Tag Archives: phenylalanine ammonia-lyase
Organo-specific accumulation of phenolic compounds in a buckwheat seedlings under aluminium-acid stress
O. E. Smirnov, A. M. Kosyan, Yu. V. Pryimak,
O. I. Kosyk, N. Yu. Taran
ESC “Institute of Biology and Medicine”, Taras Shevchenko National University of Kyiv, Ukraine;
e-mail: plantaphys@gmail.com
Received: 19 September 2020; Accepted: 17 December 2020
Toxic effect of aluminum contamination is one of the causes of valuable crops yield loss all over the world. It is considered that plants’ phenolic compounds play a key role in aluminium detoxification by chelation of aluminium ions in the aboveground part of aluminium-accumulating plants. However, recent evidence shows the chelating ligands involvement in both the internal and external aluminium detoxification in plants. The aim of the study was to determine the total phenolic compounds, flavonoids, anthocyanins accumulation and the activity of phenylalanine ammonia-lyase (PAL) as the key enzyme in phenolic compounds synthesis in seedlings of common (Fagopyrum esculentum Moench.) and tartary (Fagopyrum tataricum (L.) Gaertn.) buckwheat in response to the chronic aluminium-acid stress. It was recorded that addition of 50 μM Al2(SO4)3·18H2O to the nutrient medium led to the accumulation of phenolic compounds in all organs of both studied species on the tenth day of the plant exposure to stress. Species-specific and organ-specific accumulation of certain classes of phenylpropanoids was recorded. On the tenth day of stress, PAL activity was increased in the leaf tissues of both buckwheat species, but was decreased in common buckwheat root tissues and no statistically significant changes were observed in tartary buckwheat root tissues. Species and organ specificity of phenylpropanoids accumulation in the studied species is considered to be an adaptive reaction under conditions of aluminum stress.
Phenolic compounds in plants: biogenesis and functions
L. M. Babenko1, O. E. Smirnov2, K. O. Romanenko1,
O. K. Trunova3, I. V. Kosakіvskа1
1M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Kyiv;
2Educational and Scientific Center “Institute of Biology and Medicine”, Taras Shevchenko National University of Kyiv, Ukraine;
3V.I. Vernadsky Institute of General and Inorganic Chemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: lilia.babenko@gmail.com
Received: 05 November 2018; Accepted: 14 March 2019
Phenolic compounds (PCs) in plants play an important role in growth control and have antioxidant, structural, attractant, signaling and protective functions. Information on the discovery, study and identification of phenolic compounds in plants, their role in the complex system of secondary metabolites has been analyzed and summarized. The functions of PCs at the macromolecular, cellular as well as organism and population levels are described. The pathways of PCs formation, enzymes responsible for their synthesis and the plasticity of the synthesis in a plant cell are highlighted. The involvement of PCs in the plant breathing, photosynthesis, oxidation-reduction processes and regulation of the plants physiological state are discussed.
Phenylalanine ammonia-lyase activity and content of flavonoid compounds in wheat seedlings at the action of hypothermia and hydrogen sulfide donor
Yu. E. Kolupaev1,2, E. I. Horielova1, T. O. Yastreb1, Yu. V. Popov3, N. I. Ryabchun3
1Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@ukr.net;
2Karazin Kharkiv National University, Ukraine;
3Yuryev Рlant Production Institute, National Academy of Agrarian Sciences of Ukraine, Kharkiv
At present hydrogen sulfide (H2S) is considered as one of the signal mediators in plant cells. However, its role in formation of plant resistance to low temperatures and, in particular, in regulation of secondary metabolism under stress conditions remains poorly understood. The influence of H2S donor sodium hydrosulfide (NaHS) on phenylalanine ammonia-lyase (PAL) activity and content of flavonoids in wheat seedlings at normal temperature (21 °C) and under cold hardening conditions (7 days at 3 °C) was studied. After 2 days of the hardening temperature, a transient increase in PAL activity was noted. Also, activity of the enzyme was increased by treatment of plants with 0.1 or 0.5 mM NaHS under normal temperature conditions and especially at the background of cold hardening. By themselves, the cold hardening and the action of H2S donor caused an increase in total content of flavonoids and amount of anthocyanins. With the combination of hypothermia and treatment of seedlings with NaHS, this effect enlarged and the total content of flavonoids increased by 3.8, and anthocyanins increased by 1.8 times in comparison to the control. Treatment with the H2S donor caused a decrease in content of the lipid peroxidation product malonic dialdehyde in seedlings after the action of hardening temperature, and especially after their freezing at –5 °C. Also, under the influence of NaHS, survival of hardened and unhardened seedlings after cryostress increased. It was concluded that one of the mechanisms of the positive influence of the H2S donor on resistance of wheat seedlings to hypothermia is the PAL-dependent accumulation of flavonoid compounds, which have a high antioxidant activity, and a decrease in effects of secondary oxidative stress.
Phenylalanine ammonia-lyase activity and anthocyanin content in different varieties of lettuce under the cadmium influence
O. I. Kosyk, I. M. Khomenko, L. M. Batsmanova, N. Yu. Taran
Educational and Scientific Centre “Institute of Biology and Medicine”,
Taras Shevchenko National University of Kyiv;
e-mail: i.m.homenko@gmail.com
Cadmium ions influence on the content of anthocyanins as non-plastid pigments and the activity of phenylalanine ammonia-lyase (EC 4.3.1.24) as primary enzyme of their biosynthesis in two lettuce varieties (Lactuca sativa L.) with different anthocyanin content was investigated. The increases in anthocyanin content and enzymatic activity of phenylalanine ammonia-lyase of both lettuce plant varieties during the 14-day exposure in solution of cadmium nitrate (0.1 mmol) were established. The difference in levels of adaptive capacity in two lettuce varieties with different content of anthocyanins under the effect of cadmium ions was revealed. The indexes of tolerance have shown faster adaptive response and higher resistance in red variety plants, compared with plants of the green lettuce variety. These data are consistent with the corresponding changes in anthocyanins content and indicate their active participation in neutralizing the negative impact of cadmium stress.
Response of phenolic metabolism induced by aluminium toxicity in Fagopyrum esculentum Moench. plants
O. E. Smirnov, A. M. Kosyan, O. I. Kosyk, N. Yu. Taran
Educational and Scientific Centre “Institute of Biology”,
Taras Shevchenko National University of Kyiv, Ukraine;
e-mail: plantaphys@gmail.com
Buckwheat genus (Fagopyrum Mill.) is one of the aluminium tolerant taxonomic units of plants. The aim of the study was an evaluation of the aluminium (50 µM) effect on phenolic accumulation in various parts of buckwheat plants (Fagopyrum esculentum Moench.). Detection of increasing of total phenolic content, changes in flavonoid and anthocyanin content and phenylalanine ammonia-lyase activity (PAL) were revealed over a period of 10 days of exposure to aluminium. The most significant effects of aluminium treatment on phenolic compounds accumulation were total phenolic content increasing (by 27.2%) and PAL activity rising by 2.5 times observed in leaves tissues. Received data could be helpful to understand the aluminium tolerance principles and relationships of phenolic compounds to aluminium phytotoxicity.