植物表达载体pGMAR-BADH的构建

将甜菜碱醛脱氢酶基因BADH和植物表达载体pGMAR通过内切酶BamHI和KpnI双酶切,T4连接酶进行连接反应。重组质粒在大肠杆菌菌株DH5α内扩增,提取并纯化质粒。经鉴定,基因BADH已被完整、正确的插入到pGMAR载体中,并成功将BADH插入到载体pGMAR的两个MAR序列之间。     

干旱胁迫对枣树叶片生理的影响

以盆栽2年生蒙山脆枣和沾化冬枣为试材,研究了不同干旱胁迫程度对叶片水分饱和亏、叶片保水力、游离脯氨酸含量、SOD活性、POD活性、甜菜碱含量等生理指标的影响。结果表明:尽管品种间的变化存在差异,但随着干旱胁迫程度的加重,两品种的叶片保水力呈下降趋势,水分饱和亏、Pro含量、甜菜碱含量呈增加趋势,SOD、POD活性呈先升高后下降趋势;高含量的甜菜碱有利于枣叶片保持较高的水分含量,甜菜碱、Pro含量与枣品种的抗旱性存在一定的正相关关系,可以作为枣品种抗旱性鉴定的指标。     

硫辛酸和甜菜碱在小麦组织培养中的作用

为了研究不同浓度的硫辛酸和甜菜碱对农杆菌侵染后小麦愈伤组织的影响,选取小偃22、Z50和郑麦366的幼胚为外植体,进行农杆菌介导的遗传转化。在抑菌培养基中分别添加2、4和8 mmol·L~(-1)的硫辛酸和10 mmol·L~(-1)的甜菜碱,于5、10和15 d分别观察统计小麦愈伤组织的褐化和水渍化程度。结果表明,添加硫辛酸可有效降低愈伤组织的褐化程度,Z50中添加4 mmol·L~(-1)硫辛酸可使褐化程度较CK降低89.50%,但会提高愈伤组织的水渍化程度;添加10 mmol·L~(-1)甜菜碱对愈伤组织的褐化程度和水渍化程度均无明显影响。     

超高效液相色谱-串联质谱法同时测定海藻肥中的甘露醇和甜菜碱

建立了超高效液相色谱-串联质谱法同时检测海藻肥中甘露醇和甜菜碱的新方法。使用Waters BEH C18色谱柱,流动相为乙腈和5 mM乙酸铵溶液,流速为0.3 mL/min,柱温为35 ℃。采用正负离子同时扫描的方式测定,甘露醇和甜菜碱m/z为89和59.2;母离子的m/z分别为181和118,结果以外标法进行计算。结果表明,甘露醇和甜菜碱在本方法中的线性范围分别为5-50 和0.05-0.5 mg/L,当S/N为3时检出限分别为0.18和0.083 mg/L。两种物质分别在3个水平进行加标回收实验,甜菜碱的平均加标回收率在80.3-109.44%之间;甘露醇的平均加标回收率在85.52-106.55%之间,满足实际应用需求。     

外源甜菜碱对盐胁迫下大麦幼苗体内多胺和离子含量的影响

外源甜菜碱对200 mmol/L NaCl胁迫下大麦幼苗的伤害有显著的缓解效应,0.5～10.0 mmol/L的甜菜碱均可以有效抑制盐胁迫导致的叶片中MDA含量的上升,增加根系含水量与幼苗鲜重,降低植株体内Na+/K+比,尤以1 mmol/L甜菜碱的效应最明显。甜菜碱可以显著地提高盐胁迫下大麦幼苗根系多胺含量,促进叶片内腐胺与亚精胺向精胺的转化     

甜菜碱促进肉鸭生长的作用机理研究试验研究

选用1日龄樱桃谷肉用仔母鸭864羽,随机分成6组(每组设6个重复),各组按2种剂量水平(0和0.05%)的甜菜碱和3种剂量水平(0、0.06%和0.12%)的蛋氨酸分别组合添加进行2×3析因法设计.结果表明,在蛋氨酸相对缺乏的饲料中甜菜碱能高效替代蛋氨酸,甜菜碱对改善肉鸭屠体品质比蛋氨酸更为有效;甜菜碱和蛋氨酸在增重、料重比、胸肌率、腹脂率、肝脏中的甜菜碱一高半胱氨酸S-甲基转移酶(BHMT)的活性和胸肌中肉碱含量则无明显互作效应.     

