Plant regeneration from protoplasts of Capsicum annuum L cv. California Wonder

Plant regeneration from mesophyll protoplasts of pepper, Capsicum annuum L. cv. California Wonder has been demonstrated via shoot organogenesis, Protoplasts isolated from fully expanded leaves of 3-week-old axenic shoots when cultured in TM medium supplemented with 1 mgl(-1) NAA, 1 mgl(-1) 2, 4-D, 0.5 mgl(-1) BAP (CM 1) resulted in divisions with a frequency ranging from 20-25%. Antioxidant ascorbic acid and polyvinylpyrrolidone (PVP) in the medium and incubation in the dark helped overcome browning of protoplasts. Microcalli and macrocalli were formed in TM medium containing 2 mgl(-1) NAA and 0.5 mgl(-1) BAP (CM II) and MS gelled medium containing 2 mgl(-1) NAA and 0.5 mgl(-1) BAP (CM III), respectively, Regeneration of plantlets was possible via caulogenesis, Microshoots, 2-5 per callus appeared on MS gelled medium enriched with 0.5 mgl(-1) IAA, 2 mgl(-1) GA and 10 mgl(-1) BAP (CM IVc). Rooting of microshoots was obtained on half strength gelled medium containing 1 mgl(-1) NAA and 0.5 mgl(-1) BAP, Protoplasts isolated from cotyledons failed to divide and degenerated eventually.

X-ray studies on crystalline complexes involving amino acids and peptides. XXIII. Variability in ionization state, conformation and molecular aggregation in the complexes of succinic acid with DL- and L-lysine

Crystalline complexes of succinic acid with DL- and L-lysine have been prepared and analysed by X-ray diffraction. DL-Lysine complex: C6HIsN202 + 1 2- 1 ~C4H404 .~C4H604, Mr -- 264"2, PI, a = 5"506 (4), =8.070(2), c=14.089(2) A,, a=92.02(1), /3= 100"69 (3), y = 95"85 (3) ~>, Z = 2, Dx = 1"44 g cm -3, R = 0.059 for 2546 observed reflections. Form I of the e-lysine complex: C6HIsN20-, ~ .C4H504, Mr = 264.2, P1, a = 5" 125 (2), b = 8"087 (1), c = 8"689 (1) A,, a = 112.06 (1), /3 = 99.08 (2), y = 93"77(2) °, Z--l, D,,,=1"34(3), Dx=l"34gcm 3 R = 0.033 for 1475 observed reflections. Form II of + I 2- the e-lysine complex: C6H15N202 .,iC4H404 .- 1 I ") 4C4H604.4(C4HsO4""H'"CaH404)" , Mr = 264"2, P1, a = 10.143 (4), b = 10.256 (2), c = 12"916 (3) A,, a = 105.00 (2),/3 = 99-09 (3), y = 92"78 (3)::, Z = 4, Dm= 1"37(4), D,.= 1.38gcm 3, R=0.067 for 2809 observed reflections. The succinic acid molecules in the structures exhibit a variety of ionization states. Two of the lysine conformations found in the complexes have been observed for the first time in crystals containing lysine. Form II of the L-lysine complex is highly pseudosymmetric. In all the complexes, unlike molecules aggregate into separate alternating layers. The basic element of aggregation in the lysine layer in the complexes is an S2-type head-to-tail sequence. This element combines in different ways in the three structures. The basic element of aggre gation in the succinic acid layer in the complexes is a hydrogen-bonded ribbon. The ribbons are interconnected indirectly through amino groups in the lysine layer.

Characterization of Somatic Embryogenesis in Sandalwood (Santalum album L.)

