Understanding the contribution of the inherited microbiome to corn yield and immunity-suppressing vomitoxin

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Corn farming in the 20th-Century was transformed by the discovery of hybrid vigour, the mysterious phenomenon wherein mating of two genetically-diverse inbreds causes dramatic yield boosts. This led to seed companies that employ Canadians. The potential of hybrid vigour has yet to be fully realized in corn, soy, wheat, other crops & livestock, because the underlying biological basis is incompletely understood --it remains the Holy Grail of genetics. One theory never before explored is that hybrid vigour may be partially caused by variation in the plant microbiome. We hypothesize that microbiomes may be variably inherited from parents through pollen/eggs into (hybrid) seeds. Thus, when two parents mate, two distinct/competing microbiomes are meeting each other for the first time (in seed), causing gain/loss of good bacteria. We propose to mate diverse inbreds together, profile offspring microbiomes, then correlate microbial inheritance with yield & Fusarium disease resistance. Fusarium caused 40% yield losses to corn in Ontario in 2018, due to its production of DON mycotoxin (vomitoxin), devastating farmer profits. Vomitoxin is heat-stable to 350C & shown to enter the food chain (e.g. kid's cereal) & hence it is regulated in Canada. Preventing vomitoxin from reaching vulnerable people may be critical in this era, because it suppresses human/animal immunity, reduces viral immunity, exacerbates viral bronchopneumonia & reduces vaccine effectiveness in animal models. With our partner, Grain Farmers of Ontario (GFO), short-term, we hope to identify one heritable microbial consortium that protects Canadian (Cdn) corn: increases grain yield by >5% & decreases vomitoxin by >10%. We also propose to contribute to a vomitoxin susceptibility diagnostic for new corn hybrids based on the presence/absence of anti-Fusarium microbes. This will improve Cdn corn exports & improve farmer profits by $100 million at this uncertain time, while ensuring safer supplies of grain for livestock, Cdn consumers & poor nations lacking fungicides. Long-term, this research could catalyze novel crop breeding, wherein breeders directly select for stable inheritance of good bacteria using microbial markers, leading to the next great leap in agriculture.