Sclerotium rolfsii andSclerotium bataticola could utilize protein and produce extracellular proteinase. In protein-deficient media no extracellular proteinase was detected. In protein-containing media addition of glucose stimulated enzyme synthesis; in absence of glucose addition of ammonium to the protein-media decreased enzyme activity. The rate of protein hydrolysis was higher in media contained glucose but not ammonium. The rate of glucose depletion from the culture filtrates was faster in treatments received protein with glucose or with glucose and ammonium, and addition of sulphur showed slight decrease in glucose utilization.

A salt mixture resistant (SMR) cell line ofVigna radiata (L.) Wilczek was isolated by selection on agar solidified PC-L2 medium supplemented with NaCl, KCl and Na₂SO₄ (8∶1∶1) equimolar to 300 mol m^-3 NaCl, a concentration inhibitory to the wild-type non-selected cells (salt mixture sensitive, SMS). This line retained its resistance after subculture for 3 passages (3 months) on normal medium. The SMR line grew significantly better than SMS line at all the levels of salts, though less in saline medium than the SMR on normal medium. The growth of SMR line was significantly higher than that of SMS line under KCl stress. However, both the lines responded similarly to Na₂SO₄ at a concentration higher than 100 mol m^-3. The SMR line was found to be more sensitive to NaCl than SMS line. The SMR line under salt mixture stress maintained lower levels of Na⁺ and higher levels of K⁺ than SMS line. The SMR line failed to regenerate shoots, although rhizogenesis was observed on PC-L2 medium containing salt mixture (300 mol m^-3).

The effect of shortwave (250 nm) UV radiation (UV-C) on the level of peroxidase activity and peroxidase isoenzyme patterns in leaves of resistant ([Vitis vinifera x Viris riparia] x Vitis rupestris andVitis rupestris) and susceptible (Vitis vinifera) grapevine species toPlasmopara viticola (downy mildew) was studied. The results show that although UV-C did not produce significant changes in peroxidase activity in susceptible species, and only minor changes in resistant species, treatment with UV-light induces an acidic isoperoxidase (isoperoxidase A₁), capable of oxidising 4-hydroxystilbenes in resistant species. It was named HSPrx 2. Since peroxidase is apparently the enzyme responsible for ε-viniferin synthesis from resveratrol in grapevines, a close relationship between this peroxidase isoenzyme and ε-viniferin synthesis which occurs in grapevine leaves after UV-C treatment must be expected.

In the topmost leaves of low-irradiance (LI) tolerant CO 43 and LI susceptible IR 20 rice cultivars, the contents of chlorophyll (chl)a andb and carotenoids and the Hill reaction activity increased under LI. The increase was greater in cv. CO 43 than that in cv. IR 20, and in Chlb than in Chla. The contents of soluble proteins and reducing sugars and nitrate reductase activity of the leaves decreased while the content of non-reducing sugars increased due to shading. The decrease in reducing sugars was greater in cv. CO 43 than in cv. IR 20. On the other hand, the decrease in soluble proteins and nitrate reductase was much less in cv. CO 43 as compared with cv. IR 20.

Biomass, relative growth rate (RGR), organic and inorganic solute contents in control and NaCl (50-100 mM) affected roots or calli of the wild tomato genotypeLycopersicon pennellii and theLycopersicon esculentum wilty mutantflacca were compared. Under NaCl-stress, the RGR of calli fromL. pennellii was higher than that of the mutantflacca, while the root biomass of the former was lower than that of the latter. Constant water contents were found in calli and roots, irrespective of the genotypes and NaCl concentrations. Taking into account the solute contents of the apoplasm, Na⁺ accumulation was similar in the sensitive tissues (calli fromL. flacca, roots ofL. pennellii) and the tolerant ones (calli fromL. pennellii, flacca roots). Decreased K⁺ and Mg²⁺ and increased proline contents were found in both sensitive tissues. In comparison with sensitiveL. pennellii roots, salt sensitiveflacca calli showed increased total organic acid and amino acid contents.

