Screening by chlorophyll (Chl) affects photoconversion rates and photoequilibrium ratios of phytochrome in vivo and may cause distortion of the action spectra of photomorphogenesis (N Kazarinova-Fukshansky, M Seyfried, E Schifer 1985 Photochem Photobiol 41: 689-702 of seedlings have been used in photomorphogenesis research to decrease the effects of Chl screening on the state of phytochrome and to allow spectrophotometric assays of phytochrome in vivo in light-grown seedlings (1, 4, 5). We also wanted to check if a specific inhibitor action on the photoresponse studied might affect the interpretation of the results in terms of the expected differences between the states of phytochrome in Chl-rich and Chl-poor seedlings (6). We measured anthocyanin production under R, FR, and simultaneous R + FR irradiations in young, water-grown and STM-treated cabbage seedlings. Streptomycin inhibits chloroplast development and Chl synthesis and enhances anthocyanin production in young cabbage seedlings (9). We used STM instead of Norflurazon, a more commonly used 'Chl-bleacher' (1, 4, 5), because the differences in the Chl levels of seedlings exposed to prolonged irradiations with different spectral regions are less pronounced in STM-treated than in Norflurazon-treated seedlings (7). MATERIALS AND METHODSPlant Material. Seeds of two lots (D and F) of cabbage (Brassica oleracea L., cv Red Acre; W. A. Burpee Co.) were sown in Petri dishes (30 seeds/dish) on filter paper (Eaton-Dikeman No. 923-70) moistened with distilled water or with a solution of STM (200 ,ug/ml). This concentration of STM was chosen on the basis of dose-response curves; it produces about 90% reduction in Chl content without any effect on respiration (9; and additional data not shown). The dishes were wrapped in black cloth and incubated in darkness for 72 h at 20 to 21°C.Light Treatments. The light treatments were started 72 h after sowing and were given in two growth chambers

Community knowledge of ischaemic stroke needs to be enhanced so that individuals present earlier, leading to timely management.

No abstract

No abstract

No abstract