SPECIFIC RNA FROM PHOTOPERIODICALLY INDUCED COTYLEDONS OF PHARBITIS NIL

The nucleotide ratio of several RNA species from cotyledonsof Pharbitis nil subjected to a single 16 hr night with or withouta 15 min light-break, or to continuous light was investigated.RNA species examined were RNAs from nuclear, mitochondrial,microsomal, and supernatant fractions separated by differentialcentrifugation, and s-, r-, and m-RNAs fractionated by methylatedalbumin column chromatography. Of the RNAs examined, m-RNA alone was found to change its nucleotideratio with photoperiod applied. Thus as compared with m-RNAfrom non-induced cotyledons (exposed to continuous light oran interrupted night), m-RNA from cotyledons induced by an uninterruptednight contained significantly reduced guanylic and cytidylicacids on molar ratio basis. A working hypothesis was proposed that floral stimulus productionin cotyledons may be directed by gene DNA derepressed photoperiodically. (Received October 18, 1966; )     

Meconopsis wilsonii subsp. wilsonii (Papaveraceae) Rediscovered

Field studies in the Lamagetou Nature Reserve , Mianning Xian , Sichuan Province , in the summer of 2005 revealed a particularly rich and diverse flora . One particularly noteworthy plant growing in openings in the forest, at woodland margins and on exposed slopes, was the recently described Meconopsis wilsonii Grey-Wilson subsp. wilsonii (Papaveraceae) , a species previously known only from the type collection and last collected in 1908 , nearly 100 years ago.     

Glutaraldehyde as an effective stabilizer for the isolation of intact chloroplasts

A good yield of structurally intact chloroplasts isolated fromwheat for electron microscope examination was obtained withthe application of glutaraldehyde fixative as a primary maceratingand isolating medium. It was not always necessary to take specialprecautions in tonicity or to hesitate to store the chloroplastsuspension for delayed electron microscopic preparation. Somenoticeable features found in senescent chloroplasts are described. ¹This work is a part of a project aided by a fellowship grantedto the author from the National Research Council of Canada,1963–1965. ²Permanent address: Department of Biology, Faculty of Science,Niigata University, Niigata, Japan. (Received January 23, 1969; )     

Formation of putrescine from ornithine and arginine in tobacco plants

Putrescine was formed when both DL-ornithine-2-¹⁴C and L-arginine-U-¹⁴Cwere injected into tobacco plants. The incorporation rate ofthese amino acids into putrescine was higher in potassium orsulfur deficient plants than in normal plants. Degradation ofputrescine-1,4-¹⁴C injected into tobacco plants was inhibitedby a potassium or sulfur deficiency. Increased accumulationof putrescine in potassium or sulfur deficient plants may bepartly dependent upon this inhibition in the degradation ofputrescine. Detached leaves and roots were also able to formputrescine from DL-ornithine-2-¹⁴C and L-arginine-U-¹⁴C. (Received December 13, 1968; )     

EFFECT OF PAPAIN-DIGESTED, UNIVALENT ANTIBODY AGAINST SPERM-BINDING FACTOR ON THE FERTILIZABILITY OF SEA URCHIN EGGS

Papain-digested, anti-sperm-binding factor serum which has only a species-specific antibody, deprives the egg of fertilizability as well as does undigested serum. This effect is shown to be exerted by direct masking of species-specific sperm-binding sites on the vitelline layer by univalent antibodies.     

Morphological and anatomical analyses of rheophytic Rhododendron ripense Makino (Ericaceae)

The comparative morphology and anatomy of the leaves of the rheophytic Rhododendron ripense and the closely related inland species Rhododendron macrosepalum were examined. The leaf of R. ripense is thinner than that of R. macrosepalum, with leaf length to width ratios (leaf index) of 2.92 and 1.91, respectively. Moreover, the leaf of R. ripense consists of fewer cells than the leaf of R. macrosepalum, suggesting stenophyllization of R. ripense caused by the decreased number of cells. In addition, leaf thickness and the number of stomata per leaf of R. ripense were significantly greater than those of R. macrosepalum, but the density of the short glandular pilose hairs on the leaf of R. ripense was lower. The observed morphological differences between the two species may be explained by certain aspects of the riparian environment, such as high irradiation and frequent flooding after heavy rainfall, to which R. ripense is exposed.     

Electron transport dependent adenosine triphosphatase activity in castor bean endosperm mitochondria

The release of inorganic phosphate from ATP by mitochondriaisolated from endosperms of castor bean (Ricinus communis) wasstimulated by Mg⁺⁺, but not by Ca⁺⁺. EDTA, succinate, NADH₂or oligomycin depressed the reaction. The depression by succinatewas removed by KCN, antimycin A or anoxia. DNP alone did notaffect activity but did stimulate the Pi release in the presenceof succinate under aerobic conditions. Enhanced Pi release inthe presence of succinate and DNP was cancelled by KCN, antimycinA, oligomycin or anoxia. On the basis of these results, themechanism of ATPase action in castor bean endosperm mitochondriais discussed. (Received January 27, 1969; )