Defining the molecular impacts of Humalite application on field-grown wheat (Triticum aestivum L.) using quantitative proteomics

Increasing global food production demands have resulted in increased fertilizer usage, causing detrimental environmental impacts. Biostimulants, such as humic substances, are currently being applied as a strategy to increase plant nutrient-use efficiency and minimize environmental impacts within cropping systems. Humalite is a unique, naturally occurring coal-like substance found in deposits across southern Alberta. These deposits contain exceptionally high ratios of humic acids (>70%) and micronutrients due to their unique freshwater depositional environment. Humalite has begun to be applied to fields by local growers in Alberta, despite limited scientific data on yield impacts across diverse crops. Recent work has shown positive impacts on plant growth, yield and nutrient usage in wheat plants supplemented with Humalite; however, there is little known of the impact of Humalite at the molecular level. Here, we report a quantitative proteomics approach to identify systems-level molecular changes induced by the addition of different Humalite application rates in field-grown wheat (Triticum aestivum L.) under three urea fertilizer application rates. In particular, we see wide-ranging protein abundance changes in proteins associated with several metabolic pathways and growth-related biological processes that suggest how Humalite modulates the plant molecular landscape. Our results provide new, functional information that will help better inform agricultural producers on optimal biostimulant and fertilizer usage.