1株粗糙型布鲁氏菌诱导株RB71的生物学特性研究

目的通过研究1株粗糙型布鲁氏菌诱导株RB71的毒力及免疫效果,进一步验证其生物学特性,探讨其作为疫苗株的潜力。方法通过药敏片扩散法检测诱导株RB71对β-内酰胺类及非β-内酰胺类抗生素的耐受程度;通过对小鼠脾脏载菌量测定,评价诱导株RB71对感染小鼠的免疫保护率并确定其最小免疫剂量;利用小鼠感染模型进行毒力试验,比较诱导株RB71与亲本株的毒力差异。结果诱导后的布鲁氏菌RB71株与亲本株相比,对β-内酰胺类抗生素和非β-内酰胺类抗生素的敏感性未发生改变;诱导株RB71对感染小鼠具有一定的保护效果,最小免疫剂量为10^(9)CFU/只;诱导株RB71与亲本株相比毒力更小,安全性更高。结论本研究验证了布鲁氏菌诱导株RB71对抗生素的敏感性,其具有良好的免疫原性且具有较低的毒力,具备成为疫苗株的潜力。

非洲菊叶片离体诱导成株的激素调控

以Sangria品种为试验材料 ,叶片为外植体 ,进行离体快繁激素调控技术的研究 ,结果表明 :35个激素组合配比中 ,都能形成愈伤组织 ,愈伤组织的诱导率为 10 0 % ;不定芽诱导的最佳培养基为MS +4.0mg/L(毫克 /升 )BA +0 .2mg/L(毫克 /升 )IAA ,不定芽的诱导率可达 10 0 % ;从增殖系数、试管苗的质量综合评判得出的最佳增殖培养基也为MS +4.0mg/L(毫克 /升 )BA +0 .2mg/L(毫克 /升 )IAA ,繁殖系数可达 14 ;MS附加IAA0 .2mg/L(毫克 /升 )～ 0 .5mg/L(毫克 /升 )的培养基的生根率可达 80 %以上 ,且随着培养时间延长 ,生根率会不断提高。培养 30d(天 )时 ,生根率可达 90

盾叶薯蓣试管株芽的诱导

以盾叶薯蓣(Dioscoreazingiberensis)试管植株为材料,选取带芽茎段为外植体,转接到株芽诱导培养基上15d后,原茎段基部开始产生株芽突起,30d后每一茎段可产生3-5个已生根的株芽,株芽诱导率为100%,株芽诱导数为180个/40株,其移栽成活率可达90%以上。株芽形成的适宜培养条件:温度为26±2℃,光照时间14hd-1,光照强度为1500-2000lx;适宜培养基组成为:MS+6-BA4.0mgL-1+IBA1.0mgL-1+蔗糖6%-9%+活性炭0.5%+琼脂7%。离体诱导的盾叶薯蓣试管株芽能直接发育为新植株,为盾叶薯蓣的快繁提供了一种新的方法。

外源茉莉酸诱导方式对长白落叶松针叶内防御蛋白活力的影响

为明确用茉莉酸不同处理方式对林木诱导抗虫性的影响,以长白落叶松（Larix olgensis）幼苗为试验材料,分别用浓度为1.00、0.10、0.01 mmol·L-1的茉莉酸进行全株或局部喷施诱导,分析不同处理对其针叶内SOD、PPO、PAL、CI、TI 5种防御蛋白活力的影响。结果表明：用外源茉莉酸局部喷施长白落叶松,可以系统诱导增强其防御蛋白的活性,且诱导效果与全株喷施处理的诱导效果相近。0.10、1.00 mmol·L-1的茉莉酸在1~10 d内即可诱导产生较强的诱导抗性,而在15~25 d时其诱导的抗性强度显著低于0.01 mmol·L-1浓度的诱导效果。说明高浓度茉莉酸能快速诱导长白落叶松产生较强的化学防御能力,低浓度茉莉酸诱导长白落叶松化学防御的速度相对迟缓,但其持效时间长于高浓度茉莉酸诱导效果。在害虫控制实践中,可根据害虫的生物特性,选择合适浓度的茉莉酸,采用局部喷施方式施用,将更为经济和便于操作。

3种抗菌药物诱导改变marA、soxS和robA基因mRNA表达水平

本研究旨在探讨不同类抗菌药物诱导引起大肠肝菌主动外排系统调控基因marA、soxS、robA表达水平的变化特点。挑选大肠杆菌标准菌株O78经阿米卡星(AMK),环丙沙星(CIP),头孢曲松钠(CRO)逐代诱导的10、20、30代菌株作为试验菌株,提取其总RNA并反转录,采用荧光定量RT-PCR的方法测定其主动外排调控基因marA、soxS、robA的mRNA表达水平。结果表明:marA基因在CIP20中mRNA的表达水平最高,是母体菌株O78的2.30倍,且其在CIP10、CRO30、CIP30、AMK20的表达量分别为母体菌株O78表达量的2.11、1.71、1.15、1.44倍;soxS基因在AMK20中的表达量最高,是母体菌株的5.98倍,其它高于O78的菌株表达量的菌株为CRO30、CRO20、CIP20、CIP30;robA基因mRNA表达量除了在CIP10的表达量高于O78外,其余均低于母体菌株的表达。结果提示头孢曲松、环丙沙星、阿米卡星能诱导菌株的主动外排调控基因marA、soxSmRNA表达增加,robA基因mRNA表达减少。

