Recently, evidence has increased for both long- and short-distance transport of polyamines (PAs) in living organisms, but the mechanisms involved and physiological significance of PAs translocation are still not well understood. This review deals with various aspects of polyamine uptake and transport in higher plant tissues.

The distribution of xanthoxin (Xan), was determined in light-grown, 20-d-old pea (Pisum sativum L. cv. Progress No. 9) seedlings. The cis,trans-xanthoxin (c,t-Xan) and the trans,trans-xanthoxin (t,t-Xan) were more abundant in the young leaves and terminal bud; their concentrations in leaves were 2 - 3 times those in internodes of the same nodes. After the onset of red-light-irradiation, the concentration of both Xan isomers in 7-d-old dark-grown pea seedlings increased after a 12-h lag time. The increased level of Xan was greatest in the terminal bud and decreased to lower parts of the seedlings. The ratio of c,t-Xan to t,t-Xan concentration in the seedlings was about 2:3.

The effect of light-induced greening of microtubers on their storage behaviour was studied in 16 genotypes of potato. Greening improved the storage of microtubers in terms of shrinkage, biomass loss and sprout emergence. A significant genotype × treatment interaction for shrinkage was observed.

Shoots of the hybrid walnut Juglans nigra x Juglans regia contained serotonin in the micromole range and indole-3-acetic acid (IAA) in the nanomole range. The serotonin level fell by 40 % in 12 h in auxin (IBA) treated whole shoots and then reincreased to a maximum (50 %over the control) after 36 h. The same pattern was followed in the top portions of the shoot but in the shoot bases, serotonin always remained under the control level. The early decrease of serotonin was correlated with an increase in IAA-aspartate. The early decrease and peaking of the serotonin level preceded and corresponded to the increase and peaking of free IAA in the shoot bases. The initial serotonin pool in treated-to-root shoots might thus suffice for the biosynthesis of IAA and IAA-conjugated compounds. Because of its auxin-like properties, the early serotonin peak might be taken into consideration as an endogenous auxin signal for rooting in the present material. If this turns out to be so, the rooting signal for the shoot bases necessarily should come from the apices.

Young rye seedlings (Secale cereale cv. Petkus) were grown for 12 or 18 din aerated nutrient solution. CO2-free air in light or in darkness induced stomatal opening. When light and CO2-free air were applied together, maximum stomatal opening was observed. Na+ channel inhibitor [3H]ouabain was taken up from nutrient medium and translocated into the leaves via the xylem sap. The presence of 10-5 M ouabain in the root medium for 20 h increased stomatal opening and transpiration rate. On the other hand, stomatal closing was not affected by the presence of ouabain. These results suggested that Na+ might play a role in stomatal movements.

Accumulation of the extracellular proteins localized in intercellular spaces of barley primary leaves was examined after inoculation with powdery mildew (Erysiphe graminis f. sp. hordei) as biotic stress factor and after abiotic stresses such as heat shock, low temperature and heavy metal (Mg,Zn, Cu, Al, Cd and Co) treatment using native polyacrylamide gel electrophoresis. Six to eight major pathogen-induced proteins (bands on native gel) have been identified. Their accumulation at host-parasite incompatibility was more expressive than at compatibility interaction. Elevated temperature did not induce pathogenesis-related (PR) proteins while low temperature induced three of them. Cu, Al, Cd and Co induced accumulation pattern of extracellular proteins was very similar to that in powdery mildew inoculated leaves. Mg and Zn had no effect on the induction of protein accumulation in the intercellular spaces of leaves. Induction of PR proteins by different stresses indicated their general function in the resistance of plants to changing environment.

Lupinus albus L. seeds were treated with different concentrations (from 10 µM to 50 mM) of H2O2, m-chloroperoxybenzoic acid (mCPBA), ascorbate (ASC) and glutathione (GSH). The efficiency as inhibitors on germination and on the subsequent growth of the hypocotyl was mCPBA > GSH > ASC = H2O2, which suggest that inhibitory efficiency was dependent on the compound per se rather than on its redox nature.

Accumulation of ABA in shoots during 30-min dehydration of wheat seedlings was accompanied by the decline in the content of zeatin nucleotide and the accumulation of zeatin 9-N-glucoside. The total content of zeatin derivatives as well as the content of free base of zeatin remained almost constant.