Changes in hormones, growth factor and lipid metabolism in finishing pigs fed betaine

An experiment was conducted to investigate the effect of dietary betaine supplementation on carcass characteristics, hormones, growth factor and lipid metabolism in finishing pigs. Forty-eight crossbred barrows and gilts (Seghers × Seghers × Duroc) weighing about 55 kg were divided into two groups, each with three replicates of eight pigs (four barrows and four gilts) per replicate, and fed corn–soybean meal basal diets supplemented with 0 and 0.125% betaine for 42 days. At trial termination, two pigs (one barrow and one gilt) weighing about 90 kg were selected from each replicate and slaughtered for analyses. The results showed that betaine increased carcass lean percentage and longissimus muscle area by 5.19% (P < 0.01) and 17.85% (P < 0.01), respectively, and decreased carcass fat percentage and average backfat thickness by 13.07% (P < 0.01) and 10.30% (P < 0.05), respectively. Serum growth hormone, insulin-like growth factor I, free triiodothyronine, free thyroxine and insulin levels in pigs fed betaine were elevated by 45.61% (P < 0.01), 55.50% (P < 0.01), 57.95% (P < 0.01), 51.80% (P < 0.01) and 42.34% (P < 0.05), respectively. Fatty acid synthase activity in the 10th rib subcutaneous adipose tissue was decreased by 24.35% (P < 0.05) with betaine supplementation, whereas hormone-sensitive lipase activity was significantly increased (P < 0.05). Meanwhile, serum free fatty acids concentration in betaine-fed pigs was 25.75% higher compared to controls (P < 0.01). The study suggested that betaine could induce changes in hormones and growth factor in finishing pigs, and therefore could inhibit fat synthesis through reducing lipogenic enzymes activities and promote fat degradation by increasing hormone-sensitive lipase activity, with a resultant decrease in adipose tissue mass and improvement in carcass characteristics.     

转甜菜碱醛脱氢酶基因马铃薯的抗旱耐盐性

通过根癌农杆菌介导法将甜菜碱醛脱氢酶(BADH)基因导入马铃薯栽培品种甘农薯2号, 经PCR、Southern杂交和Northern杂交证明BADH基因已整合到马铃薯基因组中并在转基因植株中转录和表达。测定表明对照植株没有BADH酶活性, 各转化株系在胁迫前后BADH酶活性近似, 在2~11 U之间。BADH酶活性与叶片的相对电导率呈一定的负相关(y= –3.7738x+57.083, r=0.989^**)。在NaCl和PEG胁迫下, 转基因植株生长正常, 株高比对照提高0.41~1.00 cm, 单株重量比对照增加10%~35%, 说明外源BADH基因的导入提高了马铃薯植株对干旱和盐碱的抗性。     

水分胁迫对桃、草莓、板栗和平邑甜茶叶片、茎及根中甜菜碱含量的影响

以桃、草莓、板栗和平邑甜茶4个树种为试材,对水分胁迫下其叶片、茎以及根中甜菜碱含量的变化进行了初步探讨,结果表明:在正常供水条件下,各树种的叶片、茎和根中都有一定量的甜菜碱,不同树种、同一树种的不同器官甜菜碱的含量均不同;板栗的甜菜碱含量最高,平邑甜茶的含量最低;叶片的甜菜碱含量最高,根部的含量最低。水分胁迫下,各树种的甜菜碱含量都显著增加,不同树种变化幅度不一。胁迫程度不同,甜菜碱含量的变化趋势也不同。轻度水分胁迫下,平邑甜茶增幅最大,其次是桃和草莓,板栗增幅最小;中度水分胁迫下,平邑甜茶的增幅最大,其次是板栗、桃、草莓。     

Effect of N-methyl-aspartate and Betaine on Growth Performance and Correlation Between Growth Hormone, Growth Performance and Carcass Composition in Finishing Pigs

［1］Etherton T D. Anabolic effects of porcine somatotropin on pig growth in: Designing foods: Animal product options in the marketplace. National Academy Press, Washington, DC. 1988:194 - 202. ［2］XU Z R, et al. Effect of betaine on carcass characteristics and approach to mechanism of the effect in finishing swine. Acta Veterinaria et Zootechnica Sinica, 1998, 29(5) :397 - 405. (in Chinese) ［3］Knight C D, et al. The performance and carcass composition responses of finishing swine to a range of porcine somatotropin doses in a l-week delivery system. J. Anim. Sci. 1991, 69:4678 - 4689. ［4］Zhou S W, et al. Effect of the recombinant porcine somatotropin on weight gain and carcass composition in swine. Journal of Beijing Agricultural University, 1993, 19: 93 97. (in Chinese) ［5］Danghaday W H. Double effect of growth hormone. Nature,1972..235 - 237. ［6］Estienne M J, et al. N-methyl-D, L-aspartate induced growth bermine secretion in barrows: possible mechanisms of action. J.Anim. Sci. 1996, 74:597- 602. ［7］Barb C R, et al. Aspartate and glutamate modulation of growth bormone secretion in the pig: Possible site of action. Domest.Anim. Endocrinols. 1996, 13:81 - 90. ［8］Lindstrom P, et al. Effect of N-methyl-D, L-aspartate on isotated rat somatotrophs. Endocrinology, 1992, 131: 1903 -1907.