茉莉酸甲酯局部诱导长白落叶松对舞毒蛾生长发育的影响

为了解茉莉酸甲酯局部处理对林木诱导抗虫性的影响,本研究以长白落叶松幼苗为试验材料,分别用浓度为0.01、0.10和1.00 mmo L/L的茉莉酸甲酯全株或局部喷施处理,分析不同处理苗木对舞毒蛾生长和繁殖的影响。结果表明,取食3个浓度茉莉酸甲酯局部或全株处理过的长白落叶松后,舞毒蛾的3-6龄幼虫平均质量、蛹质量以及成虫产卵量与对照组相比均显著下降（P〈0.05）,幼虫存活率、化蛹率、羽化率也都低于对照组,且相同浓度的局部处理与全株处理间结果相近,无显著差异（P〉0.05）,其中0.10 mmo L/L茉莉酸甲酯局部处理诱导效果最好。本研究结果说明3个浓度茉莉酸甲酯局部和全株处理后均能不同程度诱导长白落叶松增强其对舞毒蛾生长发育的抑制能力,并且茉莉酸甲酯局部喷施长白落叶松可以达到全株喷施的诱导效果,以0.10 mmo L/L浓度的诱导效果最好。

Avermectin产生菌异亮氨酸诱导变种的选育

用紫外线处理ａｖｅｒｍｅｃｔｉｎ（ＡＶＭ）产生菌ＳｔｒｅｐｔｏｍｙｃｅｓａｖｅｒｍｉｔｉｌｉｓＸＣ１－２５，并在含有Ｌ－异亮氨酸（Ｌ－Ｉｌｅ）的平板培养基上筛选Ｌ－Ｉｌｅ诱导变种。结果表明：Ｉｌｅｉ变株发酵产生的ＡＶＭＢ１ａ效价高于自然分离株与紫外线诱变株，其中Ｉｌｅｉ变株ＸＣ２－２６的ＡＶＭＢ１ａ效价较亲株提高２２％。该变株经自然分离获得菌株ＸＣ３－８，其ＡＶＭＢ１ａ效价比出发菌株提高５０％以上，传代试验表明菌株ＸＣ３－８的形态和高产性能稳定，它在７ｍ３发酵罐生产试验，产生ＡＶＭＢ１ａ效价与发酵指数均比出发菌株提高５６％。

Characterization and synthetic biology elements of nonmodel bacteria,Acetobacteraceae

Acetobacteraceae has garnered significant attention because of its unique properties and the broad applications of the bacterial cellulose it produces.However,unlike model strains,Acetobacteraceae have few synthetic biology applications because they are difficult to manipulate genetically and have insufficient genetic regulatory elements,among other factors.To address this limitation,this study characterized the fundamental properties and synthetic biology elements of three commonly used bacterial cellulose-producing strains.First,the basic characteristics of the three strains,including their cellulose film production ability,division time,antibiotic susceptibility,and plasmid features,were analyzed.Two inducible promoters(pTrc and pLux101)were subsequently characterized within the three strains.The inducibility of the pTrc promoter was relatively low across the three strains(induction ratio:1.98–6.39),whereas the pLux101 promoter demonstrated a significantly greater level of inducibility within the three strains(induction ratio:87.28–216.71).Finally,through gene knockout experiments,this study identified four genes essential for bacterial cellulose film production in the genome of the Gluconacetobacter hansenii ATCC 5358 strain.This study not only enriches the library of synthetic biology elements in nonmodel strains,but also lays the foundation for the synthetic biology applications of Acetobacteraceae.

