Role of Amino Acids in Plant Responses to Stresses

V.K. Rai

Biologia plantarum 2002, 45:481-487 | DOI: 10.1023/A:1022308229759

Plants subjected to stress show accumulation of proline and other amino acids. The role played by accumulated amino acids in plants varies from acting as osmolyte, regulation of ion transport, modulating stomatal opening, and detoxification of heavy metals. Amino acids also affect synthesis and activity of some enzymes, gene expression, and redox-homeostasis. These roles played by amino acids have been critically examined and reviewed.

Schekman, R., Goldstein, L., McKnight, S.L., Rossant, J. (ed.): Annual Review of Cell and Developmental Biology. Vol. 17

T. Gichner

Biologia plantarum 2002, 45:488 | DOI: 10.1023/A:1022301925409

Propagation of Chelidonium majus L. by Somatic Embryogenesis

B. Vinterhalter, D. Vinterhalter

Biologia plantarum 2002, 45:489-493 | DOI: 10.1023/A:1022360230668

Direct somatic embryogenesis in celandine (Chelidonium majus L.) was achieved in epicotyl explants of seedlings after prolonged cultivation on Murashige and Skoog medium with or without plant growth regulators. Somatic embryos developed into plantlets which entered additional cycles of somatic embryogenesis. Cultures consisting of plantlets with prolonged embryogenic potential were maintained for five years on plant growth regulator free medium. Embryos which developed into rooted plantlets could be acclimated in a glasshouse enabling thus a continuous propagation scheme to be established.

Karnosky, D.F., Ceulemans, R., Scarascia-Mugnozza, G.E., Innes, J.L. (ed.): The Impact of Carbon Dioxide and Other Greenhouse Gases on Forest Ecosystems

J. Pospíšilová

Biologia plantarum 2002, 45:494 | DOI: 10.1023/A:1022353931769

Effect of Callus Induction Media on Morphology of Embryogenic Calli in Rice Genotypes

K.B.R.S. Visarada, M. Sailaja, N.P. Sarma

Biologia plantarum 2002, 45:495-502 | DOI: 10.1023/A:1022323221513

Effects of four culture media on callus induction, regeneration and number of plants per unit culture were studied with mature seeds from five indica rice genotypes as explants. Based on the morphology, the calli were classified into four types as I to IV. Type I and type II are most suited to initiate suspension cultures or as target material for transformation. Number of plants regenerated per unit culture, formation of easily dissociating cell clusters and frequency of type I and type II calli were highest on NBKNB medium. Thus NBKNB medium is suitable for in vitro culture of even the hitherto recalcitrant indica genotypes.

High Frequency Multiple Shoot Regeneration from Decapitated Embryo Axes of Chickpea and Establishment of Plantlets in the Open Environment

R. Singh, K. Srivastava, H.K. Jaiswal, D.V. Amla, B.D. Singh

Biologia plantarum 2002, 45:503-508 | DOI: 10.1023/A:1022308605583

Multiple shoot regeneration from the cut plumular ends of embryo axes of chickpea (Cicer arietinum L.) was evaluated on Murashige and Skoog medium having different concentrations of thidiazuron (TDZ) (0.1 to 10.0 mg dm^-3) 6-benzylaminopurine (BAP) (0.5 and 1.0 mg dm^-3), kinetin (0.5 and 1.0 mg dm^-3) or zeatin (2.0 and 4.0 mg dm^-3). TDZ (0.2 mg dm^-3) was found to be the most effective cytokinin as it produced multiple shoots in 100 % of the explants from genotypes C235, ICC5166, ICC12269, ICC4951, ICC11531, BG256 and a local cultivar. Shoots were elongated on growth regulator-free medium,...

Induced DNA Damage Measured by the Comet Assay in 10 Weed Species

T. Gichner, Z. Mühlfeldová

Biologia plantarum 2002, 45:509-516 | DOI: 10.1023/A:1022360722422

For most plant species growing in polluted areas no mutagenicity assays are available. We have studied the possibility of using the alkaline protocol of the Comet assay as a method for detecting induced DNA damage in wildly growing weeds. The monofuctional alkylating agent ethyl methanesulphonate (EMS) was applied on leaves of 10 weed species (ordered according to the diameter of the nuclei): Arabidopsis thaliana, Convolvulus arvensis, Bellis perennis, Urtica dioica, Lamium album, Chenopodium rubrum, Plantago media, Poa annua, Taraxacum officinale, and Agropyron repens. With increasing concentrations of EMS (2 to 10 mM) the DNA damage,...

