ISSN:
1573-5036
Keywords:
actinorhizae
;
Alnus
;
Frankia
;
nitrogen-fixation
;
xerotolerance
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract The osmotolerance, rather than the halotolerance, of the endosymbiont predicted the xerotolerance of acetylene reduction by Alnus nodulated withFrankia ARgP5 AG . Cloned plants ofAlnus glutinosa (L.) Gaertn. AG8022-16 were subjected to water stress under controlled conditions in an environmental growth chamber. Transpiration, stomatal conductance, and leaf water potential had decreased after successive 10 day periods of moderate (75% of water demand) and severe (50% of water demand) water stress. After severe stress had wilted the plants, reducing leaf water potential to −2.10 MPa, nitrogenase activity had fallen to 2.51 μM per plant per hour. The reported rapid turnover of nitrogenase implies thatFrankia mycelium was metabolically active at this low water potential, a water potential at which no Alnus-derivedFrankia has been reported active. Although ARgP5 AG was similar to other such strains in halotolerance (lower limitca.−1.25 MPa), the low water potential limit for growth with glucose (a non-assimilated osmoticum) wasca.−2.53 MPa. Nitrogenase activity was apparently more limited by host xerotolerance than by endophyte xerotolerance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02232793
Permalink
