Department Plant Stress Molecular Biology

Head: Professor Klimentina Demirevska, DrSc

The department of “Plant Stress Molecular Biology” was founded in 2007 by merging the “Plant Stress Molecular Biology” laboratory and the department of Genomics and Proteomics.

• Main purpose – to investigate the physiological and biochemical processes in seeds and plants under different kinds of stresses and find possibilities to increase their stress resistance.
• The studies are focused on the response of seeds and plants to UV-B irradiation, low and high temperature, changes in the light regime and photoinhibition, salt and drought stress, and the effect of phytochormones.
• The research concerns: the stress inducible proteins (heat shock proteins, chaperonins, dehydrins, and others); changes in the antioxidant protection and proteolytic activity; changes in the expression of specific plant proteins such as Rubisco, Rubisco binding protein, Rubisco activase, and others; stress markers; flavonoids; activity of the photosynthetic electron transport; the net photosynthesis. Cross-acclimation mechanisms are studied.

Future studies will be aimed at:

• Expression of stress inducible genes coding for specific plant proteins responsible for stress resistance.
• Search of specific protein or non-protein stress markers.
• Production of specific antibodies for characterization of stressed plants.
• Search of suitable treatments for increasing plant stress resistance.

Scientific cooperation

Between Academies:

• National Research Center, Botany Department, Cairo, Egypt.
• Hacettepe University – TUBITAK, Ankara, Turkey.
• Institute of Botany, National Academy of Sciences in Ukraine, Kiev, Ukraine.
• Institute of Biometeorology, Florence, Italy.
• Institute of Experimental Botany, Prague, Czech Republic.

Between Institutes:

• Institute of Plant Sciences, University of Bern, Switzwrland.
• IGER/IBERS University, Aberystwyth, England.
• Institutes of Biophysics, Genetics and Biology and Immunology of Reproduction, BAS.
• With the Institute of Agriculture in Karnobat.
• With the Dobrudja Agricultural Institute in General Toshevo.

Most important achievements

• UV-B irradiation provoked decrease in the rate of photosynthesis and chlorophyll content and stimulated synthesis of carotenoids and endogenous proline in barley seedlings. UV-B treatment lead to increase of H₂O₂ in the green and greening plants but has no effect on etiolated. Activities of antioxidant enzymes catalase, superoxide dismutase, and peroxidase enhanced due to greening, as well as to UV-B irradiation, but were not accompanied by changes in isoenzymes pattern.
• Physiological changes in 3 rice varieties with different sensitivity towards UV-B stress were studied. Data on CO₂ fixation rate, photochemical activity of PSII, and infrared-induced oxidation state of P₇₀₀ supported the different sensitivity of the varieties to UV-B. Free proline content and H₂O₂ level raised as a result of UV-B treatment. CAT activity increased reaching highest values in the most resistant variety. The activity of all isoenzyme forms of POX increased. Rubisco protein was significantly affected by UV-B treatment.
• Combined treatment of the green algae Choricystis and Chlorella with Sanosyl and high temperature resulted in appearance of a new isoenzyme in their CAT profiles. The sole treatment with the oxidant Sanosyl revealed the same isoenzyme band confirming that abiotic and biotic stress factors both lead to oxidative stress at molecular level.
• Relationship between seedling growth, POX and SOD activity in roots and shoots of wheat seedlings treated with low/high temperature was established.
• Field drought lead to higher oxidative stress (higher membrane damage, changes in the content of H₂O₂, and increase in SOD and CAT activities) in the drought-sensitive winter wheat varieties compared to resistant ones. Differences in the response of SOD isoforms were observed. Variety-specific differences in proteolytic response were revealed.
• Rubisco binding protein, catalytic and regulatory subunit of Clp protease complex increased in the leaves of wheat plants subjected to severe but recoverable drought stress. The level of Rubisco activase changed slightly.
• The increased basal levels of ABA in some wheat varieties subjected to gradual water stress and subsequent recovery of water status were a prerequisite for drought tolerance at early vegetation stage. Significant differences in gene expression of two heat shock proteins in the first leaf of drought-treated young wheat plants were established.
• Two-day darkening of zucchini cotyledons induced a drastic drop in the rate of total chloroplast transcription while the biosynthesis of total nuclear RNA was much less affected. The inhibition measured in individually darkened cotyledons was compared to the intact darkened plants.