Malate Dehydrogenase, Alcohol Dehydrogenase, and 6-Phosphogluconate Dehydrogenase Isozymes of Zea mays L. × Tripsacum dactyloides L. Hybrids and Parents

V. Tsanev, R. Vladova, K. Petkolicheva, B. Kraptchev, C. Milanov

Biologia plantarum 2002, 45:517-522 | DOI: 10.1023/A:1022312806492

Electrophoretic patterns of malate dehydrogenase (Mdh), alcohol dehydrogenase (Adh), and 6-phosphogluconate dehydrogenase (Pgd) of Zea mays L. × Tripsacum dactyloides L. hybrids and their parents were compared. The components of enzymes specific to T. dactyloides may be used as markers to identify the following T. dactyloides chromosomes in the hybrids: Tr 16 (Mdh 2 and Pdg 1), Tr 7, and/or Tr 13 (Adh 2). The isozymes of Mdh 2 are supposed as a possible biochemical marker to evaluate the introgression of genes, determining an apomictic mode of reproduction from T. dactyloides (localized on Tripsacum 16 chromosome)...

RAPD Profile Analysis of Betel Vine Cultivars

S.A. Ranade, A. Verma, M. Gupta, N. Kumar

Biologia plantarum 2002, 45:523-527 | DOI: 10.1023/A:1022364823330

RAPD analysis in selected cultivars of Kapoori and Bangla betel vines (Piper betle L.) were carried out in order to ascertain the relatedness of the two to each other. On the basis of the data from 10 RAPD primers, it was found that the Kapoori cultivars were more heterogeneous (mean SI = 0.521) while the Bangla cultivars were mostly similar to each other (mean SI = 0.884). Within each type, the overall polymorphism of RAPD bands was more than 70 %. When RAPD band data for both types of cultivars were considered cumulatively, the two were clearly separated from each other. In fact only six bands out of a total of 60 bands were found to be common...

Comparative Study of Seed Protein Profiles in the Genus Pisum

S.S. Jha, D. Ohri

Biologia plantarum 2002, 45:529-532 | DOI: 10.1023/A:1022316907401

Seed protein profiles of 24 wild and cultivated taxa of Pisum have been compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis. No consistent differences were detected either among wild taxa or between wild and cultivated taxa. This shows that Pisum forms a single-species complex on the basis of seed protein profiles.

Ornithine Carbamoyltransferase from Spinacea oleracea: Purification and Characterization

E. Bellocco, C. Di Salvo, G. Laganà, A. Galtieri, S. Ficarra, A. Kotyk, U. Leuzzi

Biologia plantarum 2002, 45:533-538 | DOI: 10.1023/A:1022368924239

Ornithine carbamoyltransferase (OCT) from spinach (Spinacea oleracea L.) was purified to homogeneity and studied for some kinetic and structural properties. The enzyme showed a specific activity of 436 U mg^-1, its molecular mass was approximately 118 kDa as estimated by Sephacryl S-200 gel filtration chromatography, the purified protein ran as a single band of 38 kDa in sodium dodecyl sulfate-polyacryamide gel electrophoresis. The enzyme catalyses an ordered bi-bi-sequential reaction in which carbamoyl phosphate binds first, followed by L-ornithine; L-citrulline leaves first, followed by phosphate. The Michaelis constant was...

Some Properties of Proteolytic Enzymes and Storage Proteins in Recalcitrant and Orthodox Seeds of Araucaria

L. Galleschi, A. Capocchi, S. Ghiringhelli, F. Saviozzi

Biologia plantarum 2002, 45:539-544 | DOI: 10.1023/A:1022321008309

Araucaria bidwillii Hook. and Araucaria cunninghamii Don D. are two species of conifers whose seeds belong to different physiological categories: A. bidwillii seeds are recalcitrant, while A. cunninghamii seeds are orthodox. The extraction of enzymes and storage proteins was carried out from A. bidwillii and A. cunninghamii megagametophytes. The endopeptidase activities of both species were assayed with azocasein and with haemoglobin; the exopeptidase activities were detected by various N-carbobenzyloxy-dipeptides and L-leucine p-nitroanilide. The use of appropriate proteinase inhibitors, i.e....

