PHYSIOLOGICAL ACTIVITIES OF HELMINTHOSPOROL AND HELMINTHOSPORIC ACID: II. EFFECTS ON EXCISED PLANT PARTS

Effects of H-ol and H-acid were observed using excised partsof several plant species. Both H-ol and H-acid were active inelongation of oat coleoptile and mesocotyl, expansion of Raphanusleaf disk, but were inactive in elongation of wheat coleoptileand of green stem of pea. They gave also negative results inthe standard Avena curvature test and in the split pea test.In expansion of lettuce cotyledon, H-ol was inactive while H-acidwas active. In excised plant parts, as in intact plants, theactivity of H-ol and H-acid resembles rather gibberellins thanauxins and cytokinins. (Received August 20, 1966; )     

PROMOTING ACTIVITY OF TERPENIC LACTONES IN PHASEOLUS ROOTING AND THEIR REACTIVITY TOWARD CYSTEINE

Sesquiterpenoids which contain exomethylenes conjugated to -lactonecarbonyl-heliangine, helianginol, pyrethrosin and cyclopyrethrosinacetate—promoted the adventitious root formation on hypocotylsof cuttings taken from light-grown (1900 lux) 6-day old Phaseolusmungo seedlings, but their derivatives in which the methylene-lactone systems are reduced-to the saturated lactones—dihydroheliangine,hexahydro-heliangine, dihydrohelianginol, dihydrocyclopyrethrosinacetate and tetrahydrocyclopyrethrosin acetate—showedno effect on the root formation. As far as the present experiment is concerned, every substancewhich showed promoting activity in Phaseolus rooting reactedwith cysteine and formed an adduct, but any of the substancesincapable of promoting root formation did not react with cysteine.The correlation of promoting activity of terpenic lactones inPhaseolus rooting with their reactivity toward SH groups maythus be demonstrated. ¹ Contribution No. 14 from the Botanical Gardens, Faculty ofScience, University of Tokyo, Tokyo.     

Multiple Forms of Acid Phosphatase in Cotyledons of Vigna mungo Seedlings

Acid phosphatase from cotyledons of dark-grown Vigna mungo seedlingswas separated into four forms (la, Ib, Ha and lib) by ion-exchangercolumn chromatographies. Each form of the acid phosphatase wascharacterized for its pH dependency, substrate specificity,thermal stability, activation energy, approximate molecularweight, and the effect of metal ions and other substances onits activity. Each form of the enzyme exhibited high activitytowards ATP and ADP relative to their activity towards p-nitrophenylphosphate,but showed very low activity towards phytate, a major organicphosphate reserve in cotyledons. Among the four forms, lib wasmost distinguishable by its low molecular weight and the thermalenhancement of activity.     

Network analysis of potential migration routes for Oriental White Storks (<Emphasis Type="Italic">Ciconia boyciana</Emphasis>)

From 1998 through to 2000, we satellite-tracked the movements of 13 Oriental White Storks (Ciconia boyciana) on their autumnal migration in order to identify their important stopover sites for preserving links from the Russian Far East breeding sites to the wintering sites in south-eastern China. New analytical methods of satellite tracking data were employed to derive robust information on the locations of stay sites, the number of stopovers made during migration, and the distance traveled without making stopovers. Based on the derived information, we modeled a stay site network as an abstraction of the storks potential migration routes from their breeding sites to wintering sites. Using network analysis techniques, we explored how the loss of stopover sites could affect the connectivity of potential migration routes. The results suggested that if the seashore stopover sites facing Bohai Bay in eastern China were lost, the storks wintering sites along the Yangtze River in south-eastern China would be isolated. Among the seashore stopover sites, Jiantuozhi Gley Mire (39.185°N, 118.627°E), located on the northern seashore of Bohai Bay, was considered particularly important for migrating storks, because it was used every year by the storks we tracked. If conservation needs of this critically located site fail to be addressed, the stay site network of storks can create weak links in the chain of migration and, if broken, storks will have great difficulties in completing their autumnal migration.     