Research projects

• “Response of some monocot and dicot plants to UV-B and salt stresses in interaction with heat hardening treatments (cross adaptation and recovery)”. Joint project with the National Research Center, Botany Department, Cairo, Egipt, 2006-2008 - Project leader: Assoc. Prof. I. Fedina.
• “Physiological reaction of barley plants to UV-B irradiation. Cross-adaptation”. Financial support from the National Science Fund, Bulgaria, 2006-2008 - Project leader: Assoc. Prof. I. Fedina.
• “Drought induced leaf protein alterations” (DILPA). The financial support is from SCOPES (Scientific Cooperation between Eastern Europe and Switzerland). Joint research project between IPP – BAS and the Institute of Plant Sciences, University of Bern, Switzerland, 2006-2008 - Project leaders: Prof. K. Demirevska and Prof. U. Feller.
• “Drought induced changes in the leaf proteins of wheat varieties differing in drought resistance”. Financial support from the National Science Fund, Bulgaria, 2006-2008 - Project leader: Prof. K. Demirevska.
• “Biochemical and ultrastructural characteristics of cereal leaves submitted to abiotic stress”. The project is in the frame of “PISA” – IPP. Financial support from the National Science Fund, Bulgaria, 2005-2007 - Coordinator: Prof. K. Demirevska.
• “Investigation of transcription in chloroplast genome and the functional activity of photosynthetic apparatus in intact zucchini cotyledons under different light regimes”. Financial support from the National Science Fund, Bulgaria - 2006-2008 Project leader: As. Prof. K. Mishev, PhD Student, Advisor: Assoc. Prof. E. Ananiev.
• “Mechanisms of senescence regulation in zucchini.” Financial support from the National Science Fund, Bulgaria, 2004-2008 - Project leader: Assist. Prof. Kalina Ananieva, Participant: As. Prof. K. Mishev, PhD Student.
• “Investigation of active oxidant species – antioxidant interactions under different stress conditions”. BAS project - Project leader: Assoc. Prof. D. Nedeva.
• “Perspectives for the cultivation of fibre nettle (Urtica dioica L.) in mediterranean environmental and in changing environments”. The project is between IPP and the Institute of biometeorology in Firence, Italy /2007-2009/. Project leader: Assoc. Prof. K. Georgieva (Photosynthesis Department); Participant: Assoc. Prof. I. Fedina.
• “Proteins as biomarkers of plant resistance”. The project is between IPP and Institute of Botany in Kiev, National Academy of Sciences in Ukraine, 2007-2011 - Project leader: Prof. K. Demirevska.
• “The role of redox state on regulation of proteolysis under anoxia” The project is between IPP and IGER/IBERS University, Aberystwyth, England, 2008-2009. Project leader: Prof. K. Demirevska.
• “Biochemical and physiological characteristics of Arabidopsis thaliana mutants with changed programmed cell death expression induced by H₂O₂”. The project is with the Institute of Genetics BAS, 2006-2008. Project leader: Prof. A. Edreva, Participant: Prof. K. Demirevska.
• “Cytokinin metabolism and gene expression during induced senescence and subsequent recovery in cotyledons of Cucurbita pepo L. (zucchini)”. Joint research project between Institute of Plant Physiologу “Acad. M. Popov” and Institute of Experimental Botany, Praga (2006-2008). Participant: As. Prof. Kiril Mishev, PhD Student, Project leader: Assist. Prof. K. Ananieva.

Staff

Staff of the Department - 12 members: 1 Professor, DrSc; 1 Associate Professor, PhD; 3 Assistant Professors, PhD; 2 PhD students; 5 Researchers.

To contact particular colleague please dial +359-2-979- followed by the extension number given below:

