The article deals with manuscript XIII G 25 of the National Library of the Czech Republic, which contains an explanation of part of the Book of Psalms (109-118). The explanation is attributed to the Master of the Prague University and preacher in the Prague Bethlehem Chapel Václav of Dráchov (about 1395-1469). The author analyses the contents of the codex, the relationship between it and further manuscripts, its provenience and finally, the research results in this field are summarized.
The article deals with manuscript XIII G 25 of the National Library of the Czech Republic, which contains an explanation of part of the Book of Psalms (109-118). The explanation is attributed to the Master of the Prague University and preacher in the Prague Bethlehem Chapel Václav of Dráchov (about 1395-1469). The author analyses the contents of the codex, the relationship between it and further manuscripts, its provenience and finally, the research results in this field are summarized.
In plants, hydrogen peroxide (H2O2) acts as a signalling molecule that facilitates various biochemical and physiological processes. H2O2 is a versatile molecule, involved in several cellular processes both under stress and stress-free conditions. In regulating plant metabolism under stress conditions, exogenous application of H2O2 also plays a pivotal role which is manifested in improved growth, photosynthetic capacity, and antioxidant protection. Abiotic stress is an inevitable environmental factor that extensively affects and reduces growth, quality, yield, and productivity of plants. Several signalling pathways involved in H2O2-mediated stress and defense responses have been extensively studied and there is ample scope of additional research that could further clarify the mechanism and modulating factors which regulate these pathways. An attempt has been made to dissect the role of H2O2 under low temperature stress and how it affects plant growth and development, photosynthetic capacity, regulation of antioxidant system, and signalling., T. A. Khan, M. Yusuf, Q. Fariduddin., and Obsahuje bibliografii
Hypobaria (low total atmospheric pressure) is essential in sustainable, energy-efficient plant production systems for long-term space exploration and human habitation on the Moon and Mars. There are also critical engineering, safety, and materials handling advantages of growing plants under hypobaria, including reduced atmospheric leakage from extraterrestrial base environments. The potential for producing crops under hypobaria and manipulating hypoxia (low oxygen stress) to increase health-promoting bioactive compounds is not well characterized. Here we showed that hypobaric-grown lettuce plants (25 kPa ≈ 25% of normal pressure) exposed to hypoxia (6 kPa pO2 ≈ 29% of normal pO2) during the final 3 d of the production cycle had enhanced antioxidant activity, increased synthesis of anthocyananins, phenolics, and carotenoids without reduction of photosynthesis or plant biomass. Net photosynthetic rate (PN) was not affected by total pressure. However, 10 d of hypoxia reduced PN, dark respiration rate (RD),
PN/RD ratio, and plant biomass. Growing plants under hypobaria and manipulating hypoxia during crop production to enhance health-promoting bioactive compounds is important for the health and well-being of astronauts exposed to space radiation and other stresses during long-term habitation. and C. He ... [et al.].
Phosphoenolpyruvate carboxylase isolated from Panicům maximum Jacq. leaf presented a hysteretic behaviour that resulted in a kinetical lag in the reaction progress curve. This lag depended on the concentration of etuiyme, total phosphoenolpyruvate (PEP) and total Mg2+. Through an analysis of these dependences it is suggested that the hysteresis is due to an association-dissociation process influenced by union, to one form of the enzyme, of more than one of the three possible ligands; free Mg2+, free PEP or PEP-Mg2+ complex. The partially purified enzyme showed, during steady statě, a Michaelis-Menten kinetics for PEP and Mg2+ (total concentrations) and pH optima between 7.8 and 8.2.