Effect of Salt Stress on the Superoxide Dismutase Activity in Leaves of Citrus limonum in Different Rootstock-Scion Combinations

M.S. Almansa, J.A. Hernandez, A. Jimenez, M.A. Botella, F. Sevilla

Biologia plantarum 2002, 45:545-549 | DOI: 10.1023/A:1022373025148

The effect of salinity on leaf superoxide dismutase (SOD) activity of lemon trees of different rootstock-scion combinations was studied. In leaves from Citrus limonum cv.Verna scions on Citrus macrophylla and C. reticulata rootstocks, salinity treatment clearly caused a significant depression in both Fe-SOD and Mn-SOD activities and an increase in Cu,Zn-SOD activity. However, in leaves from Citrus limonum on Citrus aurantium rootstook, the reduction observed in the activity values of Fe-SODs and Mn-SODs was not statistically significant. Salt stress also produced a decrease in the content of soluble proteins and chlorophylls....

Diamine Oxidase Activity During the Germinative and Post-Germinative Growth of the Embryonic Axis in Chickpea Seeds

A.J. Matilla, S. Garcia, M. Bueno

Biologia plantarum 2002, 45:551-556 | DOI: 10.1023/A:1022325109218

Diamine oxidase (DAO, EC 1.4.3.6.), which participates in oxidative catabolism of polyamines (PAs), was not detected in the dry viable chickpea (Cicer arietinum L.) seeds. From the time when the embryonic axis acquired an aerobic metabolism, DAO increased concomitantly with the growth of the embryonic axis and at the same time with the deterioration of the cotyledons, although in these organs the values were clearly lower than in the axis. The highest DAO activity in the embryonic axis of seedlings grown for 72 and 96 h was found in the elongation, differentiation and hypocotyl zones, while the lowest was in the apex and plumule. The absence...

Response of Tea Plants to Water Stress

U. Chakraborty, S. Dutta, B.N. Chakraborty

Biologia plantarum 2002, 45:557-562 | DOI: 10.1023/A:1022377126056

Two-year-old potted plants of six Camellia sinensis cultivars (TV-18, TV-26, UPASI-3, UPASI-26, T-78 and HV-39) were subjected to water stress for 4, 8 and 12 d. Relative water content (RWC) of leaves of all cultivars declined with water stress, but in the two drought tolerant cultivars (UPASI-3 and UPASI-26), higher RWC were maintained in comparison to the others. Phenol content and activities of phenylalanineammonialyase, polyphenoloxidase and peroxidase initially increased, but decreased during extended drought. Chlorophyll contents decreased, whereas proline contents increased during water stress. SDS-PAGE analysis of proteins revealed increased...

Seasonal Changes of Nitrogen Storage Compounds in a Rhizomatous Grass Calamagrostis epigeios

V. Gloser

Biologia plantarum 2002, 45:563-568 | DOI: 10.1023/A:1022329210127

The seasonal dynamics in content and distribution of N-rich compounds between overwintering organs of Calamagrostis epigeios were examined. Samples were taken both from plants grown in natural conditions and in containers with controlled nutrient supply. There were significant changes in content of nitrate, free amino acids and soluble protein in all investigated plant parts during the course of a year. Amino acids showed both the highest maximum and seasonal fluctuation among the all N compounds observed and, therefore, appear to have a central role in N storage. Their content rises in the autumn, remains stable during winter and declines quickly...

Light-Dependent Ammonium Ion Toxicity of Rice Leaves in Response to Phosphinothricin Treatment

Y.-C. Tsai, C.H. Kao

Biologia plantarum 2002, 45:569-573 | DOI: 10.1023/A:1022381226965

Ammonium ion accumulation in detached rice leaves treated with phosphinothricin (PPT), an inhibitior of glutamine synthetase (GS), was investigated in the light and darkness. PPT treatment increased NH₄⁺ content and induced toxicity in rice leaves in the light but not in darkness, suggesting the importance of light in PPT-induced NH₄⁺ toxicity in detached rice leaves. PPT treatment in the light resulted in a decrease of activities of the cytosolic form of GS and the chloroplastic form of GS. The photosynthetic electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea reduced NH₄⁺...