玉米单倍体成株诱导率和加倍率研究

利用吉诱SM6278-2对31份不同种质基础材料进行单倍体杂交诱导,在三亚南滨农场基地进行自然加倍自交试验。结果表明,不同材料单倍体诱导成株率存在差异,差异不显著;单倍体诱导成株率最高达4.7%最低为0.3%平均为1.0%不同材料单倍体雄穗加倍率存在极显著差异,最高为47.1%最低为1.6%平均为16.7%不同材料单倍体结实株率存在极显著差异,最高为23.5%最低为0%平均为6.1%不同材料单倍体雄穗加倍形成的花粉亲和力差异极显著。单倍体雄穗加倍与自交结实密切相关,单倍体雄性的育性问题是单倍体自交结实性的关键因素。

Effects of 2,4-D and 6-BA on Callus Induction and Plantlet Regeneration from Mature Embryos of Hsien Rice

[ Objective] In order to study the effects of 2,4-D and 6-BA on callus cultivation from mature embryos of hsien rice. [ Method] 2,4-D and 6-BA were set at different concentrations in callus induction and differentiation mediums to study their effects on callus induction, seedling formation and regenerated seedlings rooting. [ Result] In the callus induction medium treated with 0.5 mg/L 2,4-D, the callus induction effects on the varieties like Jiayu 948, Yanghui 559, Yangxian 6547, Zhong＇erruanzhan, Minghui 86, Guanghui 998 and Zunxian 3 were the best; If 0.2 mg/L 6-BA was added into the callus induction medium containing the optimum level of 2,4-D, there was no obvious effect on induction rate of callus, but the differentiation and seedling of callus were inhibited; If the concentration of 6-BA was reduced appropriately in the differentiation medium, the seedling rate of callus would be not only no decreased but increased, meanwhile the quality of regenerated plants would be improved. [ Conclusion] The study results provided some references for the reasonable uses of 2,4-D and 6-BA in callus culture of hsien rice.

Callus induction from leaves of different paulownia species and its plantlet regeneration

The experiment was carried out on five different species of Paulownia for callus induction from leaves. MS medium was adopted as basic medium, and from different combinations of NAA and BA the suitable media were determined for callus induction, bud differentiation, and root differentiation of five different species. MS+0.5NAA+4BA, MS+0.3NAA+2BA, MS+0.5NAA+4BA, MS+0.3NAA+6BA, and MS+0.3NAA+8BA were suitable media of callus inductions of leaves, respectively, for Paulownia tomentosa, Paulownia australis, Paulownia fortunei, Paulownia elongata and P. tmentosa x P. fortunei, and MS+0.3NAA+12BA, MS+0.3NAA+12BA, MS+0.5NAA+12BA, MS+0.5NAA+12BA, and MS+0.7NAA+12BA were suitable media for bud differentiation from leaf callus respectively for above five species. The rooting media was determined as 2MS+0.1NAA, 1/2MS+0.1NAA, 1/2MS, 1/2MS+0.3NAA, and 1/2MS+0.5NAA. These results provide reference data for breeding new fine va-rieties with different kinds of Paulownia protoplasts fusions.

The BUD2 mutation affects plant architecture through altering cytokinin and auxin responses in Arabidopsis

The ratio of auxin and cytokinin plays a crucial role in regulating aerial architecture by promoting or repressing axillary bud outgrowth. We have previously identified an Arabidopsis mutant bud2 that displays altered root and shoot architecture, which results from the loss-of-function of S-adenosylmethionine decarboxylase 4 （SAMDC4）. In this study, we demonstrate that BUD2 could be induced by auxin, and the induction is dependent on auxin signaling. The mutation of BUD2 results in hyposensitivity to auxin and hypersensitivity to cytokinin, which is confirmed by callus induction assays. Our study suggests that polyamines may play their roles in regulating the plant architecture through affecting the homeostasis of cytokinins and sensitivities to auxin and cytokinin.

Activities of laccase produced by a strains Penicillium simplicissimum induced by chemical agentia and UV radiation

Penicillium simplicissimum was cultured and preserved on the potato dextrose agar(PDA)medium.PDA-RBBR(Remazal Brilliant Blue R)medium was used for the screening of the strains,which is able to produce enzymes.After the mutation process in Penicillium simplicissimum induced by chemical reagent and ultraviolet radiation,a high laccase-producing strains Penicillium simplicissimum was obtained.When 5 m L diethyl sulfate(2%)was mixed along with 5 m L spore suspension for 30 min,chemical mutagenesis reached its best condition.And the optimum conditions of UV mutagenesis were that spore suspension was irradiated for 4 min under 15 W UV lamp at a distance of 30 cm.The highest activity of C_5E_4 strains was 4.80 U/g over 18%higher than the maximum laccase activity of original microorganism.Five generations of the mutant strains were cultured,and the laccase activity of the strains was measured.The result showed that C_5E_4 strains can product laccase of the five subcultures stably.

