棉花耐盐变异体的筛选与再生（简报）

在１０ｇ／Ｌ ＮａＣｌ培养基上筛选出的愈伤组织能分化出体细胞胚和再生植株,并获得了耐２０ｇ／Ｌ ＮａＣｌ的体细胞胚。     

苜蓿抗甲硫氨酸变异体的筛选

紫花苜蓿(Medicago sativa L.)下胚轴愈伤组织用NaN_3溶液诱变处理后,在含有全致死浓度甲硫氨酸的MS培养基上进行了6个月的连续筛选培养,获得了能抗100mmol/L甲硫氨酸的变异细胞系,并分化成再生植株。所获变异细胞系在脱离选择压力6个月后,对甲硫氨酸的抗性仍比对照高7.2倍,并表现出对乙硫氨酸的交叉抗性(为对照抗性的3.3倍)。抗性细胞系及其再生植株的甲硫氨酸、赖氨酸、苏氨酸和异亮氨酸含量均比对照有大幅度增加。抗性系的SDS-PAGE电泳图谱及过氧化物酶同工酶谱带均与对照有显著不同,并出现了新带,表明变异系已经产生变化了的基因产物。     

运用α-吡啶羧酸筛选水稻抗稻瘟病细胞变异体的研究

利用α-吡啶羧酸为胁迫因子,研究了花药培养筛选水稻(Oryza sativa L.)抗稻瘟病(Pyricularia oryzae Cav.)细胞变异体的效果。α-吡啶羧酸可抑制水稻花药(粉)愈伤组织的形成与生长,用40mg-L α-吡啶羧酸进行诱导、继代和分化筛选,可获得抗性愈伤组织并再生绿苗,但仅有一半绿苗自然加倍结实,并具备对稻瘟病孢子悬浮液的抗性。经两代选择与鉴定,获得了抗稻瘟病 ZA_1和 ZB_(11)小种、但感 ZG_1小种的变异体2-07和4-091。     

水稻抗氨基酸类似物突变体的筛选——Ⅰ.抗S-(2-氨乙基)L-半胱氨酸(AEC)突变体的筛选

以赖氨酸类似物S-(2-氨乙基)L-半胱氨酸(AEC)为选择剂,从水稻花药培养中筛选出一个抗性突变体(R_(AEC))。突变体愈伤组织经过6个月继代培养后仍保持抗性稳定。R_(AEC)再生植株根尖诱导的愈伤组织经过3个月继代培养也保持稳定的抗性。R_(AEC)细胞内赖氨酸含量提高了近2倍,苏氨酸提高5倍多。其他氨基酸,如蛋氨酸、酪氨酸、丝氨酸等都有较大量的提高。 R_(AEC)愈伤组织对赖氨酸加苏氨酸混合物也具有抗性。突变体植株较原始类型稍矮小,巳正常结实。     

红豆草抗甲硫氨酸变异体的筛选

用ＮａＮ３ 诱变过的红豆草（Ｏｎｏｂｒｙｃｈｉｓｖｉｃｉａｅｆｏｌｉａ Ｓｃｏｐ．）愈伤组织筛选得到了能抗８０ ｍ ｍ ｏｌ／Ｌ甲硫氨酸的变异细胞系——ＯＮｍ ｅｔｒ,并得到了再生植株。ＯＮｍ ｅｔｒ 脱离选择压力６ 个月后,其抗性仍比野生型的高５．６ 倍。同时还表现出对乙硫氨酸的交叉抗性,其抗性是野生型的６．５ 倍, 表明该抗性系抗性表达稳定。ＯＮｍ ｅｔｒ 愈伤组织中甲硫氨酸、赖氨酸、苏氨酸含量分别是野生型的４．００、１．０９、１．５０ 倍。ＯＮｍ ｅｔｒ再生植株中甲硫氨酸、赖氨酸、苏氨酸、异亮氨酸含量分别为野生型的２．０、３．５、３．５、２．５ 倍。在ＯＮｍ ｅｔｒ 愈伤组织可溶性蛋白ＳＤＳ－ＰＡＧＥ图谱中,出现了两条新多肽（３０ ｋＤ、２６ ｋＤ）。ＯＮｍ ｅｔｒ 细胞系过氧化物酶同工酶谱中亦出现了两条新酶带。这些变化表明该变异系已经产生变化了的基因产物     

