ARS | Publication request: Confirmation of artificial endophyte inoculation in maize and tomato by scanning electron microscopy and PCR amplification in it sequences

Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: July 28, 2007
Publication Date: N/A

Technical Abstract: Demand for drought tolerant plants is increasing because of water shortages and water quality. Many plant-microbe symbioses have been shown to increase drought resistance in multiple crops with few to no negative effects. Novel, artificially created plant-microbe crosses are being sought to increase drought. All plant species are known to support heavy loads and diverse communities of mutualistic microorganisms on their phylloplane, internal tissues and in the rhizosphere. Carbon expenditures required to support such a heavy load of organisms suggests an undue stress on the host metabolism (Johri 2006) tolerance through combining the benefits from plant breeding with the secondary metabolite production of symbiotic fungi. To initiate novel plant-microbe crosses, plant callus containing fungal endophytes or plugs from pure fungal colonies are placed directly on newly germinated seed radicals. Scanning electron microscopy (SEM) of maize inbred B73 incubated with callus from a Great Basin wild rye (Leymus cinereus) shows appresorium formation and endophyte penetration of host tissue. SEM data from tomato (Solanum lycopersicum) incubations with an endophyte isolated from Fourwing Saltbush (Atriplex canescens) show extensive fungal associations with root hairs. ITS sequence amplification (~600bp fragment) further provides evidence that a novel fungal endophyte has been transferred. Sequence analysis of ITS regions, identification of endophytes, and drought study results are pending.