Biochemical and functional characteristics of the photosynthetic apparatus in vegetative buds and mature needles of Norway spruce (Picea abies L. Karst.)

The biochemical characteristics and functioning of the photosynthetic apparatus in two developmental stages of spruce needles (vegetative buds and mature needles) were compared. Biochemical analysis included quantification of the photosynthetic pigments and immunodetection of the NAPDH-protochlorophyllide oxidoreductase (POR). Photosynthetic performance was monitored as the oxygen production at different light levels applied. Two POR isoforms were detected in buds while only one isoform was present in mature needles. The POR polypeptides in buds were expressed at different levels: the polypeptide of lower molecular mass had a level that was more enhanced than that of higher molecular mass. The most intensive POR signal was observed in mature needles. Concentrations of chlorophylls and carotenoids that were higher in mature needles than in vegetative buds were in accordance with observed POR expression. This reflected on the photosynthetic activity of the investigated organs. Although the chloroplasts in vegetative buds revealed the capability of photosynthesising, the compensation of respiration was not observed even at the highest light level (1100 molPHOTONS m–2s–1) applied. In contrast, mature needles ompensated for respiration successfully at low light level (30 molPHOTONS m–2s–1). Our study showed that chloroplasts in vegetative buds are photosynthetically competent, but limited by their molecular and biochemical background

The annual changes of chloroplast pigments content in current- and previous-year needles of Norway spruce (Picea abies L. Karst.) exposed to cement dust pollution

Chloroplast pigments were shown to be very sensitive to various environmental influences. Changes in chlorophyll and carotenoid content were investigated in Norway spruce needles exposed to alkaline dust emitted by the cement industry. Pigments were extracted from current-year and previous-year needles and quantified spectrophotometrically. In both needle generations all measured pigments were reduced in dust-exposed needles compared to needles harvested from areas not polluted by cement dust. This was due to deceleration of the biosynthetic processes rather than degradation of pigments. Chlorophyll b content appeared to be more sensitive than chlorophyll a in current-year needles while in previous-year needles chlorophyll a was more affected. Total carotenoids needed a longer period of time to reach nearly the same level as in controls. The progression of pigment decline in previous-year needles appeared not to be dramatically accelerated. It might thus be concluded that the spruce needles had sufficient biosynthetic capacity to prevent irreversible damage by cement dust

Utjecaj promijenjene mineralne ishrane na iglice Pančićeve omorike (Picea omorika Pančić) – istraživanje pojedinačnog slučaja

A widespread conifer forest decline in Europe and North America has been expressed through various combinations of symptoms. In our study, unspecific biochemical indicators and histological findings were compared with visually assessed damage symptoms in order to get a detailed diagnosis of a single declining Picea omorika Pančić tree. By measuring the content of photosynthetic pigments and proteins as well as total guaiacol peroxidase activity we confirmed an altered physiological state of the investigated tree. Histological analysis showed specific patterns of decline for Mg and K deficient trees.Sveprisutno propadanje šuma u Europi i sjevernoj Americi manifestira se kao kombinacija različitih simptoma. U provedenom istraživanju usporedili smo nespecifične biokemijske indikatore i histološke nalaze s vizualnom procjenom oštećenja, a s ciljem postavljanja detaljne dijagnoze propadanja jednog stabla Pančićeve omorike (Picea omorika Pančić). Odre|ivanjem sadržaja fotosintetskih pigmenata, proteina i aktivnosti ukupnih gvajacilnih peroksidaza potvr|ena je promjena fiziološkog statusa biljke. Histološke analize pokazale su specifičnosti karakteristične za stabla deficijentna magnezijem i kalijem

Utjecaj promijenjene mineralne ishrane na iglice Pančićeve omorike (Picea omorika Pančić) – istraživanje pojedinačnog slučaja

A widespread conifer forest decline in Europe and North America has been expressed through various combinations of symptoms. In our study, unspecific biochemical indicators and histological findings were compared with visually assessed damage symptoms in order to get a detailed diagnosis of a single declining Picea omorika Pančić tree. By measuring the content of photosynthetic pigments and proteins as well as total guaiacol peroxidase activity we confirmed an altered physiological state of the investigated tree. Histological analysis showed specific patterns of decline for Mg and K deficient trees.Sveprisutno propadanje šuma u Europi i sjevernoj Americi manifestira se kao kombinacija različitih simptoma. U provedenom istraživanju usporedili smo nespecifične biokemijske indikatore i histološke nalaze s vizualnom procjenom oštećenja, a s ciljem postavljanja detaljne dijagnoze propadanja jednog stabla Pančićeve omorike (Picea omorika Pančić). Odre|ivanjem sadržaja fotosintetskih pigmenata, proteina i aktivnosti ukupnih gvajacilnih peroksidaza potvr|ena je promjena fiziološkog statusa biljke. Histološke analize pokazale su specifičnosti karakteristične za stabla deficijentna magnezijem i kalijem

Total soluble proteins amount in vegetative buds and needles of norway spruce during the bursting time

The vegetative buds and later on young needles as well as needles formed in spring previous year of Picea abieswere used in the experimental work. Extracted proteins were determined spectrophotometrically and the amount of dry weight was measured. The data revealed that the dry weight of needles formed in spring previous year was about three times higher than in the vegetative buds at the beginning of investigations. During the sampling period the dry weight in those needles was keeping nearly the same level (39-54%). The increase in dry weight was noticed in the young needles 5-6 weeks after vegetative buds burst. The amount of total soluble proteins in the needles formed previous year was about 140 mg/g of dry weight and it was uniformed during the investigation period. In the vegetative buds the amount of proteins was three times higher than in needles. But, the concentration starts to decrease just before bursting of the vegetative buds as well as during next 2 or 3 weeks when young shoot proliferated. After this decreasing period amount of proteins in newly formed needles briefly reached (in 2 weeks period) the level as it was in vegetative buds. In the following period the decrease of water amount as well as the protein amount in young needles was observed

