Turfgrasses as model assay systems for high-throughput in planta screening of beneficial endophytes isolated from cereal crops
Cereal crops including maize (Zea mays L.) are inhabited by non-disease causing microbes known as endophytes that can promote plant growth, aid in host nutrient acquisition and promote host pathogen resistance. Screening endophytes for beneficial traits in planta using large, slow-growing cereals is challenging, thus a rapid but relevant in planta system is needed. Here, we propose that turfgrasses can be used as high-throughput assay systems for screening cereal microbes for beneficial nutrient traits. Turfgrasses are genetic relatives of cereals, but small with fast growth rates; they can be grown in test tubes under sterile conditions on defined media. Five turfgrass genotypes were evaluated for traits ideal for assaying endophytes with nutrient acquisition traits. Based on these criteria, annual ryegrass (Lolium multiflorum) was selected as a high-throughput assay system. Annual ryegrass was then used to test a collection of maize endophytes for their ability to promote plant biomass in the absence of nitrogen. Out of 75 bacterial endophytes tested, one strain (an Enterobacter sp) consistently promoted root and shoot biomass. We discuss the potential of annual ryegrass as a model assay system to test cereal endophytes for acquisition of various nutrients, changes in root/shoot architecture as well as anti-pathogen traits.
KeywordsModel assay system Antifungal Endophytes Cereal crops High-throughput
HRS helped to design the study, carried out all experiments, and wrote the manuscript. EML helped to design the study and provided seed materials. MNR helped to design the study and edited the manuscript. All authors read and approved the final manuscript.
This research was supported by grants to MNR from the Ontario Turfgrass Research Foundation and Growing Forward 2 funds to the Agricultural Adaptation Council (052188 and 052189). HRS was supported by a generous scholarship from the Egyptian Government.
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- Budak H, Shearman RC, Gaussoin RE, Dweikat I (2004) Application of sequence-related amplified polymorphism markers for characterization of turfgrass species. Hortscience 39:955–958Google Scholar
- Johnston-Monje D, Raizada MN (2011b) Integration of biotechnologies - plant and endophyte relationships: nutrient management. In: moo-young M (ed) comprehensive biotechnology, second edition, vol 4. Elsevier, pp 713-727Google Scholar
- Kim S, Lowman S, Hou G, Nowak J, Flinn B, Mei C (2012) Growth promotion and colonization of switchgrass (Panicum virgatum) cv. Alamo by bacterial endophyte Burkholderia phytofirmans strain PsJN. Biotechnol Biofuels 5:37. https://doi.org/10.1186/1754-6834-5-37 CrossRefPubMedPubMedCentralGoogle Scholar
- Li M, G-p S, Wu Y-j, Yu Z-l, Bañuelos G, Yu H-q (2014) Enhancement of nitrogen and phosphorus removal from eutrophic water by economic plant annual ryegrass (Lolium multiflorum) with ion implantation. Environ Sci Pollut Res 21:9617–9625. https://doi.org/10.1007/s11356-014-2987-4 CrossRefGoogle Scholar