Dendrobium is one of the three largest genera in the Orchidaceae and is distributed throughout various habitats. We investigated photosynthesis in seven Dendrobium species and cultivars by comparing their leaf δ13C values, titratable acidity, and CO2 exchange in well-watered and drought-stressed conditions. In addition, the leaf thickness and mesophyll succulence index (Sm) were measured in well-watered conditions. Our results indicate that Dendrobium loddigesii is a typical obligate (or constitutive) CAM plant because the leaf δ13C values were -14.47 and -14.66‰ in both conditions, respectively. Others showed the leaf thickness of 0.31-0.89 mm and their δ13C values ranged from -25.68 to -28.37‰. These are not the CAM plants but they could not be classified as obligate C3 or C3/CAM intermediate plants. Dendrobium crepidatum and Dendrobium fimbriatum were further identified as the obligate C3 plants because the net CO2 uptake was positive during daytime and negative during nighttime in both conditions. In contrast, Dendrobium chrysotoxum, Dendrobium nobile, and D. nobile ‘V1’ and ‘V4’, showed no positive net CO2 uptake and low ΔH+ values during nighttime under well-watered conditions, indicating C3 photosynthesis. However, they showed the positive net CO2 uptake and large ΔH+ values during nighttime after drought-stress (21 or 28 days without H2O), indicating CAM photosynthesis. Therefore, these four species and cultivars were identified as C3/CAM intermediate (inducible or facultative) plants. In brief, obligate CAM, C3/CAM intermediate, and obligate C3 plant types all exist in the section of Dendrobium. To the best of our knowledge, this is the first report of the obligate C3 plants in Dendrobium, and these diverse photosynthetic pathways may explain their varied environmental adaptations., S. Qiu, S. Sultana, Z. D. Liu, L. Y. Yin, C. Y. Wang., and Obsahuje bibliografii
Quantification of chlorophyll (Chl) fluorescence is a versatile tool for analysing the photosynthetic performance of plants in a non-intrusive manner. A pulse-amplitude modulated fluorometer was combined with a CNC router for the automated measurement of the effective quantum yield of photosystem 2 (Φ2) of Arabidopsis thaliana plants. About 90 000 individual plants representing 7 500 lines derived from En-transposon and T-DNA mutagenised Arabidopsis populations were screened for mutants with altered Φ2. Forty-eight recessive Φ2 mutations were identified of which most exhibit also altered pigmentation and increased photosensitivity. For three Φ2 mutants the corresponding mutated genes were identified that code all for chloroplast-located proteins. Comparison of the Φ2 mutant screen with other screening methods based on the measurement of Chl fluorescence shows that the Φ2 mutants identified are different to mutants identified by high Chl fluorescence. Some Φ2 mutants, on the contrary, are common to mutants identified by screens based on non-photochemical quenching. and C. Varotto ... [et al.].
The illuminated manuscripts in Zittau are only known to some extent. The two-volume Vesperale and Matutinale (A I, A VI) from the second decade of the fifteenth century was created for the Karlov Augustinian Monastery in Prague. The painted decoration is the work of the Master of the Hasenburg Missal, who represents the highest stage of fine style. The Missal of the Prague Diocese (A VII) is from the early fifteenth century. The decoration is the work of two illuminators, led by the Master of the Roudnice Psalter, although the share of the second illuminator - the Master of Paul's Gospel – is more extensive. Hitherto unknown is the Antiphonary (A IV) from the second decade of the fifteenth century. The small share of the primary illuminator is based on the Master of the Antwerp Bible. The Zittau Gradual (A III) is dated 1512; its primary illuminator was Janíček Zmilelý of Písek. The Gradual (A V) was created in 1435 for the parish church in Zittau by commander of the Commenda of Johannites Johann Gottfried von Goldbergu. The decoration was evidently created in Vratislav by the Master of the Bible of Banken. The Vesperal and Matutinal (A II) from the end of the fifteenth century was perhaps designated for the Commenda of Johannites in Zittau. The decoration is Saxon work.
The illuminated manuscripts in Zittau are only known to some extent. The two-volume Vesperale and Matutinale (A I, A VI) from the second decade of the fifteenth century was created for the Karlov Augustinian Monastery in Prague. The painted decoration is the work of the Master of the Hasenburg Missal, who represents the highest stage of fine style. The Missal of the Prague Diocese (A VII) is from the early fifteenth century. The decoration is the work of two illuminators, led by the Master of the Roudnice Psalter, although the share of the second illuminator - the Master of Paul's Gospel – is more extensive. Hitherto unknown is the Antiphonary (A IV) from the second decade of the fifteenth century. The small share of the primary illuminator is based on the Master of the Antwerp Bible. The Zittau Gradual (A III) is dated 1512; its primary illuminator was Janíček Zmilelý of Písek. The Gradual (A V) was created in 1435 for the parish church in Zittau by commander of the Commenda of Johannites Johann Gottfried von Goldbergu. The decoration was evidently created in Vratislav by the Master of the Bible of Banken. The Vesperal and Matutinal (A II) from the end of the fifteenth century was perhaps designated for the Commenda of Johannites in Zittau. The decoration is Saxon work.
The Municipal Library in Bautzen houses a lot of Czech manuscripts which are dealt with by special literature, but the illuminations of which are known very scarcely. The decoration of the collection of work by Jan Hus (Ms. fol. 51) can be narrowed to the middle of the 15th century; the present date of 1412 is based on an entry in fol. 137v and is untenable because it is the text, not the decoration which came into existence in this year. The depictions – the figural and the heraldic ones – were added to the manuscripts supplementally; it is probably a picture of Jan Hus mounting the pulpit and a coat of arms of a member of the Hroznata family, maybe of the Kladruby abbot Bušek of Vrtba or of the front warrior of the Catholic Side, Burian of Gutštejn. The collection of theological-juridical texts (Ms. fol. 56) contains moreover yearly records; only one text item (Řeči besední) can be attributed to Tomáš Štítný of Štítné. The decoration of the codex is limited only to one fi gural illumination and one ornamental initial. Its style is quite advanced; it can most likely be dated to the 1470s.