In the synchronous embryogenesis system of sandalwood developed in our laboratory, we observed that the early events of differentiation from freshly induced callus (stage 0) are accomplished in three distinct stages viz., preglobular masses (stage 1), globular embryos (stage 2), and bipolar embryos (stage 3). Transition from stage 0 to 1 was accomplished using 2,4-D and involves a stage specific appearance of two polypeptides of 15 and 30 kDa molecular weight. A 24 kDa polypeptide that was detected as a marked band in extracts of primary callus was not detected in stages 1, 2, and 3. Further, the tissue level of a 50 kDa glycoprotein decreased during transition from stage 2 to stage 3. However, the levels of glycoproteins in the medium were markedly higher in stage 0 cultures compared to those in stage 1. The activities of a protein kinase, glycosidase, and xylanase increased markedly with progressing embryogenesis. Our observations suggest that in addition to being controlled at the level of stage-specific gene expression, somatic embryogenesis in sandalwood is also regulated at the level of controls on cell wall flexibility and posttranslational changes in the pool of preexisting proteins.

The ecology of the mountain hare (Lepus timidus L.) in managed boreal forests: habitat associations at different forest scales

Aims of this thesis This study is part of a larger hare project in Finland, which provides answers to basic ecological questions regarding the mountain hare. This study of the ecology of the mountain hare focuses in particular on different levels of managed boreal forest. The feeding habits and intensity of mountain hares in winter are explored, and the connections between mountain hares versus the forest structure are also studied (e.g. habitat use and the importance of different forest layers for hares). The use of the environment by hares at the landscape level was examined (forest patch structures), and the home ranges of mountain hares were studied. Finally, the productivity and survival rate of mountain hare populations were also studied (discussion e.g. predator effects on hare populations). Conclusions Feeding intensity seemed to be highest in the spring-winter, when home ranges were also largest. Favourable food species are covered by snow in winter and the mobility of hares is highest during late winter. A shortage of suitable food species may be problematic for hares, especially during the winter period. In this study mountain hares preferred a dense shrub layer at local level and deciduous and mixed tree forest over coniferous forest at the landscape level. Food and shelter are vital for hares and the preference for particular habitats may also affect the population dynamics of the mountain hare. It would be possible to improve the quality of food and shelter or at least prevent the most negative habitat changes through forest management. At a local level it is also possible to add supplementary food for hares through the winter period. The intensive clearing of young sapling stands and especially the removal of deciduous shrubs and trees reduces the quality of habitats for the mountain hare. Mountain hares primarily live in forest habitat and it is possible that changes in the forest structure play a crucial role in mountain hare habitat preference. Ecological knowledge of the mountain hare is vital to create habitat structure more suitable for the species. More deciduous trees should be saved in managing forests and the mechanical clearing of the shrub layer should be done carefully.

Purification and properties of protocatechuate-3,4-dioxygenase from Tecoma stans L

Protocatechuate-3,4-dioxygenase from the leaves of Tecoma stans was purified to near homogeneity and some of its properties studied. It was optimally active at pH 5.2 and at 40°C. Its molecular weight of approx. 150 000 was determined by gel filtration on a Sephadex G-150 column. The Km value for protocatechuate was found to be 330 μM and for ferrous sulfate, 40 μM. The enzyme was highly specific for protocatechuate and did not attack any of the substrate analogues. None of the substrate analogues tested inhibited the enzyme activity. Sulfhydryl reagents inhibited the enzyme activity which could be partially reversed by sulfhydryl compounds. The dioxygenase activity was not associated with polyphenol oxidase activity.

Effects of large-scale human land use on Capercaillie (Tetrao urogallus L.) populations in Finland

