Changes in the functional organization of chlorophyll occur during light-dependent chlorophyll accumulation in yellow mutants of Chlamydomonas reinhardti£ These changes were studied using single-photon counting techniques to determine the chlorophyll fluorescence decay kinetics at various times after transfer of de-greened cultures to the light. Several different yellow mutants were analyzed: y...

The effects of UV-B radiation on the amount of chlorophyll a, b, carotenoids, flavonoids, anthocyanins, and polyphenols of three soybean cultivars was studied. After germination in the incubator, plants were put in pots of soil and during 3 weeks and irrigated with Hoagland solution every day. After 3 weeks, plants were exposed to UV-B for 20 min every day for a week. In each cultivar, UV-B red...

In order to study the effects of humic acid foliar spraying on morphological traits, photosynthetic pigmentation, and essential oil content of Dracocephalum moldavica, a factorial experiment was conducted based on a randomized complete block design with three replications in Saveh. The investigated factors included the use of humic acid at four levels 0 (control), 200, 400, and 800 mg/L and eth...

Higher plants acclimate to various light environments by changing the antenna size of a light-harvesting photosystem. The antenna size of a photosystem is partly determined by the amount of chlorophyll b in the light-harvesting complexes. Chlorophyllide a oxygenase (CAO) converts chlorophyll a to chlorophyll b in a two-step oxygenation reaction. In our previous study, we demonstrated that the c...

Chlorophyll b is synthesized from chlorophyll a and is found in the light-harvesting complexes of prochlorophytes, green algae, and both nonvascular and vascular plants. We have used conserved motifs from the chlorophyll a oxygenase (CAO) gene from Chlamydomonas reinhardtii to isolate a homologue from Arabidopsis thaliana. This gene, AtCAO, is mutated in both leaky and null chlorina1 alleles, a...

Chlorophyll-deficient individuals have been reported in most species of plants studied intensively by genetic methods. The majority of these chlorotic types have been shown to be the expression of a single gene mutation. However, there is a large group of types that exhibit maternal inheritance, and transmission of the deficiency to their offspring is conditioned by the cytoplasm. Until rather ...

In our work we were interested in the toxicity of fluorine on various parameters stress: chlorophyll, proteins, and antioxidant system lichen Xanthoria parietina (L.) Th. Fr., for this purpose, thalli treated by sodium fluoride (NaF) at concentrations 0, 0.5, 1.0, 5.0 10.0 mM, time scale 24, 48 96 h. The analysis results obtained revealed that all evaluated showed significant variations compare...