ANTIOXIDATIVE ACTIVITY OF ANTHOCYANINS FROM SOUR CHERRIES

The aim of this study was to examine antioxidant activities of the anthocyanins isolated from different sour cherry (Prunus cerasus) cultivars. DPPH radical method and photochemiluminescence detection method were employed. The effect of isolated anthocyanins on peroxidase activity was also investigated. In the DPPH method, methanol extract of isolated anthocyanins was employed and results showed the highest radical-scavenging activity of anthocyanins isolated from one genotype of Cigančica cherry (genotype VN 10-11), Petrovaradinska and Oblačinska cherry cultivar. Integral antioxidative capacity was determined by luminometry (Photochem), calculating the ascorbic acid equivalents. The best reducing power was shown by anthocyanins isolated from Maraska and Petrovaradinska cherry cultivars. Peroxidase activity of fresh plant material was determined and the influence of anthocyanins on peroxidase activity was investigated

Biochemical and anatomical changes of spruce needles exposed to urban dust pollution

The effect of extensive urban dust pollution, caused mainly by road traffic, on some biochemical and structural characteristics of current-year Norway spruce (Picea abies L. Karst.) needles was investigated. Two categories of needle samples were formed according to the data about the pollution levels obtained from the Croatian National Institute of Public Health: less and more affected. Apoplastic guaiacol peroxidases were used as the molecular stress markers. Peroxidase activity was doubled in more affected needles compared with the less affected ones. Also, the electrophoretic pattern of samples extracted from more affected needles revealed the expression of additional isozyme band, which could be attributed to the activation of detoxifying mechanisms. Anatomy of more affected needles was changed as well. Necrosis of needle mesophyll usually connected with the stomata was the most outstanding character. Also, distortions of sieve cells were present in the same needle samples indicating possible disturbances in mineral nutrition. The obtained results showed that needles of Norway spruce trees that are exposed to the higher pollution level undergoes to both structural and biochemical changes. Besides of the described changes, the investigated spruce trees are able to survive in more polluted environment as well

Efficiency of the photosynthetic apparatus in developing needles of Norway spruce ( Picea abies L. Karst.)

The photosynthetic performance of developing spruce ( Picea abies L. Karst.) needles was investigated. As revealed by previous reports, the biosynthesis of chlorophylls and carotenoids was not following the characteristic chloroplast ultrastructure building up during needle elongation process. The aim of our study was to investigate photosynthetic capability (evaluated by oxygen evolution and chlorophyll a fluorescence kinetics measurements), the dynamics of chloroplast pigments biosynthesis and the expression of major photosynthetic proteins as well as to find out possible correlation between components of issue. Low amounts of chlorophylls and carotenoids, LHC II and Rubisco LSU were detected in the embryonic shoot of vegetative buds. Although PS II was functional, oxygen production was not sufficient to compensate for respiration in the same developmental stage. The light compensation point of respiration was successively lowered during the needle elongation. Nevertheless the significant increase in photosynthetic pigments as well as the high level of expression of LHC II and Rubisco LSU proteins was observed in the later stages of needle development. Our results suggest that, besides light, some other environmental factors could be critical for producing fully functional chloroplasts in rapidly growing young needles

Antioxidative activity of anthocyanins from sour cherries

The aim of this study was to examine antioxidant activities of the anthocyanins isolated from different sour cherry ( Prunus cerasus ) cultivars. DPPH radical method and photochemiluminescence detection method were employed. The effect of isolated anthocyanins on peroxidase activity was also investigated. In the DPPH method, methanol extract of isolated anthocyanins was employed and results showed the highest radical-scavenging activity of anthocyanins isolated from one genotype of Cigančica cherry (genotype VN 10–11), Petrovaradinska and Oblačinska cherry cultivar. Integral antioxidative capacity was determined by luminometry (Photochem), calculating the ascorbic acid equivalents. The best reducing power was shown by anthocyanins isolated from Maraska and Petrovaradinska cherry cultivars. Peroxidase activity of fresh plant material was determined and the influence of anthocyanins on peroxidase activity was investigated

PSII photochemistry in vegetative buds and needles of Norway spruce (Picea abies L. Karst.) probed by OJIP chlorophyll a fluorescence measurement

Vegetative buds represent developmental stage of Norway spruce (Picea abies L. Karst.) needles where chloroplast biogenesis and photosynthetic activity begin. We used the analyses of polyphasic chlorophyll a fluorescence rise (OJIP) to compare photosystem II (PSII) functioning in vegetative buds and fully photosynthetically active mature current-year needles. Considerably decreased performance index (PIABS) in vegetative buds compared to needles pointed to their low photosynthetic efficiency. Maximum quantum yield of PSII (Fv/Fm) in buds was slightly decreased but above limited value for functionality indicating that primary photochemistry of PSII is not holdback of vegetative buds photosynthetic activity. The most significant difference observed between investigated developmental stages was accumulation of reduced primary quinine acceptor of PSII (QA−) in vegetative buds, as a result of its limited re-oxidation by passing electrons to secondary quinone acceptor, QB. We suggest that reduced electron transfer from QA− to QB could be the major limiting factor of photosynthesis in vegetative buds