseases are caused by fungi or fungus-like pathogens that threaten food security. Many fungal pathogens produce mycotoxins, such as ergotamine, deoxynivalenol (DON), and aflatoxin that further threaten human and livestock health [2, 3]. Cereal crops provide a major food source for human beings and animals. They are heavily attacked by fungal pathogens, such as the rice blast fungus Magnaporthe oryzae, wheat rust fungi Puccinia spp, and the wheat head blight fungus Fusarium graminearum [4]. Strain Ug99 of the wheat stem rust fungus [6] and the recently emerged wheat blast fungus [7] threaten wheat crops that support ~20% of human food consumption [8].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