Selected Publications

2009
Demirevska K., Zasheva D., Dimitrov R., Simova-Stoilova L., Stamenova M., Feller U. (2009) - Drought stress effects on Rubisco in wheat: changes in the Rubisco large subunit. Acta Physiol. Plantarum, 31: 1129-1138.
Georgiev, M., Abrashev R., Krumova E., Demirevska K., Ilieva M., Angelova M. (2009) - Rosmarinic acid andantioxidant enzyme activities in Lavandula vera MM cell suspension  cultures: A comparative study. Applied Biochemistry and Biotechnology, 159: 415-425.
Fedina, I., Georgieva K., Velitchkova M., Nedeva D., Chakirlar H.(2009) - UV-B response of etiolated and greening barley seedlings. Acta Biologica Hungarica  60: 195-210.
Fedina, I., Nedeva D., Georgieva K., Velitchkova M.(2009) - Methyl jasmonate counteract UV-B stress in barley seedlings – J. Agron. Crop Science 195: 204-219.
Fedina, I., Nedeva, D., Cicek  N. (2009) - Pre-treatment with H₂O₂ induces salt tolerance in barley seedlings – Biologia Plantarum, 53 (2): 321-324.
Fedina, I.S. and Velitchkova M. Y. (2009) - Physiological responses of higher plants to UV-B radiation – review in the book Climate change and crops, Series: Environmental Science and Engineering, Singh, S.N. (Ed.), Springer, Germany, 283-307.
Mishev K., Stefanov D., Ananieva K., Slavov C., Ananiev E.D. (2009) - Different effects of dark treatment on pigment composition and photosystem I and II activities in intact cotyledons and primary leaves of Cucurbita pepo (zucchini). Plant Growth Regulation, 58: 61-71.
Simova-Stoilova L., Demirevska K., Petrova T., Tsenov N., Feller U. (2009)  Antioxidative protection and proteolytic activity in tolerant and sensitive wheat (Triticum aestivum L.) varieties subjected to long-term field drought, Plant Growth Regulation 58 (1), 107-117.
Vaseva I., Todorova D., Malbeck J., Travničkova A., Machačkova I. (2009) Mild temperature stress modulates cytokinin content and cytokinin oxidase/dehydrogenase activity in young pea plants. Acta Agronomica Hungarica 57(1), 33–40.
Vassileva V., Simova-Stoilova L., Demirevska K., Feller U. (2009) Variety-specific response of wheat leaf mitochondria to drought stress. J Plant Res., 122 (4): 445-454.

In press:
Demirevska-Kepova K., Simova-Stoilova L., Fedina I., Georgieva K., Kunert K. Response of Transformed with Oryzacystatin I Tobacco Plants to Drought, Heat and Light Stress. J. Agr. Crop Sci. (in press), DOI: 10.1111/j.1439-037X.2009.00396
Grigorova B. Review Plant heat shock proteins as molecular  chaperones in normal and stress conditions. In:  Handbook of Molecular Chaperones: Roles, Structures and Mechanisms. Nova Science Publishers Ltd.(in press). 
Grigorova B., Vaseva I. , Demirevska K., Feller U. Combined drought and heat stress in wheat: changes in some heat shock proteins. Biologia Plantarum (under revision), 2009.
Fedina, I., Hidema J., Velitchkova M., Georgieva K., Nedeva D.- UV-B induced stress responses in three rice cultivars Biologia Plantarum (in press).
Simova L., Vaseva I., Grigorova B., Demirevska K., Feller U. Proteolytic activity and cysteine protease expression in wheat leaves under severe soil drought and recovery. Plant Physiol. Biochem. doi:10.1016/j.plaphy.2009.11.003  (in press).  
Vaseva I., Grigorova B., Simova-Stoilova L., Demirevska K., Feller U. Abscisic acid and LEA profile changes in winter wheat under progressive drought stress. Plant Biol. (in press), DOI: 10.1111/j.1438-8677.2009.00269.x  2009.

