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- Bergman, Anders, et al.
(författare)
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Method to Obtain a Chlorophyll-free Preparation of Intact Mitochondria from Spinach Leaves.
- 1980
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Ingår i: Plant Physiology. - Rockville, USA : AMER SOC PLANT PHYSIOLOGISTS. - 0032-0889 .- 1532-2548. ; 66:3, s. 442-445
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondria from green leaves of spinach have been prepared using a three-step procedure involving differential centrifugation, partition in an aqueous dextran polyethylene glycol two-phase system and Percoll gradient centrifugation. The mitochondrial fractions after the different steps of purification were compared. The final mitochondrial preparation was totally free from chloroplast material measured as chlorophyll content. The enrichment of mitochondria in relation to peroxisomes and microsomes was approximately 12 and 33 times, respectively, based on NAD:isocitrate dehydrogenase activity, glycolate oxidase activity, and NADPH:cytochrome c oxidoreductase activity. The apparent intactness of the inner and the outer mitochondrial membranes was higher than 90% as measured by latency of enzyme activities. The mitochondria showed high respiratory rates with respiratory control and the ADP/O ratios approached the theoretical limits.
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| 2. |
- Esseen, Per-Anders, 1953-
(författare)
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Ecology of lichens in boreal coniferous forests with reference to spatial and temporal patterns
- 1983
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis deals with the ecology of lichens in two contrasting types of forest, epiphytic lichens in old Picea abies forest of the fi re-refugia type and epigeic as well as epixylic lichens in a successional sequence of fire- susceptible Pinus sylvestris forests. Results in five separate papers form the basis for a discussion of general patterns of dispersal, succession and life strategies in lichens. The study sites were located in Medelpad and Västerbotten, in the central and northern part of Sweden, respectively.Special attention has been paid to the rare, pendulous, spruce-1ichen Usnea longissima and the coexisting lichen species. U. longissima is largely restricted to north-facing hill slopes covered with old, mesic spruce forest that is characterized by a very long continuity not disturbed by fire. A marked decline in the number of sites with U. longissima was found. The decline was mainly due to the effect of different forestry practices as the species is very sensitive to environmental disturbances.The epiphytic lichen vegetation of six tree species occurring in the spruce forest is described. Clear successional trends with increasing tree size were • obtained for Alectoria sarmentosa, Bryoria fuscescens coll., B. nadvornikiana, Usnea filipendula' and U. subflorida'na, to a lesser extent for Bryoria capii-“" laris while U. longissima had no relationship to tree size or age.TTstudy of the litterfall of macrofragments of epiphytic lichens showed that thallus fragments were dispersed throughout the year with late autumn, winter and early spring as the most critical periods. It is suggested that dispersal through thallus fragmentation is more important in fruticose than in foliose species and that U. longissima has a shorter range of propagule transport than the other species of Alectoria, Bryoria and Usnea studied. The latter proposition was supported through a study of the horizontal patterns of lichen occurrence in the spruce forest.It is shown that the diversity in ground vegetation, after an initial increase, declines with succession in the pine forests. A mechanism of succession in ground vegetation is presented which suggest that variations in habitat heterogeneity, i.e. the diversity of substrates caused by the initial disturbance and the stand development, largely determines diversity changes during succession. Trends of increasing thallus size, increasing size of asexual reproductive propagules and increased competitive ability with succession formed the basis for recognizing three types of strategies in Cladonia»It is concluded that lichens have features that are compatible with the r-K continuum and that they are variously adapted to both the stability of the substrates and that of the forest as a whole.
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| 3. |
- Gardeström, Per, 1950-, et al.
(författare)
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Oxidation of Glycine via the Respiratory Chain in Mitochondria Prepared from Different Parts of Spinach.
- 1980
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Ingår i: Plant Physiology. - 0032-0889 .- 1532-2548. ; 65:2, s. 389-91
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondria were prepared from roots, stalks, leaves, and leaf veins of spinach. The mitochondrial preparations were examined for their ability to oxidize glycine via the respiratory chain. It is shown that the glycine-oxidizing capacity is restricted to photosynthetically active tissue. The activity is present in mitochondria from the green parts of the leaves, but not in mitochondria from roots, stalks, or leaf veins.
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