Dashek, W.V. (ed.): Methods in Plant Electron Microscopy and Cytochemistry

H. Synková

Biologia plantarum 2002, 45:574 | DOI: 10.1023/A:1022334832678

Glucose-6-Phosphate Dehydrogenase/6-Phosphogluconate Dehydrogenase Ratio and the Glucose-6-Phosphate, 6-Phosphogluconate and Fructose-6-Phosphate Contents in Tobacco Plants Infected with Potato Virus Y

L. Šindelář, M. Šindelářová

Biologia plantarum 2002, 45:575-580 | DOI: 10.1023/A:1022333311035

The ratio of activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase (G6P DH/6PG DH), and the contents of glucose-6-phosphate (G6P), 6-phosphogluconate (6PG) and fructose-6-phosphate (F6P) were studied at various stages of potato virus Y (PVY) multiplication in Nicotiana tabacum cv. Samsun. G6P DH/6PG DH increased through the experiment from 0.42 to 0.53 in leaves of healthy tobacco, and up to 0.59 in PVY systemically infected leaves. However, these ratios in the ruptured protoplast preparations, and the chloroplast and cytosol fractions of healthy protoplasts were similar to that from infected ones. The ratio lower...

Micropropagation of Spilanthes acmella Murr.

K.V. Saritha, E. Prakash, N. Ramamurthy, C.V. Naidu

Biologia plantarum 2002, 45:581-584 | DOI: 10.1023/A:1022385327873

Multiple shoots of Spilanthes acmella Murr. were induced from hypocotyl segments obtained from 1-week-old seedlings on Murashige and Skoog's (MS) medium containing benzyladenine (BA), isopentenyl adenine, and naphthaleneacetic acid (NAA). High frequency shoot proliferation (95 %) and maximum number of shoots per explant (10 ± 0.6) were recorded with 0.5 mg dm^-3 BA in combination with 0.1 mg dm^-3 NAA. A proliferation was achieved by repeatedly subculturing the nodal segments on shoot multiplication medium. About 95 % of the in vitro shoots developed roots after transfer to half strength MS medium containing...

Two-Dimensional Electrophoretic Analysis of Salicylic Acid-Induced Changes in Polypeptide Pattern of Barley Leaves

M.V. Metodiev, M.I. Kicheva, Zh.G. Stoinova, L.P. Popova

Biologia plantarum 2002, 45:585-588 | DOI: 10.1023/A:1022386816748

The salicylic acid-induced changes in the polypeptide patterns of barley (Hordeum vulgare L.) leaves have been analysed using two-dimensional gel electrophoresis. An optimized 2-D PAGE protocol was used and gave reproducible 2-D gels from leaf crude protein extracts with a high number of detected polypeptides. When applied for 24 h SA affected the expression of a number of soluble proteins. Most of them appeared to be down-regulated. Although no abundant expression of specific proteins was observed, we detected three polypeptides that were present only in SA-treated leaves.

Salinity Induced Changes in α-Amylase Activity During Germination and Early Cotton Seedling Growth

M.Y. Ashraf, G. Sarwar, M. Ashraf, R. Afaf, A. Sattar

Biologia plantarum 2002, 45:589-591 | DOI: 10.1023/A:1022338900818

Salinity induced changes in α-amylase activity in three cotton cultivars (NIAB-Karishma, NIAB-86 and K-115) was studied during germination and early seedling growth under controlled conditions. The increase in NaCl concentration resulted in the decrease in α-amylase activity and break down of starch into reducing and non-reducing sugars in all cultivars, however, it was more pronounced in NIAB-86. K-115 showed highest germination followed by NIAB-Karishma and NIAB-86.

Influence of Brassinosteroids on Antioxidant Enzymes Activity in Tomato Under Different Temperatures

L.M. Mazorra, M. Núñez, M. Hechavarria, F. Coll, M.J. Sánchez-Blanco

Biologia plantarum 2002, 45:593-596 | DOI: 10.1023/A:1022390917656

The effect of brassinosteroids (BRs) on catalase (EC 1.11.1.6), peroxidase (EC 1.11.1.7) and superoxide dismutase (SOD, EC 1.15.1.1) activity in tomato leaf discs was analyzed at 25 and 40 °C. Tomato leaf discs were preincubated for 24 h in Petri dishes with 24-epibrassinolide (EBR) or a polyhydroxylated spirostanic analogue of brassinosteroids (MH5). Both concentrations (10.60 and 2.12 nM) of EBR and MH5 stimulated the activity of SOD at 25 and 40 °C, the MH5-stimulated increase of this enzyme activity was greater. Peroxidase activity was unaffected at 25 °C, while at 40 °C this activity was enhanced by both compounds. The changes in catalase activity...