Isolation of a recessive barley mutant resistant to S-(2-aminoethyl)L-cysteine

Summary S-(2-aminoethyl)L-cysteine (AEC) inhibits the growth of mature barley (Hordeum vulgare L vars. Bomi and Maris Mink) embryos grown on sterile medium. This inhibition is relieved by lysine and, to a lesser extent, arginine and ornithine. In order to try and select plants which accumulate lysine, 8200 M2 embryos of sodium azide mutagenised barley were screened for growth in the presence of 0.25 mM AEC. One line, R906 was selected for further characterisation. Progeny of the originally selected plant after selfing were all resistant to AEC. In a reciprocal cross with a sensitive barley the resistant trait was inherited as a single recessive nuclear gene which we designate aec-1.Abbreviation AEC S-(2-aminoethyl)L-cysteine     

Selection and Characterization of Asparagus Mutants Resistant to Inhibition by Lysine Plus Threonine

Asparagus officinalis calli were induced from shoot of seedlings. After mutagenization, two lysine plus threonine resistant mutant lines (LTR2, LTR3) were obtained by selectionnonselection-reselection procedures with 2 mmol/1 lysine plus threonine. LTR2 and LTR3 caIli remained resistance to lysine plus threonine after being subcultured for 1 year, and both of them showed cross resistance to 1 mmol/l aminoethylcysteine. In resistant calli, the free lysine, methionine and an unknown amino acid were l-l0 times more than those in controls.     

Selection and Characterization of Maize Variants Resistant to S-(2-Aminoethyl)-L-Cysteine and 5-Methyltryptophan

Using tissue culture selection techniques, variants resistant to S-(2-aminoethyl)-L-cysteine (AEC) and 5-methyltryptophan(5MT) were, respectively, isolated from Opaque-2 maize inbred line “Zhongxi 037/02” and “Zhongxi 091/02”. After growing 5 months on AEC free medium, the AEC-resistant cell line (Raec) still showed high level AEC resistance which was 4 times. higher than that of its wild type, “Zhongxi 037/02”. The resistance was expressed at the plant level. New cultures initiated from shoot tissue of plants regenerated from Raec was also resistant to AEC inhibition. The free pool of lysine, threonine, isoleucine, methionine and arginine increased 0.5–3.4 fold in Raec culture. The aspartokinase from both AEC-resistant and -sen- sitive lines exhibited similar sensitivity to lysine and AEC inhibition. But the aspartokinase activity in the resistant line was 2.3 times of that in sensitive line. Seed were obtained from the plants resistant to AEC when crossed with pollen of sensitive plants. The resistance of 5MT-resistant cell line, tested after growth for 11 months on nonselection medium, was 3.5 times higher than that of its wild type, “Zhongxi 091/02”. The 5MT-resistance was possibly due to the accumulation of free tryptophan (from 0 to 61.6 nmol/g fr. wt) in the resistant cells. There was also an increase in free phenylalanine (14.5 fold) and tyrosine (28.8 fold).     

耐冬山茶子叶再生体系的研究

青岛市市花——耐冬山茶为北方珍贵的冬季观赏物种,目前其栽培数量不能满足园林应用,亟需通过组培扩繁。以耐冬山茶的子叶为外植体,探讨不同因素对子叶愈伤组织诱导及植株再生的影响。结果表明,使用2%的NaClo对耐冬山茶果实灭菌的较佳时间是8 min,子叶愈伤组织的诱导率为100%。耐冬山茶子叶愈伤组织增殖的较优激素配比为0.5 mg·L^-1NAA+1.5 mg·L^-16-BA,其最大增殖量为4.06。将经过2次转接继代培养后的愈伤组织转入不定芽分化培养基MS+1.0mg/LNAA+10.0 mg·L^-16-BA进行不定芽的分化诱导,不定芽的分化率为10.7%。将耐冬山茶的不定芽芽条基部浸没在500 mg·L^-1的IBA溶液中70 min,再转接到1/2MS固体培养基,生根率达40%,成功建立了耐冬山茶子叶的植株再生体系。     