2008
Demirevska K., L. Simova-Stoilova, V.Vassileva, I. Vaseva, B. Grigorova, U. Feller (2008) - Drought induced leaf protein alterations in sensitive and tolerant wheat varieties. General and Applied Plant Physiology, Special Issue 34 (1-2) 79-102.
U. Feller, I. Anders, K. Demirevska (2008) - Degradation of Rubisco and other chloroplast proteins under abiotic stress. General and Applied Plant Physiology, Special Issue 34 (1-2) 5-18.
Demirevska K., L. Simova-Stoilova, V. Vassileva, Urs Feller (2008) - Drought response of Rubisco and some ATP-dependent chaperone proteins in wheat plants”. Plant Growth Regulation 56:97–106.
Nuran Cicek, Husnu Chakirlar, Ivanka Fedina, Katya Georgieva, Maya Velitchkova (2008) - NaCl Induced Cross-Acclimation to UV-B Radiation in Four Barley (Hordeum vulgare L.) Cultivars. Acta Physiologiae Plantarum, 30:561–567.
Ivanka S. Fedina, Maya Y. Velitchkova (2008) - Physiological responses of higher plants to UV-B radiation – review in the book Climate change and crops, Springer Germany.
Sabeva S., D. Nedeva (2008) - Antioxidant enzymes in germinating wheat seeds as affected by dehydration stress, ABA and hydrogen peroxide. Acta Agronomica Hungarica 56, 2, 113-127.
Simova-Stoilova L., K. Demirevska, T. Petrova, N. Tsenov, U. Feller (2008) - Antioxidative protection in wheat varieties under severe recoverable drought at seedling stage. Plant Soil and Environment 54, (12): 529–536.
Vaseva I., D. Todorova, J. Malbeck, Trávníčková A., Macháčková I. (2008) - Response of cytokinin pool and cytokinin oxidase/dehydrogenase activity to abscisic acid exhibits organ specificity in peas. Acta Physiologiae Plantarum 30, (2) 151-155.
Kirova E., Tzvetkova N., Vaseva I., Ignatov G. (2008) - Photosynthetic responses of nitrate-fed and nitrogen-fixing soybeans to progressive water stress. Journal of Plant Nutrition 31: 445–458.
Ananieva K., Ananiev E.D., Mishev K., Georgieva K., Tzvetkova N., van Staden J. (2008) - Changes in photosynthetic capacity and polypeptide patterns during natural senescence and rejuvenation of Cucurbita pepo L. (zucchini) cotyledons. Plant Growth Regulation, 54: 23-29.
Todorova D., D. Nedeva, R. Abrashev, K. Tsekova (2008) - Cd (II) stress response during the growth of Aspergillus niger B.47. Journal of Applied Microbiology, 104: 178-184.
Georgiev, M., R. Abrashev, E. Krumova, K. Demirevska, M. Ilieva, M. Angelova (2008) - Rosmarinic acid andantioxidant enzyme activities in Lavandula vera MM cell suspension cultures: A comparative study. Applied Biochemistry and Biotechnology (in press).
Ivanka Fedina, Katya Georgieva, Maya Velitchkova, Dimitrina Nedeva, Husnu Chakirlar (2008) - UV-B response of etiolated and greening barley seedlings. Acta Bilogica Hungarica (in press).
Fedina, I., Nedeva, D., Nuran Cicek (2008) - Pre-treatment with H₂O₂ induces salt tolerance in barley seedlings. Biol.Plantarum (in press).
Bacalova S., D. Nedeva, J. McKee (2008) - Protein profiles in wheat seedlings subjected to dehydration stress. Applied Ecology and Environmental Research 5, 2 (in press).
Mishev K, D. Stefanov, K. Ananieva, Ch. Slavov, E.D. Ananiev (2008) - Different effects of dark treatment on pigment composition and photosystem I and II activities in intact cotyledons and primary leaves of Cucurbita pepo (zucchini). Plant Growth Regulation (in press).
Simova-Stoilova L., K. Demirevska, T. Petrova, N. Tsenov and U. Feller (2008) - Response of Winter Wheat (Triticum aestivum L.) Varieties to Field Drought: Leaf Antioxidative Protection and Proteolytic Activity in Relation to Yield. Plant Growth Regulation (in press).

2007
Fedina I., K. Georgieva, M. Velitchkova, K. Demirevska, L. Simova (2007) - UV-B induced compounds in green and etiolated barley seedlings. Biol. Plantarum 51:699-706.
Gorinova N., M. Nedkovska, E. Todorovska, L. Simova-Stoilova, Z. Stoyanova, K. Georgieva, K. Demirevska-Kepova, A. Atanassov, R. Herzig (2007) - Improved phytoaccumulation of cadmium by genetically modified tobacco plants (Nicotiana tabacum L.). Physiological and biochemical response of the transformants to cadmium toxicity. Environmental Pollution 145, 161-170.
Todorova D., Vaseva I., Malbeck J., Trávníčková A., Macháčková I., Karanov E. (2007) - Cytokinin oxidase/dehydrogenase activity as a tool in gibberellic acid/cytokinin cross talk. Biol. Plantarum 51 (3): 579-583.
Ananieva K., Ananiev E.D., Mishev K., Georgieva K, Malbeck J., Kaminek M., van Staden J. (2007) - Methyl jasmonate is a more effective senescence-promoting factor in Cucurbita pepo (zucchini) cotyledons when compared with darkness at the early stage of senescence. Journal of Plant Physiology, 164: 1179-1187.