Effect of NaCl and Proline on Bean Seedlings Cultured in vitro

Y. Demir, I. Kocaçalişkan

Biologia plantarum 2002, 45:597-599 | DOI: 10.1023/A:1022343101727

Effects of NaCl (150 mM), proline (10 mM) and their combination on growth and contents of chlorophyll, proline and protein of bean (Phaseolus vulgaris cv. Kizilhaç) seedlings in vitro were investigated. NaCl decreased seedling growth. Proline added to control seedlings did not change seedling growth but decreased chlorophyll and increased protein contents. When proline added to NaCl-treated seedlings growth was increased in comparison with NaCl-treated only. Thus, proline alleviated salinity stress in bean seedlings.

Chilling Induced Oxidative Stress in Germinating Wheat Grains as Affected by Water Stress and Calcium

H. Nayyar, S.K. Kaushal

Biologia plantarum 2002, 45:601-604 | DOI: 10.1023/A:1022308809328

Wheat (Triticum aestivum L.) plants were subjected to mild water stress during grain filling at milk (early, medium, and late) and dough (early, soft, hard) stages. The grains harvested from stressed plants were subjected to low temperature stress of 10 °C for 24 h in presence or absence of 1 mM CaCl₂, and embryos were examined for oxidative injury. The embryos of grains water stressed at milk and soft dough stages showed lowest contents of H₂O₂ and malondialdehyde and highest membrane stability index, ascorbic acid content, and activities of catalase, ascorbate peroxidase, and superoxide dismutase as compared...

Putrescine Effect on Nitrate Reductase Activity, Organic Nitrogen, Protein, and Growth in Heavy Metal and Salinity Stressed Mustard Seedlings

D.B. Singh, S. Varma, S.N. Mishra

Biologia plantarum 2002, 45:605-608 | DOI: 10.1023/A:1022360612976

Putrescine effect on nitrate reductase activity, organic nitrogen and protein contents, and plant growth under Cd or Pb (0.1 - 2 mM) and salinity (5 and 100 mM NaCl) stresses was examined in Indian mustard (Brassica juncea L. cv. RH-30) seedlings. Cd or Pb and salinity inhibited nitrate reductase activity and decreased organic nitrogen and protein contents in leaf tissue. The increased nitrate reductase activity induced by putrescine was correlated with increased organic nitrogen and protein contents and growth of plants.

Callus Growth and Proline Accumulation in Response to Sorbitol and Sucrose-Induced Osmotic Stress in Rice

J.M. Al-Khayri, A.M. Al-Bahrany

Biologia plantarum 2002, 45:609-611 | DOI: 10.1023/A:1022380827034

This study investigated the influence of osmotic stress, induced by sorbitol and sucrose combinations, on growth and proline accumulation in callus cultures of rice (Oryza sativa L.). Dehusked mature seeds, cv. Hassawi, were induced to callus on MS medium supplemented with 4.52 µM 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.32 µM 6-furfurylaminopurine (kinetin). The medium also contained 29.2, 58.4, 87.6, and 116.8 mM sucrose combined with 0, 54.9, 109.8, and 164.7 mM sorbitol. Callus formation was observed in about 35 % of the cultured seeds irrespective of the sugar treatment. An increase in callus mass was observed as sucrose...

Does Spirodela punctata break P-C bonds?

K.M. Janas, Z. Romanowska-Duda

Biologia plantarum 2002, 45:613-615 | DOI: 10.1023/A:1022347927942

Spirodela punctata was cultivated on phosphate-deficient medium (-P_i) with racemic 1-amino-2-phenylethylphosphonic acid (PheP) as a source of P_i. The growth of duckweed was inversely correlated with PheP concentration. The growth of plants on medium -P_i with 0.1 M PheP was accelerated whereas with 0.001 mM PheP was slower than in -P_i control. PheP at low concentrations decreased loss of chlorophyll in comparison with -P_i plants. Content of anthocyanins decreased but activity of the extractable constitutive phosphatases of pH 6.0 and pH 7.5 increased along with increasing concentration of...