Preparation of 2S-(—)-4-Amino-2-Hydroxybutanoic Acid via Yeast-Catalyzed Stereoselective Reduction

The unusual amino acid S2-(—)-4-amino-2-hydroxybutanoic acid (S-AHBA) (1), a structural component of the antibiotic Amikacin, has been prepared via yeast-catalyzed stereoselective reduction of methyl-4-benzyloxycarbonyloxyamino-2-oxobutanoate (5). The most suitable yeast was found to be Saccharomyces carlsbergensis ATCC2345 and Saccharomyces sp. Edme, which gave 40% and 54% yield, respectively, of (S)-(+)-6 (88% ee).     

中间偃麦草(Thinopyrum intermedium)18S-5.8S-26S rDNA位点在染色体上的分布及对其核ITS序列异质性的分析

中间偃麦草(Thinopyrum intermedium(Host)Barkworth et Dewey)是禾本科小麦族植物中的一个异源六倍体物种,是重要的牧草植物,在小麦的抗病育种中发挥了重要作用.利用荧光原位杂交(FISH)技术,在体细胞中期染色体上,对18S-5.8S-26S rDNA位点进行了物理定位,发现该物种有3～4对染色体携带18S-5.8S-26S rDNA主位点.结合基因组原位杂交(GISH)分析,证明中间偃麦草的St基因组中有一对同源染色体短臂末端携带一个主位点,其余2～3对主位点位于E基因组染色体上.对不同来源的材料研究表明:18S-5.8S-26S rDNA位点的数目(包括主位点和小位点)、位置、拷贝数在不同收集材料之间的差异较大,甚至在同一个体的不同细胞中也存在差异.讨论了rDNA物理作图数据在分析系统发育问题中的局限性.结合中间偃麦草的三个可能的二倍体基因组供体(Th.bessarabicum、Th.elongatum和Pseudoroegneria stipifolia)rDNA位点分析的结果,对中间偃麦草进化过程中rDNA位点的变化进行了分析,同时,对其中一份材料的核ITS序列进行了克隆、测序和系统发育分析,发现在中间偃麦草中,ITS序列具有很高的异质性.     

天门冬属九种药用植物的氨基酸和微量元素分析

百合科(Liliaceae)天门冬属(Asparagus (Tourn.)L.)植物具有悠久的药用历史,如天门冬(A.cochinchinesis (Lour) Merr.)早在汉代《神农本草经》中就被列为上品,具有滋阴、润燥、降火、止咳等功效。现代药理研究及临     

Reaction of S-(2-amino-2-carboxyethylsulfonyl)-L-cysteine with thiosulfate: synthesis of L-alanine sulfodisulfane and application to the determination of thiosulfate

A new reaction of S-(2-amino-2-carboxyethylsulfonyl)-L-cysteine (ACESC) with thiosulfate is described. The reaction proceeded quantitatively in formic or acetic acid solutions, yielding equimolar amounts of L-alanine sulfodisulfane (2-amino-2-carboxyethyl sulfodisulfane) and L-alanine 3-sulfinic acid. L-Alanine sulfodisulfane was obtained as pure monosodium salt; the yield was 92% of the theoretical. A new method is described for the determination of thiosulfate. The method is based on the quantitative reaction between ACESC and thiosulfate, and L-alanine sulfodisulfane, one of the reaction products, was determined using acid ninhydrin reagent 2 of M. K. Gaitonde (1967, Biochem. J. 104, 627-633). The recovery was over 95%. When samples contained sulfite in addition to thiosulfate, S-sulfo-L-cysteine (T. Ubuka et al., 1982, Anal. Biochem. 126, 273-277) was produced in addition to L-alanine sulfodisulfane by the treatment with ACESC. Both products were separated by a small Dowex 1 column and determined with the acid ninhydrin reagent 2. The recoveries were over 95%. The new method was applied to the thiosulfate sulfurtransferase reaction, in which thiosulfate, a substrate, and sulfite, a product, were determined separately.