The activity of ribulose 1,5-diphosphate (RuDP)-carboxylase and RuDP-oxygenase was measured in crude leaf extracts of the tobacco (N . tabacum ) phenotypes which differed with respect to their gene constitution and with respect to their photosynthetic and photorespiratory activity. The green wild type (JWB) which carried the discussed two nuclear factors su and aur in the condition su/su Aur/Au...

basil plants (ocimum basilicum l.) were sprayed with salicylic acid (1mm) and exposed to ultraviolet-c (uv-c) radiation (40 wm-2) after emergence of six developed leaves. plants were grown for 18 days and exposed to uv-c for 5 mind-1 alternatively. chlorophyll a, chlorophyll b and carotenoide were considered for analysis of photosynthetic pigments. the results showed that the photosynthetic pig...

Inhibitor experiments indicate that photosynthetic electron transport is required for light activation of the pea (Pisum sativum) leaf chloroplast enzymes NADP-linked glyceraldehyde-3-phosphate dehydrogenase, NADP-linked malic dehydrogenase, ribulose-5-phosphate kinase and sedoheptulose-1,7-diphosphate phosphatase, and for inactivation of glucose-6-phosphate dehydrogenase. Modulation of the act...

The response of net photosynthetic CO(2) uptake (A) to increasing leaf intercellular CO(2) concentration (c(i)) was determined in antisense Nicotiana tabacum plants, derived from six independent transformation lines, displaying a range of sedoheptulose-1, 7-bisphosphatase (SBPase) activities. The maximum in vivo ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation (V(c,max)) ...

Arylethanediamines, Photophosphorylation, Uncouplers, Structure-Activity Relationships The effects of the algicide PH 40-62 on photosynthetic reactions in spinach chloroplasts were studied. The compound proved to be an uncoupler of photophosphorylation, whereas inhibition of photosynthetic electron transport occurred at higher concentrations. The site of this inhibition was before photosystem I...

In this study, a series of twelve ring-substituted salicylanilides and carbamoylphenylcarbamates were prepared and characterized. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Moreover, their site of action in the photos...

Improvements to leaf photosynthetic rates of crops can be achieved by targeted manipulation of individual component processes, such as the activity and properties of RuBisCO or photoprotection. This study shows that simple forward genetic screens of mutant populations can also be used to rapidly generate photosynthesis variants that are useful for breeding. Increasing leaf vein density (concent...

Photosynthetic algae and cyanobacteria have been proposed for producing biofuels through a direct photoconversion process. To accelerate the efforts of discovering and screening microbes for biofuel production, sensitive and high throughput methods to measure photosynthetic activity need to be developed. Here we report the development of new ratiometric optical oxygen and pH dual sensors with t...

Plants display a remarkable diversity of thioredoxins (Trxs), reductases controlling the thiol redox status of proteins. The physiological function of many of them remains elusive, particularly for plastidial Trxs f and m, which are presumed based on biochemical data to regulate photosynthetic reactions and carbon metabolism. Recent reports revealed that Trxs f and m participate in vivo in the ...

The expression of many genes of facultatively photosynthetic bacteria of the genus Rhodobacter is controlled by the oxygen tension. Among these are the genes of the puf and puc operons, which encode proteins of the photosynthetic apparatus. Previous results revealed that thioredoxins are involved in the regulated expression of these operons, but it remained unsolved as to the mechanisms by whic...