title: Inoculation of cranberry (Vaccinium macrocarpon) with the ericoid mycorrhizal fungus Rhizoscyphus ericae increases nitrate influx.
abstract: Despite the ubiquitous presence of ericoid mycorrhizal (ERM) fungi in cranberry (Vaccinium macrocarpon), no prior studies have examined the effect of ERM colonization on NO(3)(-) influx kinetics. Here, (15)NO(3)(-) influx was measured in nonmycorrhizal and mycorrhizal cranberry in hydroponics. Mycorrhizal cranberry were inoculated with the ERM fungus Rhizoscyphus (syn. Hymenoscyphus) ericae. (15)NO(3)(-) influx by R. ericae in solution culture was also measured. Rhizoscyphus ericae NO(3)(-) influx kinetics were linear when mycelium was exposed for 24 h to 3.8 mm NH(4)(+), and saturable when pretreated with 3.8 mm NO(3)(-), 50 microm NO(3)(-), or 50 microm NH(4)(+). Both low-N pretreatments induced greater NO(3)(-) influx than either of the high-N pretreatments. Nonmycorrhizal cranberry exhibited linear NO(3)(-) influx kinetics. By contrast, mycorrhizal cranberry had saturable NO(3)(-) influx kinetics, with c. eightfold greater NO(3)(-) influx than nonmycorrhizal cranberry at NO(3)(-) concentrations from 20 microm to 2 mm. There was no influence of pretreatments on cranberry NO(3)(-) influx kinetics, regardless of mycorrhizal status. Inoculation with R. ericae increased the capacity of cranberry to utilize NO(3)(-)-N. This finding is significant both for understanding the potential nutrient niche breadth of cranberry and for management of cultivated cranberry when irrigation water sources contain nitrate.
authors.affiliation: Horticulture Department, University of Wisconsin-Madison, 1575 Linden Dr, Madison, WI 53706, USA.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Kosola
authors.affiliation: Horticulture Department, University of Wisconsin-Madison, 1575 Linden Dr, Madison, WI 53706, USA.
authors.forename: Beth Ann A
authors.initials: BAA
authors.lastname: Workmaster
authors.affiliation: Horticulture Department, University of Wisconsin-Madison, 1575 Linden Dr, Madison, WI 53706, USA.
authors.forename: Piero A
authors.initials: PA
authors.lastname: Spada
mesh_terms: D001203:Ascomycota / Q000378:metabolism / Q000502:physiology*; D001692:Biological Transport; D007700:Kinetics; D038821:Mycorrhizae / Q000378:metabolism / Q000502:physiology*; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D029799:Vaccinium macrocarpon / Q000378:metabolism / Q000382:microbiology*