Phosphorylase from tubers ofDioscorea dumentorum was fractionated by (NH₄)₂SO₄ precipitation and further purified to apparent homogeneity. Two forms of phosphorylase, Dd₁ and Dd₂ were obtained with different K_m, optimum temperatures and pH values. They obeyed Michaelis-Menten kinetics, they were activated by AMP, Mg²⁺ and Ca²⁺ but inhibited by ATP, ADP, ADP-glucose and Na₂SO₄. The molecular masses found for Dd₁ and Dd₂ were 102 000 and 195 000 respectively. SDS gel electrophoresis indicated that Dd₂ is a dimer and Dd₁ is a monomer. Both phosphorylase forms contained pyridoxal-5'-phosphate as their prosthetic group, which was essential for their activity. Dd₂ is more active in starch synthesis while Dd₁ is more active in starch degradation. The affinity of the enzyme forms for P_i is not a measure of the rate of glucan degradation. The decline in activities of the enzymes between pH 5.5 and 7.5 was due to unsuitable ionic forms of the enzymes and not due to irreversible denaturation. Both forms of phosphorylase showed double displacement reaction mechanism in direction of phosphorolysis, while in direction of synthesis, sequential mechanism was indicated. Indoleacetic acid activated the enzyme forms in direction of starch degradation but acted as an inhibitor in direction of glucan synthesis. The results of this study suggest that Dd₂ may have some synthetic function while Dd₁ has a degradative role. The effect of pH on the phosphorylase activity suggests histidine as the amino acid residue around the active site that might be involved in enzyme catalysis.

Addition of either abscisic acid (ABA) or kinetin at 10^-6 M to salinized media (20-120mM NaCl) induced remarkable effects on growth ofPhaseolus vulgaris plants. Whereas ABA inhibited the plant growth and the rate of transpiration, kinetin induced stimulation of both parameters. Moreover, ABA increased proline and phosphorus concentrations in the salinized plants whilst kinetin decreased them.
ABA induced stimulation of the transport of K, Ca and Cl from root to shoot, accumulation of K, Na and Cl in root cells and inhibits the transport of Na and accumulation of Ca. Kinetin appeared to inhibit the transport and accumulation of Na and Cl, transport of K, and stimulates the accumulation of K and Ca as well as the transport of Ca. The highest influence of both ABA and kinetin was mostly observed when these hormones were used in combination with the highest concentration of NaCl (120 mM) in the medium.

The germination percentage of chick-pea (Cicer arietinum) Seeds was greatly reduced by temperatures of 30°C and 35°C. This thermoinhibition was overcome by ethylene (ethrel). Both ABA and PEG diminished ethylene production and germination percentage in a parallel way. FC, MGBG and CHA stimulated both ethylene production and germination. AVG reduced ethylene production to some extent but did not inhibit germination. CoCl₂ and PG completely prevented both ethylene production and germination; this effect was reversed by ethylene but not by its immediate precursor ACC. NBE prevented both germination and ethylene production. Our results suggest that high ethylene production rates are not essential for germination of chick-pea seeds but that certain quantities of ethylene may be required.

The effect of four bacterial and six fungal species on nodulation and growth ofVicia faba cv. Giza 3 inoculated withRhizobium leguminosarum biovarviceae strain RCR 1001 were assessed in a pot experiment.Bacillus cereus, Pseudomonas fluorescens, Aspergillus niger andA. quadriliniatus either alive cells or sterile filtrate significantly promoted nodulation, growth and nitrogen accumulation. Heat-killed cells had no effect.

Growth analysis indicated that carbon gain in the alpine succulentSedum album tended to take place early during the growing season. Leaf water potential remained unchanged for a considerable length of time after the imposition of water stress in the field. Induction of crassulacean acid metabolism (CAM) by protracted water stress occurred before any signs of stress could be observed in the leaves, and appeared to be influenced by a complex interaction of environmental conditions including temperature and duration of sunshine. Increased levels of proline and betaine towards the end of the growing season appeared to reflect seasonal changes.

