The dispersal potential of crown-of-thorns starfish (CoTS) larvae is important in understanding both the initiation and spread of population outbreaks, and is fundamentally dependent upon how long larvae can persist while still retaining the capacity to settle. This study quantified variation in larval survivorship and settlement rates for CoTS maintained at three different chlorophyll concentr...

Chlorophyll is a central player in harvesting light energy for photosynthesis, yet the rate-limiting steps of chlorophyll catabolism and the regulation of the catabolic enzymes remain unresolved. To study the role and regulation of chlorophyllase (Chlase), the first enzyme of the chlorophyll catabolic pathway, we expressed precursor and mature versions of citrus (Citrus sinensis) Chlase in two ...

Leaves of rye seedlings (Secale cereale L.) grown in the presence of four chlorosis-inducing herbicides under a low light intensity of 10 lux formed chlorophyll. When segments of such dim-light-grown leaves were exposed to 30,000 lux at either 0 degrees C or 30 degrees C, treatments with aminotriazole or haloxidine (group 1) showed no or only minor changes of their chlorophyll contents. In trea...

to comparison the photosynthetic parameters and leaf chlorophyll content and fluorescence of safflower (carthamus tinctorios l.) cultivars under salinity stress, a pot experiment was carried out as factorial based on completely randomized design with three replications in summer 2011 in university of yasouj. first factor included four salinity levels (zero, 75, 150 and 225 mm (formed as 20 to 1...

Plants need to allocate some of their limited resources for defense against herbivores as well as for growth and reproduction. However, the priority of resource allocation within plants has not been investigated. We hypothesized that plants with extrafloral nectaries (EFNs) invest more chlorophyll around their EFNs-to support a high rate of carbon fixation there-than in other leaf parts of youn...

Light dependent (35 Klux) chlorophyll bleaching in autotrophically grown Euglena gracilis cells at slightly acidic pH (6.5-5.4) is stimulated by the photosystem II blockers DCMU and DBMIB (both 10(-5) M) as well as by the autooxidizable photosystem I electron acceptor, paraquat (10(-3) M). Chlorophyll photobleaching is accompanied by the formation of thiobarbituric acid -- sensitive material ("...

Evidence for the self-aggregation of 10(S)-chlorophyll a (= chlorophyll a') in nonpolar solvents has been obtained by means of absorption spectroscopy in the visible and infrared regions. The visible absorption spectrum of chlorophyll a' exhibits a shoulder at 680 nm in aliphatic hydrocar­ bon solvents and the infrared spectrum measured in carbon tetrachloride contains an “aggrega­ tion peak” a...

Chlorophylls have been extensively investigated both experimentally and theoretically owing to the fact that they are essential for photosynthesis. In the reported study, two forms of chlorophyll, chlorophyll a and chlorophyll b, were investigated by means of the density functional theory. Optimization of the S0, S1 and T1 states was performed with the B3-LYP functional. The computed fluorescen...

Barley leaves grown under a natural light/dark regime have a chlorophyll content of 1300 [ig/g fresh weight and a chlorophyll a /b ratio of 2 .5 -3 . When the plants are grown under cycles of 2 min light/118 min dark, the respective values are 50 and 5 — 9. With chloroplasts with low chlo­ rophyll b content variable fluorescence is depressed by about 30% by MgCl2; with those of high chlorophyll...

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...