2006
Doncheva, S., Z. Stoyanova, K. Georgieva, D. Nedeva, R. Dikova, G. Zafirov, A. Nikolova (2006) - Exogenous succinate increases resistance of maize plants to copper stress. J. Plant Nutrition and Soil Science, 169 (2), pp. 247-254.
Fedina, I. S., K. Georgieva, Velitchkova, M , I. Grigorova (2006) - Effect of pretreatment of barley seedlings with different salts on the level of UV-B induced and UV-B absorbing compounds compounds as affected by proline and NaCl in Hordeum vulgare L., cv. Alfa. Environ. Exp. Botany 56: 225-230.
Hassan, E., Fedina, I.S., El-Awadi, M.E. (2006) - New pyrimidine derivatives as modulators of plant response to salinity of NaCl. Egyptian Journal of Applied Sciences 27: 21-29.
Fedina I., E. Hasan, K. Georgieva, M. Velitchkova, I. Grigorova (2006) - Effect of chloramphenicol and cycloheximide on the level of UV-B induced compounds in barley seedlings. Egyptian Journal of Applied Sciences, 21:17-29.
Fedina I., Esmat Hasan, Katya Georgieva, Maya Velitchkova, Irena Grigorova (2006) - Effect of chloramphenicol and cycloheximide on the level of UV-B induced compounds in barley seedlings. Egyptian Journal of Applied Sciences, 21:17-29.
Demirevska-Kepova K., L. Simova-Stoilova, Z. Stoyanova, U. Feller (2006) - Cadmium stress in barley: growth, leaf pigment and protein composition and detoxification of reactive oxygen species. J. Plant Nutrition 29, 3, 451-458.
Simova-Stoilova L., V. Vassileva, T. Petrova, N. Tsenov, K. Demirevska, U. Feller (2006) - Proteolytic activity in wheat leaves during drought stress and recovery. General and Applied Plant Physiology Special Issue, 32 (1-2), 91-100.
Vaseva-Gemisheva I., Todorova D., Malbeck J., Travnickova A., Machackova I., Karanov E. (2006) - Cytokinin pool dynamic changes and distribution of cytokinin oxidase/dehydrogenase activity in peas in relation to developmental senescence. Comp. Rend. Bulg. Acad. Sci. 59 (1): 65-70.
Vaseva-Gemisheva I., D. Todorova, E. Karanov. (2006) - Influence of ethylene releasing agent ethrel on cytokinin oxidase/dehydrogenase activity in tissues of Pisum sativum. Comp. Rend. Bulg. Acad. Sci. 59 (3): 301-304.
Vaseva I., Todorova D., Malbeck J., Trávníčková A., Machackova I., Karanov E. (2006) - Two pea varieties differ in cytokinin oxidase/dehydrogenase response to UV-B radiation. General and Applied Plant Physiol, Special Issue – PROCEEDINGS OF THE WORKSHOP ON SUSTAINABILITY, STRESS AND THE BASES OF PLANT RESISTANCE Acad. M. Popov Institute of Plant Physiology 8 September, 2006, Sofia, Bulgaria, 131-138.
Todorova D., Vaseva-Gemisheva I., Petrov P., Stoynova-Bakalova E., Alexieva V., Karanov E., Smith A., Hall M. (2006) - Cytokinin oxidase/dehydrogenase (CKX) activity in wild and ethylene-insensitive mutant eti5 type of Arabidopsis thaliana (L.) Heynh plants and the effect of cytokinin N1-(2-chloro-4-pyridyl)-N2-phenylurea on enzymatic activity and leaf morphology. Acta Physiol. Plantarum 28 (6): 613-617.
Mishev K., Denev I., Radeva G. and Ananiev E.D. (2006) - RNA transcription in isolated chloroplasts during senescence and rejuvenation of intact cotyledons of Cucurbita pepo L. (zucchini). Comptes rendus de l’Academie Bulgare des Sciences, 59: 1287-1293.

2005
Fedina I. S., Velitchkova, M., K. Georgieva, I. Grigorova (2005) - UV-B induced compounds as affected by proline and NaCl in Hordeum vulgare L., cv. Alfa. Environ. Experimental Botany, 54:182-191.
Stefanov B., N. Popova., L. Iliev (2005) - Influence of low temperature treatment on growth and protein composition of young maize seedlings grown in the presence of calcium ions and benzylaminopurine. Compt. Rend. Acad. Bulg. Sci. 58, 2, 89-93.
Nedeva, D., S. Petkova, Y. Angelova, L. Iliev (2005) - The effect of plant growth regulators and chlorsulfuron on electrophoretic profiles of soluble proteins, polypeptides and antioxidant enzymes in maize seedlings. Plant Soil and Environment, 51, 2, 87-93.
Kirova, E., D. Nedeva, A. Nikolova, G. Ignatov (2005) - Changes in the liomass production and total soluble protein spectra of nitrate–fed and nitrogen – fixing soybeans subjected to gradual water stress. Plant, Soil and Environment, 51, (5), 237-242.
Bakalova, S., D. Nedeva (2005) - Effect of dehydration and oxidative stress on protein and polypeptide profiles in germinating wheat seeds. Compt. Rend. Bulg. Acad. Sci., 58 (8) 957-962.
Mincheva, J., D. Nedeva, E. Ananiev (2005) - Effect of abscisic acid, methyl esther of jasmonic acid and benzyladenine on isoenzyme spectra of peroxidase, catalase and superoxide dismutase in young seedlings of Cucurbita pepo L. (Zucchini). Annuaire d’Universite de Sofia “St. Kliment Ohridski”, Biochimie, Biophysique, Biologie moleculaire et Genetique, Microbiologie et Physiologie, V. 96, 1-4, 205-215.
Demirevska-Kepova K., R. Hölzer, L. Simova-Stoilova, U. Feller (2005) - Heat stress effects on Rubisco, Rubisco binding protein and Rubisco activase in wheat leaves. Biologia Plantarum 49 (4): 521-525.
Vaseva-Gemisheva, I., D. Lee, E. Karanov (2005) - Response of cytokinin oxidase/dehydrogenase expression and specific activity to drought stress and herbicide treatments in pea leaves. Plant Growth Regul., 46: 199-208.
Vaseva-Gemisheva I., Sergiev I., Todorova D., Alexieva V., Stanoeva E., Lachkova V., Karanov E. (2005) - Antagonistic effects of triazolo[4,5-d]pyrimidine and pyridylurea derivatives on cytokinin-induced cytokinin oxidase/dehydrogenase activity in young pea plants. Plant Growth Regul. 46: 193-197.
Gemishev O., Vaseva I., Atev A. (2005) - Abscisic acid and ethylen influence on endo-1,4-Β-glucanase activity in Trichoderma reesei I-27. Biotech&Biotech. Equip. 19 (3):106-112.
Todorova D., Genkov T., Vaseva-Gemisheva I., Alexieva V., Karanov E., Smith A., Hall M. (2005) - Effect of temperature stress on the endogenous cytokinin content in Arabidopsis thaliana (L.) Heyn plants. Acta Physiologiae Plantarum 27 (1): 13-18.
Mishev K., Todorov I., and Ananiev E.D. (2005) - Senescence and rejuvenation in intact cotyledons of Cucurbita pepo L. (zucchini). General and Applied Plant Physiology, 31: 15-27.