Alleviation of Salinity-Induced Dormancy in Perennial Grasses

S. Gulzar, M.A. Khan

Biologia plantarum 2002, 45:617-619 | DOI: 10.1023/A:1022352012012

All seeds of Aeluropus lagopoides and Urochondra setulosa germinated under non-saline conditions except for Sporobolus ioclados which showed only 40 % germination. Increase in salinity substantially inhibited germination and few seeds germinated at 400 mM NaCl. Germination at 200 mM NaCl was alleviated in U. setulosa by the application of gibberellic acid and fusicoccin, in A. lagopoides by thiourea, betaine, kinetin, fusicoccin and ethephon, and in S. ioclados by gibberellin and ethephon. High salinity (400 mM NaCl) induced germination inhibition was alleviated by proline, kinetin, fusicoccin and ethephon...

Response of Eggplant to Nitrogen Supply: Molybdenum-Nitrate Relationships

G. Víllora, D.A. Moreno, L. Romero

Biologia plantarum 2002, 45:621-623 | DOI: 10.1023/A:1022304128851

Greenhouse experiments were conducted in two years (1993-1994) with eggplants supplied with 1, 2 or 4 mM NH₄NO₃ as the N source in order to determine its influence on molybdenum (Mo) and nitrate (NO₃^-) content in leaf blades, petioles, and fruits as well as leaf nitrate reductase (NR) activity. The results reveal that 2 and 4 mM NH₄NO₃ altered shoot Mo distribution and thus affecting the NR activity.

Induction of Oxidative Stress in Roots of Oryza sativa L. in Response to Salt Stress

M.H. Khan, S.K. Panda

Biologia plantarum 2002, 45:625-627 | DOI: 10.1023/A:1022356112921

With the imposition of salt stress (0.5 to 3 % NaCl or CaCl₂) a decrease in germination rate and accumulation of proline was observed in the root tissue. Both NaCl and CaCl₂ solutions induced an increase in the total peroxide content and lipid peroxidation and decrease in catalase, guaiacol peroxidase and superoxide dismutase activities in root tissues suggesting an oxidative stress in the salt sensitive rice cultivar.

Light Induced Enhancement in Proline Levels Under Stress is Regulated by Non-Photosynthetic Events

S. Arora, P.P. Saradhi

Biologia plantarum 2002, 45:629-632 | DOI: 10.1023/A:1022355721123

Vigna radiata (L.) seedlings (5-d-old) were exposed to different concentrations of NaCl in light and in dark. The content of proline in the shoots increased with an increase in NaCl concentration, in light as well as in dark. But, irrespective of the concentration of NaCl, proline accumulation in the shoots was higher in light than in dark. Pretreatment of seedlings with dichlorophenyl dimethyl urea (DCMU) did not make any significant difference in light promoted stress induced proline accumulation. As DCMU is a potent inhibitor of photosynthetic electron transport, the light reaction of photosynthesis was not responsible for the observed light...

NaCl-Induced Changes in Putrescine Content and Diamine Oxidase Activity in Roots of Rice Seedlings

C.C. Lin, C.H. Kao

Biologia plantarum 2002, 45:633-636 | DOI: 10.1023/A:1022396408673

The effects of NaCl on putrescine (Put) content and diamine oxidase (DAO) activity in roots of rice seedlings were examined. NaCl treatment lowered the content of Put and increased the activity of DAO in roots. Our current results indicate that Cl^- is not required for NaCl-induced decline in Put content and increase in DAO activity in roots. Put content in roots of rice seedlings exposed to NaCl is possibly regulated by DAO activity.

Comparison of Barley Response to Short-Term Cold or Dehydration

Z. Faltusová-Kadlecová, M. Faltus, I. Prášil

Biologia plantarum 2002, 45:637-639 | DOI: 10.1023/A:1022353316419

Abscisic acid (ABA) content and relative water content (RWC) in second fully expanded leaves of cold hardened plants and in dehydrated leaves of freezing tolerant barley (Hordeum vulgare L. cv. Lunet) were compared. ABA content and RWC in leaves did not change during the first day of cold hardening. On the contrary, dehydration of leaves led to a decrease of RWC and to an increase of ABA content.

Zdeněk Šesták Septuagenarian!

Jiří Čatský

Biologia plantarum 2002, 45:I-II | DOI: 10.1023/A:1022300908570