The Capercaillie (Tetrao urogallus L.) is often used as a focal species for landscape ecological studies: the minimum size for its lekking area is 300 ha, and the annual home range for an individual may cover 30 80 km2. In Finland, Capercaillie populations have decreased by approximately 40 85%, with the declines likely to have started in the 1940s. Although the declines have partly stabilized from the 1990s onwards, it is obvious that the negative population trend was at least partly caused by changes in human land use. The aim of this thesis was to study the connections between human land use and Capercaillie populations in Finland, using several spatial and temporal scales. First, the effect of forest age structure on Capercaillie population trends was studied in 18 forestry board districts in Finland, during 1965 1988. Second, the abundances of Capercaillie and Moose (Alces alces L.) were compared in terms of several land-use variables on a scale of 50 × 50 km grids and in five regions in Finland. Third, the effects of forest cover and fine-grain forest fragmentation on Capercaillie lekking area persistence were studied in three study locations in Finland, on 1000 and 3000 m spatial scales surrounding the leks. The analyses considering lekking areas were performed with two definitions for forest: > 60 and > 152 m3ha 1 of timber volume. The results show that patterns and processes at large spatial scales strongly influence Capercaillie in Finland. In particular, in southwestern and eastern Finland, high forest cover and low human impact were found to be beneficial for this species. Forest cover (> 60 m3ha 1 of timber) surrounding the lekking sites positively affected lekking area persistence only at the larger landscape scale (3000 m radius). The effects of older forest classes were hard to assess due to scarcity of older forests in several study areas. Young and middle-aged forest classes were common in the vicinity of areas with high Capercaillie abundances especially in northern Finland. The increase in the amount of younger forest classes did not provide a good explanation for Capercaillie population decline in 1965 1988. In addition, there was no significant connection between mature forests (> 152 m3ha 1 of timber) and lekking area persistence in Finland. It seems that in present-day Finnish landscapes, area covered with old forest is either too scarce to efficiently explain the abundance of Capercaillie and the persistence of the lekking areas, or the effect of forest age is only important when considering smaller spatial scales than the ones studied in this thesis. In conclusion, larger spatial scales should be considered for assessing the future Capercaillie management. According to the proposed multi-level planning, the first priority should be to secure the large, regional-scale forest cover, and the second priority should be to maintain fine-grained, heterogeneous structure within the separate forest patches. A management unit covering hundreds of hectares, or even tens or hundreds of square kilometers, should be covered, which requires regional-level land-use planning and co-operation between forest owners.

The crystal and molecular structure of benzyloxycarbonyl-a-amino-isobutyryl-L-prolyl-methylamide. The observation of an X2-Pro3 Type III b-turn

The crystal and molecular structure of N-benzyloxycarbonyl-a-aminoisobutyryl-L-prolyl methylamide, the amino terminal dipeptide fragment of alamethicin, has been determined using direct methods. The compound crystallizes in the orthorhombic system with the space group P212-21. Cell dimensions are a = 7.705 A, b = 11.365 A, and c = 21.904 A. The structure has been refined using conventional procedures to a final R factor of 0.054. The molecular structure possesses a 4 - 1 intramolecular N-H--0 hydrogen bond formed between the CO group of the urethane moiety and the NH group of the methylamide function. The peptide backbone adopts the type 111 P-turn conformation, with 42 = -51.0°, +* = -39.7",&j = -65.0', $3 = -25.4'. An unusual feature is the occurrence of the proline residue at position 3 of the P-turn. The observed structure supports the view that Aib residues initiate the formation of type 111 @-turn conformations. The pyrrolidine ring is puckered in Cy-exo fashion.

Type II beta-turn conformation of pivaloyl-L-prolyl-a-aminoiso-butyryl-N-methylamide: Theoretical, spectroscopic and X-ray studies

Pivaloyl-L-Pro-Aib-N-methylamihdaes been shown to possess one intramolecular hydrogen bond in (CD&SO solution, by 'H-nmr methods, suggesting the existence of p-turns, with Pro-Aib as the corner residues. Theoretical conformational analysis suggests that Type II P-turn conformations are about 2 kcal mol-' more stable than Type 111 structures. A crystallographic study has established the Type I1 /%turn in the solid state. The molecule crystallizes in the space group P21 with a = 5.865 8, b = 11.421 A, c = 12.966 A, /3 = 97.55", and 2 = 2. The structure has been refined to a final R value of 0.061. The Type I1 p-turn conformation is stabilized by an intramolecular 4 - 1 hydrogen bond between the methylamide NH and the pivaloyl CO group. The conformational angles are @pro= -57.8", $pro = 139.3', @Aib = 61.4', and $Ajb = 25.1'. The Type 11 /%turn conformation for Pro-Aib in this peptide is compared with the Type I11 structures observed for the same segment in larger peptides.