2004
Kirova, E., D. Nedeva, Ven. Georgieva, A. Nikolova, G. Ignatov (2004) - Changes in the biomass production and polypeptide spectra of nitrate-fed and nitrogen-fixing soybeans subjected to gradual water stress. Ecology and Future, vol. III. 2, 8-13.
Kirova, E., D. Nedeva, A. Nikolova, G. Ignatov (2004) - Changes in the electrophoretic spectra of some antioxidant enzymes in nitrate fed andnitrogen fixing soybeans subjected to gradual water stress. Acta Agronomica Hungarica, 52(4), pp. 323-332.
Bakalova S., A. Nikolova, D. Nedeva (2004) - Isoenzyme profiles of peroxidase, catalase and superoxide dismutase as affected by dehydration stress and ABA during germination of wheat seeds. Bulg. J. Plant Physiol. 30 (1-2), 78-88.
Fedina I. S., K. Georgieva, I. Grigorova (2004) - Response of barley seedlings to UV-B radiation as affected by proline and NaCl. Biol. Plantarum 47: 549-554.
Demirevska-Kepova K., U. Feller (2004) - Heat sensitivity of Rubisco, Rubisco activase and Rubisco binding protein in higher plants (Review). Acta Physiol. Plantarum, 26 (1): 103-114.
Demirevska-Kepova K., L. Simova-Stoilova, Z. Stoyanova, R. Hölzer, U. Feller (2004) - Biochemical changes in barley plants after excessive supply of copper and manganese. Environmental Experimental Botany, 52 (3): 253-266.
Simova-Stoilova L., K. Demirevska-Kepova, Z. Stoyanova (2004) - Antioxidative protection in the leaves of dark-senescing intact barley seedlings. Acta Physiol. Plantarum, 27 (3B): 349-356.
Stoyanova Z., Simova-Stoilova L., K. Demirevska-Kepova (2004) -. Effect of Cd toxicity on growth parameters, photosynthetic pigments, H₂O₂ accumulation and oxidative damage to proteins in young barley plants. Compt. Rend. Acad. Bulg. Sci., 57 (8): 27-32.
Simova-Stoilova L., Z. Stoyanova, K. Demirevska-Kepova (2004) - Effect of Cd toxicity on the levels of some antioxidant enzymes and compounds in the leaves of young barley plants. Compt. Rend. Acad. Bulg. Sci., 57 (8):45-50.
Vaseva-Gemisheva I., Lee D., Alexieva V., Karanov E. (2004) - Cytokinin oxidase/dehydrogenase in Pisum sativum plants during vegetative development. Influence of UV-B irradiation and high temperature on the enzymatic activity. Plant Growth Regul., 42
Gemishev O., Vaseva I., Galabova D., Bankova T., Ilieva S. (2004) - Study of indol-3-acetic acid, isopentenyl adenine and abscisic acid effects over cellulase production in Trihoderma reesei strain I-27. Annuaire de l’Université de Sofia “St. Kl. Ohridski”, vol. 96, livre 4 - 10 Session Scientifique Sofia '03, partie 1, pp 395 – 401.
Doltchinkova V., Georgieva K., Traytcheva N., Slavov Ch., and Mishev K. (2004) - Melittin-induced changes in thylakoid membranes: particle electrophoresis and light scattering study. Biophysical Chemistry, 109: 387-397.
Doltchinkova V., Slavov Ch., and Mishev K. (2004) - Effect of bee venom melittin on biological membranes II. The effect of neutral pH on light scattering of thylakoid membranes in the presence of melittin. Annuaire de l'Universite de Sofia "St. Kliment Ohridski", 96: 245-252.