Thirty-day-old seedlings of two jute species (Corchorus capsularis L. cv. JRC 212 and C. olitorius L. cv. JRO 632) were subjected to short-term salinity stress (160 and 200 mM NaCl for 1 and 2 d). Relative water content, leaf water potential, water uptake, transpiration rate, water retention, stomatal conductance, net photosynthetic rate and water use efficiency of both jute species decreased due to salinity stress. The decrease was greater in C. olitorius than in C. capsularis and with higher magnitude of stress. Greater accumulation of Na+ and Cl- and a lower ratio of K+/Na+ in the root and shoot of C. olitorius compared with C. capsularis were also recorded. Pretreatment of seedlings with kinetin (0.09 mM), glutamic acid (4 mM) and calcium nitrate (5 mM) for 24 h significantly improved net photosynthesis, transpiration and water use efficiency of salinity stressed plants, the effect being more marked in C. olitorius. Among the pre-treatment chemicals, calcium nitrate was most effective.

An efficient micropropagation protocol was developed for an important medicinal plant, Plantago major L. For this purpose, it is recommended to culture shoot-tips on modified MS medium [412.5 mg dm-3 NH4NO3 and 340 mg dm-3 KH2PO4] supplemented with 50 g dm-3 glucose and 0.5 μM 6-benzylaminopurine. Maximum rooting frequency was obtained at 1 μM naphthaleneacetic acid.

Molecular markers were used to detect the influence of high concentrations of 2,4 dichlorophenoxyacetic acid (2,4-D) in the callusing media on DNA variations in regenerated rice plants. Restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD) and polymerase chain reaction (PCR) based RFLP analysis were carried out on 12 somaclones of Oryza sativa L. cv. B-370. In vitro culture induced DNA variations were detected in the regenerated plants but the effect of high auxin concentration in the medium could not be revealed. In a second study, fingerprinting of 15 semi-dwarf, high yielding somaclones of B-370 was carried out using RAPD technique. Amplification using 20 random primers produced a total of 167 DNA bands out of which 97 bands were polymorphic. A total of 32 unique DNA bands were detected across all the somaclones and they could be grouped based on their similarity to B-370. RAPD analysis helped to reveal similarity or differences among the somaclones while fingerprinting using additional RAPD markers was not successful.

Proline (Pro) accumulation in leaf discs of the NaCl-treated salt sensitive Lycopersicon esculentum was higher than in the salt tolerant L. pennellii. The magnitude of Pro accumulation differed when leaf discs of both species were floated in the light or under darkness, and in various incubation media: buffer solutions (pH from 3.9 to 7.8), abscisic acid, isobutyric acid, NH4Cl, malate, citrate, and mixtures of NaCl and KCl, NaCl and CaCl2, and NaCl and mannitol. Under darkness, Pro accumulation in L. esculentum was not regulated by salts. Conversely, the light-independent NaCl-induced Pro accumulation observed in L. pennellii became light-dependent when CaCl2 was added. The different expression patterns of Pro accumulation reinforce the proposal of two Pro metabolic pathways in the domestic and the wild tomatoes.

Dry matter production of shoots and roots and the diurnal fluctuation of titratable acidity of single leaves were investigated in the CAM plant Agave attenuata during the first 70 d after germination. The plants were grown either in vermiculite sub-irrigated with a nutrient solution or in in vitro cultures on an inorganic nutrient agar. Two types of culture tube covers were used: either airtight closures or polypropylene caps with membranes permeable to air.
In the earliest ontogenetic phases of development (cotyledon and primary leaf stage), the plants were already able to carry out considerable nocturnal organic acid accumulation. In vitro cultivated plants, from the beginning of their development, were also capable of diurnal acid fluctuation, though of distinctly weaker activity than the pot plants. The mean relative growth rates (RGR) of pot culture plantlets approached a third of perennial herbaceous plants. Plantlets grown in in vitro culture reached only half to the one quarter of the RGR of pot plants. The reduced yield could be attributed to the low CO2 supply in the culture tubes and the less than optimal water and nutrient supply in the agar medium.

Pepper species and cultivars, Capsicum annuum cv. Bell Boy, C. annuum cv. Kulai and C. frutescens cv. Padi, differing in drought tolerance were investigated for their water relations, stomatal responses and abscisic acid (ABA) content during water stress. C. frutescens cv. Padi exhibited a greater osmotic adjustment than C. annuum cultivars. Stomatal conductance of cv. Bell Boy was more sensitive to water stress than that of cvs. Kulai and Padi. In all pepper genotypes, stomatal closure was triggered in the absence of a large decrease in leaf water status. ABA content in xylem sap and leaf was higher in C. annum cultivars compared to C. frutescens cv. Padi.

