滇蜀豹子花核型及其变异研究

本文详细报道了滇蜀豹子花的核型,发现居群中存在两种细胞型,即A型和B型。A型参考核型为2n = 24＝2m(2SAT)+2sm+8st(4SAT)+12t(2SAT),其第3号两条同源染色体长臂均无居间随体：B型参考核型为2n=24＝2m(2SAT)+2sm+8st(2SAT)+12t(3SAT)+0—1b,其第3号一条同源染色体长臂紧靠着丝点处有一大而明显的居间随体,而另一条同源染色体则无,构成明显的3号染色体的结构杂合性。统计表明,居群中二者的比例近似为1A;2B。研究还发现了大量的体细胞染色体结构变异核型,表明滇蜀豹子花核型尚未趋于稳定,还处于强烈分化之中,高频率的体细胞染色体结构变异是其种内分化不可忽视的一种进化要素。     

生态环境对川芎产、质量的影响

生态环境对川芎产、质量的影响丁德蓉,陈兴福,卢进,黄文秀,刘岁荣（四川省中医药研究院药物种植研究所,南川６４８４０８）ＩｎｆｌｕｅｎｃｅｏｆＥｃｏｅｎｖｉｒｏｎｍｅｎｔｏｎｔｈｅＹｉｅｌｄａｎｄＱｕａｌｉｔｙｏｆＬｉｇｕｓｔｉｃｕｍｃｈｕａｎｘｉｏｎ...     

触珠蛋白研究进展

触珠蛋白是一种酸性糖蛋白,属急性期反应蛋白之一,由于所含轻链类型的不同,触珠蛋白具有遗传多态性,触珠蛋白的合成和降解主要在肝脏进行,并受细胞因子、前列腺素、激素等的调节,触珠蛋白具有广泛的生物学功能,可能是一种重要的调节蛋白.     

“8455”小麦植株化学成分与麦蚜（长管蚜、二叉蚜）种群消长的关系

通过对两种肥力条件下的“8455”小麦植株化学成分与麦长管蚜和麦二叉蚜种群消长关系的研究与分析,结果表明可溶性糖、含钾量、含水量是影响麦二叉蚜种群消长的主要因子,胱氨酸是影响麦长管蚜种群消长的主要因子。     

Effects of aluminium on growth and cation uptake in seedlings of Eucalyptus mannifera and Pinus radiata

This experiment was designed to examine the effects of aluminium (Al) on the growth of Pinus radiata (D. Don) and Eucalyptus mannifera subsp. mannifera (Mudie) seedlings in culture solutions in a glasshouse to help explain the failure of radiata pine trees on some acid, low fertility soils in Australia on which the native eucalypts flourish. Aluminium (Al) in culture solution increased the growth of roots and shoots of seedlings of both species but while growth of the eucalypt continued to increase with increases in Al to 2.222 μM, growth of the pine was largest at 370 μM Al. In addition to total root length, specific root length (length per unit dry weight), a measure of fineness of the root, increased in the eucalypt seedlings as the substrate Al increased. Growth of the shoots and roots of the pine in the absence of any added Al was extremely poor suggesting that Al, in low concentrations, may be an essential element or ameliorate some other factors in solution culture at low pH. Root and shoot concentrations of K increased with increasing Al, whilst Ca and Mg Concentrations decreased and Mn concentrations were unaffected in both species. Tissue Ca and Mg concentrations were 2 to 3 times higher in the eucalypt seedlings than the pine at all levels of added Al due to greater uptake of these elements by the eucalypt. In contrast, at the highest concentration of Al in the medium, shoot Al concentrations were lower in the cucalypt than in the pine due to a greater proportion of Al being retained in the eucalypt roots. These differences between the seedlings in terms of root growth and tissue cation concentrations may help explain the ability of eucalypt species to maintain vigorous growth on acid soils high in Al and low in Ca and P, where growth of the pines failed.     

Salicylic acid inhibits the biosynthesis of ethylene in detached rice leaves

The effects of salicylic acid (SA) on ethylene biosynthesis in detached rice leaves were investigated. SA at pH 3.5 effectively inhibited ethylene production within 2 h of its application. It inhibited the conversion of ACC to ethylene, but did not affect the levels of ACC and conjugated ACC. Thus, the inhibitory effect of SA resulted from the inhibition of both synthesis of ACC and the conversion of ACC to ethylene.Abbreviations ACC 1-aminocyclopropane-1-carboxylic acid - EFE ethylene-forming enzyme - SA salicylic acid     

Divalent cation and lipid-protein interactions of biomembranes

Divalent cations play an important role in the functions of biomembranes. This review deals with three topics: (1) Mg²⁺-mediated change in physical state of phospholipid induces conformation and activity change of reconstituted mitochondrial H⁺-ATPase, (2) a proper transmembrane Ca²⁺ gradient is essential for the higher enzymatic activity of adenylate cyclase, and (3) role of transmembrane Ca²⁺ gradient in the modulation of reconstituted sarcoplasmic reticulm Ca²⁺-ATPase activity.     

Trace elements in hair of blackfoot disease

Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Though extensive epidemiological study has implicated that high arsenic content in artesian well water of the endemic area, bears some important connection with the disease, the etiology of the disease is still unknown. In this study, attention is paid to multielement determination in order to find out whether the trace elements in hair of Blackfoot disease patients are different from those of the controls. Experimental results indicate that the concentrations of As and Se in hair of patients are significantly higher than those of the controls, but Ca and Zn are significantly lower than those of the controls. The possible connection of these elements with the etiology of the disease is discussed.     

Autophosphorylation-dependent protein kinase predominantly phosphorylates Ser115, thein vivo site in brain myelin basic protein

In a previous report [Yanget al., (1987a),J. Biol Chem. 262, 7034–7040], a cyclic-AMP- and calcium-independent brain kinase which requires autophosphorylation for activity was identified as a very potent myelin basic protein (MBP) kinase. In this report, the phosphorylation sites of MBP by this autophosphorylation-dependent protein kinase (autokinase) are further determined by two-dimensional electrophoresis/thin-layer chromatography, phosphoamino acid analysis, high-performance liquid chromatography, tryptic peptide mapping, sequential manual Edman degradation, and direct peptide sequencing. Autokinase phosphorylates MBP on both threonine and serine residues. Three major tryptic phosphopeptide peaks were resolved by C₁₈-reversed phase highper-formance liquid chromatography. Sequential manual Edman degradation together with direct sequence analysis revealed that FS(p)WGAEGQKPGFGYGGR is the phosphorylation site sequence (molar ratio ～1.0) for the first major phosphopeptide peak. When mapping with bovine brain MBP sequence, we finally demonstrate Ser¹¹⁵, one of thein vivo phosphorylation sites in MBP, as the major site phosphorylated by autokinase, implicating a physiologically relevant role of autokinase in the regulation of brain myelin function. By using the same approach, we also identified HRDT(p)GILDSLGR (molar ratio ～0.9) and TT(p)HYGSLPQK (molar ratio ～0.8) as the major phosphorylation site sequences in³²P-MBP phosphorylated by autokinase, further indicating that -Arg-XSer/Thr-(neutral amino acid)₃-(amino acid-containing hydroxyl group such as Ser/Glu/Asp)-(neutral amino acid)₂-may represent a unique consensus sequence motif specifically recognized by this autophosphorylation-dependent multisubstrate/ multifunctional protein kinase in the brain.