2003
Petkova S. G., Popova N.I., Angelova Y.M., Stefanov B.J., Iliev L.K. (2003) - Inhibitory effect of some plant growth regulators and chlorsulfuron on growth, protein composition and proteolytic activity of maize seedlings. Biotechnology and Biotechnological Equipment 17 (2), pp. 77-83.
Popova N. I., Petkova S.G., Stefanov B.J., Angelova Y.M., Iliev L. K. (2003) - Influence of jasmonic acid methyl ester on protein content and proteolytic activity of young maize seedlings. Compt. Rend. Acad. Bulg. Sci. 57, 2, 75-80.
Fedina I. S., I.T. Grigorova, K. Georgieva (2003) - Response of barley seedlings to UV-B radiation as affected by NaCl. J. of Plant Physiology 160:205-208.
Georgieva K., I.S. Fedina, L.Maslenkova, V. Peeva (2003) - Responce of chlorina barley mutants to heat stress under low and high light. Functional Plant Biol. 30:515-524.

2002
Angelova Y. M., Petkova S.G., Popova N.I., Stefanov B.J., Iliev L. K. (2002) - Influence of ABA and 4PU-30 on the growth, proteolytic activities and protein composition of maize seedlings. Biologia Plantarum 45 (1), pp. 33-37.
Nikolova, A., D. Nedeva, E. Ananiev (2002) - Izoenzyme patterns of shikimate dehydrogenase in developing and germinating wheat seeds. Annuaire d’Universite de Sofia “St. Kliment Ohridski”, Biochimie, Biophysique, Biologie moleculaire et Genetique, Microbiologie et Physiologie, vol. 95, livre 4, pp 97-104.
Fedina I. S., K. Georgieva, I. Grigorova (2002) - Light-dark changes of proline content in barley leaves under salt stress. Biologia Plantarum 45: 59-63.
Stoyanova Z., L. Simova-Stoilova, K. Demirevska-Kepova, E. Smilova (2002) - Effect of Cu and Mn toxicity on growth parameters and photosynthetic pigments of young barley plants. Compt. Rend. Acad. Bulg. Sci., 55 (8): 83-88.
Simova-Stoilova L., K. Demirevska-Kepova, Z. Stoyanova, E. Smilova (2002) - Effect of Cu and Mn toxicity on leaf protein pattern and Rubisco quantity of young barley plants. Compt. Rend. Acad. Bulg. Sci., 55 (9): 79-84.
Simova-Stoilova L., K. Demirevska-Kepova, Z. Stoyanova (2002) - Ribulose 1,5-bisphosphate carboxylase-oxygenase specific proteolytic activity in barley chloroplasts during dark induced senescence. Photosynthetica, 40 (4): 561-566.
Simova-Stoilova L., K. Demirevska-Kepova (2002) - Purification of Rubisco from higher plants and its immunochemical quantitation in leaf extracts. (Review). Recent Research Developments in Biotechnology and Bioengineering, Special Issue: Biotechnology and Bioengineering of CO₂ fixation: 35-56.

2001
N. Bakardjieva, B. Stefanov, N. Christova (2001) - Effect of calcium ions and 4-PU-30 cytokinin on the protein quantity and the activities of peroxidase, superoxide dismutase and catalase in etiolated maize coleoptiles. Compt. Rend. Acad. Bulg. Sci. 54, 4, 85-88.
Simova-Stoilova L., Zl. Stoyanova, K. Demirevska-Kepova (2001) - Ontogenic changes in leaf pigments, total soluble protein and Rubisco in two barley varieties in relation to yield. Bulgarian J. Plant Physiol., 27 (1-2): 15-24.

