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 ...

Field studies were conducted to determine the potential for alterations in physiology and the intraspecific variation in sensitivity of 20 wheat (Triticum aestivum) cultivars to enhanced ultraviolet-B (UV-B, 280-315 nm) radiation. The supplemental UV-B radiation was 5 kJ m(-2), simulating a depletion of 20% stratospheric ozone. Out of 20 wheat cultivars (from South China, North China and Mexico...

The effects of irrigation water salinity on growth, chlorophyll contents, proline and nutrients accumulation and K/Na ratio in three walnut cultivars was investigated. Three irrigation water salinity levels with electrical conductivities of 1,5, 3, and 5.0 dS/m and tap water as a control treatment were used in a randomized design with four replications. Irrigation practices were realized by con...

Photosynthetic effects of the leaves extracts from Ipomoea cairica on Parthenium hysterophorus L were studied. Ipomoea cairica dried leaf powder (20g) was dissolved in distilled water (200ml) for foliar application. The seedlings were maintained under natural condition in Insect free net house. The experiment was carried out to analyze the effects of Ipomoea cairica leaves extract by measuring ...

and an increased chlorophyll b to chlorophyll a ratio for better light capture in low light. Furthermore, an Ostreobium strain living in a coral skeleton, where nearly all of the red light has been captured by the zooxanthellae in the coral tissue, has been shown to have modified chlorophyll with a spectrum shifted towards far-red wavelengths. As zooxanthellae cannot use far-red light, more of ...