Meristems from 25-90-year-old oak (Quercus robur L. andQ. petraea Matt.) trees and seed embryos were pretreated with polyvinyl pyrrolidone, ascorbic acid, cysteine and citric acid solutions. Tissues were cultured mostly on a WPM medium supplemented with different combinations and concentrations of growth regulators. All the different pretreatments showed a positive effect against the otherwise very rapid and harmful browning of the explants but ascorbic acid (100 mg dm^-3) proved to be the most effective. Shooting was induced from seed embryos and meristems originating from adult trees. Rooted plantlets were obtained from explants of seed embryos.

Water and osmotic potentials were measured in young and mature styles of selfcompatible (SC) and selfincompatible (SI) species ofSolanaceae. For mature flowers, the stylar water and osmotic potentials were considerably lower in SI speciesNicotiana alata andPetunia hybrida than in SC speciesN. sylvestris andN. tabacum. Stylar water content (in % fresh mass) was also significantly lower in SI species (N. alata, P. hybrida, diploid clones of potato) than in SC species (N. acuminata, N. glauca, N. paniculata, N. sylvestris, N. tabacum). For flower buds younger than 2 d before anthesis, no differences in stylar water potential betweenN. alata (SI) andN. tabacum (SC) were observed. During further flower bud development the stylar water potential inN. alata decreased more expressively than inN. tabacum. Pollen culture in media with various concentrations of sucrose or polyethylene glycol revealed that optimal water potential for pollen tube growth was lower inN. alata than inN. tabacum. The differences were similar as for differences in stylar water potential. The results are considered in relation to possible involvement of stylar water potential in unilateral interspecific incompatibility inSolanaceae.

Stem internodes with axillary buds were excised from 5-year old trees ofFicus benjamina cv. Exotica. The effect of 6-benzylaminopurine (BAP), gibberellic acid (GA₃), indole-3-acetic acid (IAA), naphthaleneacetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D) on shoot growth and proliferationin vitro was investigated. Multiple shoots were developed after 3-4 weeks from stem internodes with axillary buds incubated in Murashige and Skoog (MS) medium supplemented with phloroglucinol (PG) and BAP. Optimum shoot proliferation took place in the presence of 1.0 mg l^-1 BAP. Shoots obtained could be elongated in a medium with 0.5 mg l^-1 GA₃ prior to their rooting. The root initiation was successfully induced on MS medium either with IAA at 0.5-0.1 mg l^-1 or in plant growth regulator-free medium. All rooted plantlets were subsequently transferred to a peat, humus and perlite mixture in a culture room with high humidity and covered with plastic bags. After one month the plantlets were established for growing in a greenhouse.

A fully habituated (H) nonorganogenic sugar beet callus, subcultured in the light, did not contain detectable chlorophyll (Chl) nor carotenoid (Car). It accumulated some Car in the dark. Fluorescence spectra indicated that this H callus also accumulated some protochlorophyllide which, however, was not well integrated into the protochlorophyllide-NADPH-photoreductase complex, and therefore not transformed into chlorophyllide in the light. The H callus showed no variable fluorescence which indicated absence of photosynthesis, and therefore it suggested a full heterotrophic behaviour of this peculiar callus line. A green hormone-dependent callus of the same sugar beet had normal fluorescence spectra and kinetics comparable to those of a green leaf.