2000
A. Nikolova, D. Nedeva (2000) - Electrophoretic patterns of proteins, isolated from soybean seeds grown under conditions of some mineral deficiency and after different periods of storage. Bulg. J. Plant Physiol., 26 (1-2), 27-38.
Kovacheva, A. Nikolova, D. Nedeva, Ch. Christov (2000) - Influence of salicylic acid on the reproductive development of sunflower plants (Heliantus annuus L.). Proceedings of the 2^nd Balkan Botanical Congress, Plants of the Balkan Peninsula in the Next Millenium, ed. N. Golukinrismi, Publishing Section Istanbul University, v. II, 97-101.
Fedina I. S. and K. Benderliev (2000) - Response of Scenedesmus incrassatulus to salt stress as affected by methyl jasmonate. Biologia Plantarum 43: 625-627, 2000.
Fedina I. S. and L. M. Dimova (2000) - Metyl jasmonate - induced polypeptide in Pisum sativum roots soluble proteins. Compt. Rend. Acad. Bulg.Sci 10: 59-62.
Simova-Stoilova L., K. Demirevska-Kepova (2000) - Sensitive avidin-biotin test system for Rubisco specific proteolytic activity. Compt. Rend. Acad. Bulg. Sci., 53 (5): 97-100.
Dolashka-Angelova P., A. A. Syed, K. Demirevska-Kepova, St. Stoeva, W. Voelter (2000) - Purification, characterization and termostability of ribulose 1,5-bisphosphate carboxylase-oxygenase from barley leaves. Z. Naturforsch., 55c: 611-619.
Simova-Stoilova L., K. Demirevska-Kepova, Zl. Stoyanova (2000) - Total and Rubisco specific proteolytic activity during dark induced senescence of barley seedlings. Bulg. J. Plant Physiol., 26 (1-2): 15-26.

1999
Dolashka-Angelova P., Genova L., Stoeva S., Stefanov B., Angelova M., Hristova R., Pashova S., Voelter W. (1999) - Isolation and characterization of a novel superoxide dismutase from fungal strain Humicola lutea 110. Journal of Peptide Research 54 (4), pp. 279-289.
Nedeva D., A Nikolova (1999) - Fresh and dry weight changes and germination capacity of natural or premature desiccated developing wheat seeds. Bulg. J. Plant Physiol, 25, 1-2, 3-15.
Demirevska-Kepova K., L. Simova-Stoilova, S. Kyurkchiev (1999) - Barley leaf Rubisco, Rubisco binding protein and Rubisco activase and their protein/protein interactions. Plant Physiol. (Bulg.), 25 (3-4): 31-44.
Demirevska-Kepova K., L. Simova-Stoilova, St. Kyurkchiev (1999) - Immunochemical proof for protein/protein interactions between Rubisco and Rubisco activase. Proceedings of the Second Balkan Botanical Congress, Istanbul, Turkey, May 14-18, 2: 67-74.

1998
Stefanov B., L. Iliev., N. Popova (1998) - Influence of GA₃ and 4-PU-30 on leaf protein composition, photosynthetic activity, and growth of maize seedlings. Biologia Plantarum 41 (1), pp. 57-63.
Petrova, R., S. Raikov, L. Christova, L. Iiliev, B. Stefanov (1998) - Influence of some growth regulators on the sugarbeet storage. Biotechnology and Biotechnological Equipment (1), pp. 48-50.
B. Stefanov (1998) - Effect of calcium ions on protein composition in germinating maize seeds. Biotechnology and Biotechnological Equipment (1), pp. 116-119.
Stefanov B., L. Iliev., N. Popova, 1998. Protein composition and photosynthetic activity of maize seedlings after treetment with growth regulators of giberrelin and cytokinin types. Compt. Rend. Acad. Bulg. Sci. 51, 5-6, 45-48.
Christov, K., Bakardjieva, N. (1998) - Peroxidase, catalase and superoxide dismutase in long-term desiccated moss Mnium affine and their role in the process of dehydration. In: Plant Peroxidase Newsletter eds: C. Pennel, T. Gaspar, H. Grepin, Univ. Geneva, issue 11, 35-44.
Fedina I. and L. Dimova (1998) - The effect of light on the response of barley leaves to osmotic stress. Compt. Rend. Acad. Bulg.Sci 51: 93-96.
Velitchkova, M. and I. S. Fedina (1998) - Response of Pisum sativum photosynthesis to sallt stress when affected by methyl-jasmonate. Photosynthetica 35: 89-97.
Demirevska-Kepova K., L. Simova-Stoilova, B. Juperlieva-Mateeva, St. Kyurkchiev (1998) - Limited proteolysis of barley Rubisco and recognition of the fragments by monoclonal antibodies, Proceedings of the First Balkan Botanikal Congress, Thessaloniki, Greece, September 19-22, 1997, Progress in Botanical Research, Eds.: I. Tsekos and M. Moustakas, Kluwer Academic Publishers, 211-214.