Total genomic DNA isolated from maize hygromycin B resistant cell line(hygr-G204) was used to transform the maize hygromycin B sensitive cell line(hygs-G204) to the hygr-phenotype using polyethyleneglycol treatment and the transformed calli were selected using hygromycin B. The primary transformant maize plants were regenerated and analysed at the molecular level using DNA hybridization, transgenome rescue and histochemical β-glucuronidase assay. The results indicated that genomic DNA-mediated transformation can lead to transfer, expression and stable integration of a DNA fragment into the host genome.

After treatment with increased quantities of nitrogen and Azotobacter strains, activities of antioxidant enzymes superoxide dismutase, peroxidase and catalase, content of chlorophylls and carotenoids, soluble proteins and dry matter in leaves of sugar beet increased.

The first step during shoot primordia development in Papaver somniferum L. was the differentiation of globular meristemoids, resulting from localized cell division in callus tissue. During meristemoid maturation differences observed were in mitotic activity, cytoplasmic density, starch distribution, and in cell size, cell shape, and nucleus size to cell size ratio between peripheral and central meristemoid cells. Cell specialization within the meristemoids is a prerequisite for shoot primordia development.

Growth rate of fruit of Actinidia deliciosa (A. Chev.) Liang and Fergusoncv. Hayward, measured as increase in fresh mass, followed a simple sigmoidal trend showing two stages in all the seasons studied (1987 - 1989). However, growth profiles were statistically different from year to year in both shape and mean reached. The data suggest an important effect of climatic factors on growth, mainly rainfall, which may explain the differences in growth curves between seasons. Significant correlations between relative growth index and length and/or diameter were found which can be used for a non-destructive determination of Actinidia deliciosa fruit growth.

A spermine-resistant mutant of Arabidopsis thaliana (L.) Heynh. was isolated from M2 population of ethylmethanesulphonate-mutagenized seeds. The mutant was resistant to seed germination inhibition by spermine, but was as sensitive as the wild-type to spermidine and putrescine. In addition, the mutant displayed developmental abnormalities such as frequent cauline leaves, increased number of branches with inflorescence, reduced apical dominance, flowers subtended by bracts, disrupted floral organs with homeotic conversions. Genetic analysis indicated a single recessive nuclear mutation that was allelic to apetala2-1 (AP2-1). The new mutant allele of AP2 locus was accordingly numbered as AP2-10.

Zygotic embryos of Karwinskia parvifolia, isolated from seeds obtained from different regions of Mexico, were cultured on Woody Plant Medium (WPM) supplemented with 0.06 µM indole-3-acetic acid, 0.03 µM gibberellic acid, and 2 µM 6-benzylaminopurine. The growth of embryos and multiplication of shoots from stem segments were achieved. Rooting of excised shoots could be initiated on basal WPM medium with prolonged subculture period to 2 months, or on WPM medium supplemented with 10 µM 1-naphthaleneacetic acid. Multiplication capacity of shoots and rooting of K. parvifolia differed in dependence on the origin of explant material. The shoot multiplication was much lower than that of Karwinskia humboldtiana. The rooting depended on the origin of K. parvifolia seeds. The regenerated plants were successfully transferred to glasshouse.

The physiological responses of alfalfa (Medicago sativa L. cv. Gilboa) to salinity (100 mM NaCl) and some inorganic nutrients (K+, Ca2+ and N as NO3-) were investigated. Salinity caused a substantial reduction in biomass, carbon assimilation rate, stomatal conductance, water use efficiency, leaf area, relative growth rate, NO3- content and nitrate reductase activity, whereas, transpiration rate was slightly affected. Inclusion of K+, Ca2+ and N as NO3- in plant nutrient medium in combination or alone brought about a marked stimulation in control plants and moderated the salinity caused reductions in NaCl treated plants. In addition, plants also exhibited differences in these parameters at two growth stages.

The effects of ferulic acid on L-malate oxidation in mitochondria isolated from soybean (Glycine max L.) seedlings were investigated. Oxygen uptake and the products of L-malate oxidation were measured under two conditions: pH 6.8 and 7.8. At acidic pH, the activity of the NAD+-linked malic enzyme (L-malate:NAD+oxidoreductase [decarboxylating] EC 1.1.1.39) was favoured, whereas at alkaline pH a predominance of the L-malate dehydrogenase activity (L-malate:NAD+oxidoreductase EC 1.1.1.37) was apparent. Ferulic acid inhibited basal and coupled respiration during L-malate oxidation either at acidic or alkaline pH, reducing also the amounts of pyruvate or oxaloacetate produced. The results suggest that the site of ferulic acid action is situated at some step that precedes the respiratory chain. An interference with the L-malate entry into the mitochondria could be an explanation for the effects of ferulic acid, but the possibility of a direct inhibition of both enzymes involved in L-malate oxidation cannot be ruled out.