The embryonic axes of chickpea (Cicer arietinum) seeds were used to quantify 1-(malonyl)aminocyclopropane-1-carboxylic acid (MACC), 1-aminocyclopropane-1-carboxylic acid (ACC), ethylene and some related enzymes during the initial 18 h imbibition period (anaerobic growth phase). Longer cold storage (stratification) of seeds produced higher levels of MACC and ACC. Maximum accumulation of MACC and malonyl-transferase activity occurred after 5 h of growth but MACC levels later became insignificant. ACC-synthase activity and endogenous ACC seem to reach a maximum 2 h after MACC accumulation. MACC-hydrolase activity was measured"in-vitro" and reached a maximum after 5.5 h of growth. These results suggest that endogenous MACC did not seem to be an end product; it may be involved in ACC production and the regulation of ethylene production before the emergence of the radicle. Ethylene-forming enzyme (EFE) activity reached a maximum after 12 h and ethylene production after 18 h of growth. The physiological implications of this temporal separation of MACC, ACC, ethylene and related enzymes is discussed.

A series of binary vector plasmids derived from the T-DNA of theAgrobacterium tumefaciens strain C58, carrying the five plant morphoregulatory genes 1, 2, 4, 5 and 6b in different combinations, was used in the transformation ofNicotiana tabacum leaf discs. Protein patterns of the transgenic tobacco analysed through SDS-PAGE have shown changes in the polypeptides with M_r: ∼120, 60, 55, 43 and 27 kDa (for tobacco with transgene 4); ∼60, 55, 43, 26-25, 21, 18 kDa (for tobacco with transgenes 1, 2 and 5); ∼70, 60, 26, 25, 18 kDa (for tobacco with transgene 5); ∼60, 55, 48, 26, 18 kDa (for tobacco with transgenes 4, 5, 6b); ∼60, 55, 22 and 18 kDa (for tobacco with transgene 6b); ∼60, 55, 43, 26 and 18 kDa (for transgenes 5, 6b); ∼60, 55, 22, 18 and 16 kDa (for transgenes 4 and 6b). All types of transgenic plants showed quantitative changes in protein content. Mendelian segregation ratio to kanamycin resistance in the progeny of transgenic tobacco clones in the R1 generation was 3∶1 except in transgenic tobacco carrying transgenes 1, 2 and 5.

InAlysicarpus vaginalis (L.) DC. nitrogen, ascorbic acid, proline and epicuticular wax (ECW) contents were higher in the plants growing in the coastal region whereas the protein, soluble sugars and starch contents were lower. The higher contents of proline, nitrogen and ascorbic acid recorded in the plants of the saline habitat are a physiological adaptation to overcome the salt stress. The higher ECW content in the plants of the saline habitat specially in the summer months seems to be an adaptation in these plants to survive in the saline habitat.

The water use efficiency (WUE) of the C₃-C₄ intermediate speciesFlaveria anomala andF. pubescens was similar to that found inF. cronquistii (C₃). Compared to this values, the value inF. brownii (C₄-like) was significantly increased and was doubled inF. trinervia (C₄).Moricandia arvensis, a species with an enhanced CO₂ reassimilation potential has a very similar water use efficiency asM. moricandioides (C₃ but a lower transpiration rate.

The development of cleavage polyembryos of wheat, maize and radishin vivo andin vitro was compared. Some frequent features (such as common suspensors or suspensor-like structures, "concrescences", enlarged radicular meristems) suggest a similar origin of cleavage polyembryos inducedin vivo and those inducedin vitro from the proembryo. Cleavage of the original zygotic or somatic proembryo may occur either at a few-celled stage or later in the phase of radicular meristem establishment.

Leaves ofQuercus serrata seedlings were sprayed with solutions of different concentrations of Mg, Zn and Mo-salts and activity of nitrate reductase (NRA) and soluble protein contents were determined in fresh leaves of different ages. The optimum dose for magnesium sulphate and zinc sulphate was 2.5 mM while for ammonium molybdate it was 0.01 mM. Under optimum doses of these nutrients high levels of NRA and protein contents were maintained upto 28 d of spray. Observations on NRA were further confirmed by leaf direct treatment and excised shoot-dipping experiments which showed maximum NRA at comparatively much lower concentrations of ions than those used for spray.