The oligomeric state of photosystem 2 (PS2) complex in soybean leaves treated with saturating irradiance was studied by non-denaturing polyacrylamide gel electrophoresis (PAGE) and gel filtration chromatography. PS2 dimers resolved by non-denaturing PAGE accounted for about 75 % of total PS2 complex and there was no significant difference in the ratio of PS2 dimer to monomer between samples from saturating irradiance-treated and fully dark-adapted leaves. Furthermore, BBY particles were resolved into four chlorophyll-enriched fractions by gel filtration chromatography. From their molecular masses and protein components, these fractions were deduced to be PS2 dimer, PS2 monomer, oligomeric light-harvesting complex 2 (LHC2), and monomeric LHC2. Also, no change in the proportion of PS2 dimer in total PS2 was observed in the granal region of thylakoid membranes from soybean leaves after saturating irradiation. Hence the dimer is the predominant natural form of PS2 in vivo and no monomerisation of PS2 dimer occurs during saturating irradiance-induced photoinhibition in soybean leaves. and Shi-Qing Cai ... [et al.].
Count von Manderscheid-Blankenheim´s library at Blankenheim Castle was closed after Napoleon´s army invaded the Rhineland in 1794. The last owner of the castle, Augusta and Filip Krisitan von Sterrnberg-Manderscheid took some of the books to Prague where they became parts of the Sternberg Library, which itself was incorporated into Prince Lobkowicz´s library, with which it was transferred in 1928 to the Czech National Library collection. This study provides information on the discovery of the uniquely preserved catalogue of the Blankenheim Castle library, compiled sometime between 1789 and 1794. It has been used to successfully identify a total of 29 manuscripts in the National Library collection. The study concludes with an edition of the Blankenheim manuscript catalogue and brief descriptions of the discovered codices.
The mangroves Rhizophora lamarkii, Ceriops roxburghiana, Bruguiera gymnorrhiza, Aegiceras corniculatum, and Lumnitzera racemosa were screened for their carbon metabolic pathways by measuring net photosynthetic rate (PN), 13C discrimination rate, leaf anatomy, titratable acidity, and activities of phosphoenolpyruvate carboxylase, NADH-malate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, and pyruvate phosphate dikinase. The tested mangroves had a well developed succulence, opening of stomata during day time and closure in the night hours, and absence of diurnal fluctuation of organic acids in their leaves which excludes the possibility of these species being CAM plants. Moreover, the leaf anatomy had not exhibited Kranz syndrome. The high values of discrimination against 13C, low PN, high CO2 compensation concentration, and the activities of aminotransferases in the direction of alanine formation suggest that the species may follow C3 mode of carbon metabolic pathway. and V. Venkatesalu ... [et al.].
Net photosynthetic (P^) and transpiration (£) rates and stomatal conductance (gj) were determined in cotton genotypes under drought during the growth cycle. A decrease in P^, E and gs was observed as soil water availability diminished. appeared dosely related to stomatal apertuře at low g^ levels. However, intercellular CO2 concentration was not so much affected by stomatal closure. An important inter- and intra-genotypic variation in g^ was found at the initial sampling dates. Inter-genotypic variation for increased with time, probably as a result of a higher capacity for water uptake in some genotypes.