海岛棉转录因子基因GbMYB60的克隆、表达及其抗逆性分析

MYB转录因子是在真核生物细胞内广泛存在的一类转录因子蛋白,在植物的生长发育、代谢调节、抗病抗逆、以及激素介导的信号路径等方面都发挥着重要的作用。本研究从海岛棉品种海7124中克隆得到一个MYB转录因子基因,根据序列同源性和进化分析,将其命名为GbMYB60。该基因序列长990 bp,编码一个36.9 kD的R2R3类MYB转录因子蛋白。GbMYB60蛋白被特异地定位于植物细胞核。GbMYB60基因的表达水平较低,在真叶中优势表达,根系中表达量最低。该基因受甘露醇、NaCl、低温、高温等非生物逆境,以及脱落酸、乙烯利、茉莉酸甲酯和水杨酸等植物激素的诱导上调表达。利用病毒诱导的基因沉默技术在海岛棉中干涉GbMYB60发现,降低GbMYB60基因的表达水平,使棉花幼苗对高盐胁迫的耐受性降低;但GbMYB60干涉的植株在甘露醇溶液的处理下与对照植株并无显著的抗性差异。     

比色法测定蒙山九州虫草中甘露醇的含量

利用比色法测定蒙山九州虫草菌丝体和子座中甘露醇含量。结果表明,甘露醇在412 nm处,质量浓度在10~100μg/ml范围内呈现良好线性关系,其回归方程Y=-0.00685+0.01066X,r=0.99947(P<0.0001);平均回收率为97.3%,RSD为2.1%(n=5)。用此法测得蒙山九州虫草菌丝体和子座中甘露醇含量分别为10.84%和7.78%。     

香棒虫草和冬虫夏草中甘露醇和麦角甾醇的测定分析

本文采用药典法和薄层层析法对香棒虫草和冬虫夏草中甘露醇和麦角甾醇进行了测定 ,对它们的药用价值作了比较分析     

高温胁迫下甘露醇对离体小麦叶片生理特性的影响

在４０℃高温胁迫下，用甘露醇（５０μｍｏｌＬ＾－１）和蒸馏水（ＣＫ）处理后小麦旗叶离体叶片结果显示，甘露醇能降低叶片脯氨酸含量，在实验后０～２ｈ延缓蛋白质降解，增加过氧化物酶活性，在实验后０～４ｈ能有效减少叶绿素破坏，说明低浓度甘露醇对高温胁迫下的离体小麦叶片具有一定保护作用。     

电晕处理对肉苁蓉表面性能及甘露醇溶出量的影响

为提高肉苁蓉的利用率,对肉苁蓉粉体表面进行电晕等离子体改性处理,并对粉体中甘露醇在水中溶出量进行测定。采用扫描电子显微镜、激光粒度分析、红外光谱分析等多种测试方法分析电晕改性处理前后粉体样品的表观形貌和表面性能的变化规律,对比改性机理进行讨论。结果表明,电晕处理后,粉体表面粗糙,亲水基团含量增加,材料表面润湿性能得到明显改善,甘露醇在水中溶出量也明显增加。其中,最佳的电晕工艺是为0.5kW电晕功率处理2min,此时改性效果最好,甘露醇在水中浸泡20min的溶出率达到63.9%,较未处理的原始样品提高45.8%。通过对肉苁蓉粉末表面进行电晕改性处理,能够有效改善粉体的表面性能,使材料中有效药物成分最大限度地溶出,从而提高中国宝贵中药资源的利用率。     

Effect of carbohydrates on in vitro low-temperature storage of shoot cultures of apricot

Procedures for cold storage of in vitro cultures can delay subculturing, reducing production costs and risks of contamination and somaclonal variation. The present work investigates the effects of media with sorbitol (116.8 mM, medium SO) or sucrose (58.4 mM) alone (medium SU), or the latter in combination with mannitol (58.4 mM, medium M) on 7-month storage at 5 °C of apricot shoots, cv San Castrese and Boreale. Shoots in SO survived in lower percentages and grew less than in the other treatments during storage, and died in large numbers after transfer to standard culture conditions. In comparison to other treatments, survival was 100% in the presence of M and both shoot weight and number of surviving proliferated axillary shoots was increased. Moreover, M improved regrowth compared to SU under standard culture conditions. The SOD and CAT activity confirmed the higher stress of shoots stored in SO than controls, and in contrast, the low stress of shoots in M.     