Accumulation of Trehalose as a Compatible Solute under Osmotic Stress in Euglena gracilis Z

ABSTRACT. The photosynthetic protozoon Euglena gracilis, accumulated a large amount of trehalose in the cells under salt or osmotic stresses. Radioactivity of [14C] paramylon, a β-1,3-polyglucan which was stored in the cells of E. gracilis. was degraded rapidly and this radioactivity was almost stoichiometrically incorporated into trehalose. The interconversion of trehalose from paramylon by salt or osmotic stresses was dependent on the concentrations or osmotic pressures, suggesting that E. gracilis accumulate trehalose as an osmoprotectant. After the removal of salt or osmotic stresses, trehalose was gradually degraded, however, it was not converted into paramylon.     

基于GET技术的混合厌氧发酵产甲烷研究

GET是一种国外新研发的在田间利用秸秆进行甲烷生产的技术。为了推动该技术在我国的实际应用,本研究以稻草与牛粪为发酵原料,水稻田土壤作为基底,采用正交试验法,测试了温度、发酵基质配比（稻草∶牛粪）和秸秆腐熟剂浓度对混合厌氧发酵产气量的影响。结果表明：各处理因子的产气动态呈“S”型增长模式,但在快速增长时间和增长幅度上有一定区别。30 ℃和40 ℃处理的累积产气量显著高于10 ℃和20 ℃处理的累积产气量;发酵基质配比以1∶1处理的累积产气量最大,分别比1∶0（对照）、1∶2和1∶3配比高34.12%、20.39%和21.78%;秸秆腐熟剂浓度的产气效果在实验范围内随着浓度的增加而增加。厌氧发酵过程中各实验因子下挥发性脂肪酸（VFAs）含量和pH在20 d左右分别有一个高峰和低谷值且都有较大差异,各因子主要是通过在这个时期对厌氧发酵进程的影响而对整个产气量产生影响。综合分析显示稻草厌氧发酵产生物甲烷的最优组合为：温度30 ℃、发酵基质配比1∶1、秸秆腐熟剂浓度8%。     

Species Specificity of the Insect Prothoracicotropic Hormone (PITH): the Presence of Bombyx-and Samia-Specific PTTHs in the Brain of Bombyx mori

Crude extracts of Bombyx mori brains can provoke adult development when injected into brain-removed dormant pupae of Bombyx mori and Samia Cynthia ricini. From this fact the prothoracicotropic hormone (PTTH) of Bombyx has long been thought to be species-nonspecifically active on Samia. Chemical fractionation of Bombyx brain or head extracts by fractional precipitation with acetone, Sephadex G-50 gel-filtration, and DEAE-Sepharose CL-6B chromatography, however, separated the fractions which activated Bombyx brainless pupae from those which activated Samia. Those results reveal the existence of two species-specific PTTHs.     

The land–atmosphere water flux in the tropics

Tropical vegetation is a major source of global land surface evapotranspiration, and can thus play a major role in global hydrological cycles and global atmospheric circulation. Accurate prediction of tropical evapotranspiration is critical to our understanding of these processes under changing climate. We examined the controls on evapotranspiration in tropical vegetation at 21 pan-tropical eddy covariance sites, conducted a comprehensive and systematic evaluation of 13 evapotranspiration models at these sites, and assessed the ability to scale up model estimates of evapotranspiration for the test region of Amazonia. Net radiation was the strongest determinant of evapotranspiration (mean evaporative fraction was 0.72) and explained 87% of the variance in monthly evapotranspiration across the sites. Vapor pressure deficit was the strongest residual predictor (14%), followed by normalized difference vegetation index (9%), precipitation (6%) and wind speed (4%). The radiation-based evapotranspiration models performed best overall for three reasons: (1) the vegetation was largely decoupled from atmospheric turbulent transfer (calculated from Ω decoupling factor), especially at the wetter sites; (2) the resistance-based models were hindered by difficulty in consistently characterizing canopy (and stomatal) resistance in the highly diverse vegetation; (3) the temperature-based models inadequately captured the variability in tropical evapotranspiration. We evaluated the potential to predict regional evapotranspiration for one test region: Amazonia. We estimated an Amazonia-wide evapotranspiration of 1370 mm yr⁻¹, but this value is dependent on assumptions about energy balance closure for the tropical eddy covariance sites; a lower value (1096 mm yr⁻¹) is considered in discussion on the use of flux data to validate and interpolate models.