以菊芋为原料发酵生产甘露醇的研究

研究7株乳酸菌发酵菊芋生产甘露醇的能力.其中,有5株乳酸菌无须添加氮源和无机盐,能够有效转化40 g/L糖化菊芋汁中的果糖合成甘露醇.进一步发酵还原糖浓度为169 g/L的浓缩汁时,通过比较甘露醇产量和还原糖利用率,选择了一株能有效转化糖化菊芋汁中果糖合成甘露醇的菌株M-1,可产出80 g/L甘露醇.分析碳源比例对M-1发酵的影响,培养基中果糖和葡萄糖的浓度比为4∶1时,M-1产出甘露醇73.8 g/L,还原糖转化率达74.10 %.进一步证明糖化菊芋汁的糖成分满足需要,可作为甘露醇生产的合适发酵原料.     

蛹虫草活性成分的测定

分别用薄层层析法和高碘酸氧化法测定了蛹虫草(Cordyceps militaris)、冬虫夏草(C.Sinensis)及其发酵菌丝中腺苷和甘露醇的含量。结果证明,蛹虫草Y3菌株发酵菌丝的甘露醇含量达16.04％,明显高于天然蛹虫草。不同来源的蛹虫草的腺苷含量相近,为1.4％左右。刚联苯三酚自氧化法测定了蛹虫草的SOD)活性,人工栽培的蛹虫草SOD)活性最高,为1882U/mgPr。上述结果表明,蛹虫草具有和冬虫夏草相似的药效成分,有重要的开发应用价值。     

Effect of different irrigation regimes on carbohydrate partitioning in leaves and wood of two table olive cultivars (Olea europaea L. cv. Meski and Picholine)

In this study, changes in carbohydrate composition were investigated at the end of the biological cycle of two important table olive cultivars ‘Meski’ and ‘Picholine’ grown in Tunisia under different irrigation regimes. A control treatment [100% crop evapotranspiration (ETc)] and a stress treatment (50% ETc) were considered. At the end of August, leaf water potential was measured and sugar compounds were determined in mature leaves and in the wood of fruit-bearing branches by gas chromatography. The leaf water potential increased with the stress treatment in both cultivars, but the increase was more pronounced with ‘Picholine’ than with ‘Meski’. Glucose, fructose, mannitol, sucrose, galactose and inositol were the main sugars found in the leaves and wood of olive trees. Glucose, fructose and mannitol accounted for 90% of the total soluble carbohydrate fraction. The fraction and amount of these sugars changed between cultivars and with irrigation treatment. In the control treatment, the leaves of Meski showed a high level of glucose (48%), fructose (19%) and mannitol (25%), while the leaves of Picholine showed amounts of 57, 15 and 17%, respectively. The restriction of irrigation water (50% ETc) induces an accumulation of glucose in the leaves and wood of ‘Meski’ and an accumulation of mannitol and glucose in the wood of ‘Picholine’, while the leaves showed only an increase in mannitol.     

甘露醇-1-P脱氢酶转基因表达对转基因水稻幼苗抗盐性的影响

现已证实,在转基因烟草中超量合成并积累低分子量化合物,可以增强植物对包括盐渍在内的非生物逆境的抗性。这些低分子量化合物包括甘露醇、脯氨酸、果聚糖、甜菜碱、海藻糖和芒柄醇等。在大肠杆菌中甘露醇－１－Ｐ脱氢酶（ＥＣ１．１．１．１７）,由ｍｔｌＤ基因编码并催化Ｄ－甘露醇的运输和利用〔２〕。然而,在转基因烟草（ＮｉｃｏｔｉａｎａｔａｂａｃｕｍＬ．）〔５〕和拟南芥（ＡｒａｂｉｄｏｐｓｉｓｔｈａｌｉａｎａＬ．）〔６〕中,ｍｔｌＤ转基因表达却导致甘露醇的合成和积累并对ＮａＣｌ处理产生很强的抗性。本研究用ｍｔｌ…