Changes of NF-κB, Bax and Caspase 3 in Apoptosis Induced by Ligustrazine Combined with Cis-dichlorodiamine Platinum in Human Gastric Carcinoma SGC-7901 Cell Lines

[Objective] This study aimed to investigate the mechanism of apoptosis induced by ligustrazine(TMP) and cis-dichlorodiamine platinum(DDP) in SGC-7901 cell lines in vitro. [Methods] SGC-7901 cell lines were treated with ligustrazine and DDP alone or combined for 48 h for Western blot analysis, respectively. Western blot analysis was used to determine the expression of proteins involved in apoptosis including NF-κB p65, bax and caspase-3. [Results] The viability of SGC-7901 cells was inhibited after treated with ligustrazine and/or combined with DDP. The expression of NF-κB P65 protein decreased after treated with drugs, in which the protein decreased significantly in 1.2 mg/ml of TMP combined with 2 μg/ml of DDP group.Meanwhile, we investigated the protein expression of bax and caspase-3. The results showed that the expression of the two proteins increased following with the increasing concentration of TMP. [Conclusion] All the results indicated that ligustrazine combined with DDP could induce the apoptosis of SGC-7901 cell lines, and NF-κB maybe the possible way to induce the cell apoptosis.

Effect of Salinity Stress and Mutagenic Sodium Azide on Callus Induction and Plant Regeneration of Borage （Borago officinalis） in Vitro

The effect ofmutagenic NaN3 at concentration （0.0, 2.0 and 4.0 mM） and salinity stress at the levels （6.5, 8.5, 10.5 and 12 dS/m） on the seeds germination, callus induction and plant regeneration fi＇om stressed callus of different borage explants were investigated. The results showed that （4.0 mM） NaN3 with 4 h incubation period increased germination percentage reached 83.3% rate. Moreover the responses of different explants for callus induction in the presence of different combinations from auxin and cytokines were varied and a combination of（2 mg/L ）from each of BA and IAA gave high callus fresh weight reached （229.6, 218.0, 237.3） for （shoot tips, cotyledon leaves and hypocotyls） respectively .Concerning to the effect of salinity stress on callus induction and plant regeneration a high reduction in callus flesh weight and plant regeneration were observed at the high level of NaCl.

WWOX induces apoptosis and inhibits proliferation of human hepatoma cell line SMMC-7721

AIM: To investigate the effects of the WWOX gene on the human hepatic carcinoma cell line SMMC-7721. METHODS: Full-length WWOX cDNA was amplified from normal human liver tissues. Full-length cDNA was subcloned into pEGFP-N1, a eukaryotic expression vector. After introduction of the WWOX gene into cancer cells using liposomes, the WWOX protein level in the cells was detected through Western blotting. Cell growth rates were assessed by methyl thiazolyl tetrazolium (MTT) and colony formation assays. Cell cycle progression and cell apoptosis were measured by flow cytometry. The phosphorylated protein kinase B (AKT) and activated fragments of caspase-9 and caspase-3 were examined by Western blotting analysis. RESULTS: WWOX significantly inhibited cell proliferation, as evaluated by the MTT and colony formation assays. Cells transfected with WWOX showed significantly higher apoptosis ratios when compared with cells transfected with a mock plasmid, and overexpression of WWOX delayed cell cycle progression from G1 to S phase, as measured by flow cytometry. An increase in apoptosis was also indicated by a remarkable activation of caspase-9 and caspase-3 and a dephosphorylation of AKT (Thr308 and Ser473) measured with Western blotting analysis. CONCLUSION: Overexpression of WWOX induces apoptosis and inhibits proliferation of the human hepatic carcinoma cell line SMMC-7721.

Oxaliplatin and teniposide can inhibit the proliferation and induce the apoptosis of gastric cancer cell line BGC-823 synergistically

Objective:The aim of this study was to investigate the synergistic effects of oxaliplatin and teniposide on proliferation and apoptosis of gastric cancer cell line BGC-823.Methods:MTT assay was carried to examine the inhibition rate of oxaliplatin and teniposide on gastric cancer cell line BGC-823 with various concentrations separately and associatively.The apoptosis rate of BGC-823 cells under the treatment of oxaliplatin or/and teniposide was examined by flow cytometry.The expression level of livin, an apoptosis-associated protein, was explored by western blot.Results:Oxaliplatin or teniposide could remarkably inhibit the BGC-823 gastric cancer cell growth with a dose-response manner, separately and associatively.The inhibition rate of oxaliplatin combined with teniposide on BGC-823 cells was higher than that of single oxaliplatin or single teniposide(P < 0.05), with 0.46 as combination index(CI) value.The apoptosis rates of cells treated by oxaliplatin for 12 h, 24 h and 48 h were 6.13%, 13.86% and 21.48%, respectively, while which of teniposide were 4.60%, 10.72%, 17.07%.But when the two medicines were carried associatively, the apoptosis rates for 12 h, 24 h and 48 h were 11.73%, 24.14% and 44.75%, respectively.Western blot showed that the expression level of livin was more down-regulated when cells were treated by oxaliplatin + teniposide than by oxaliplatin singly.Conclusion:The combination of oxaliplatin and teniposide can exert a synergistic effect on gastric cancer cell BGC-823.

Effect of Different Hormone Combinations on Somatic Embryogenesis in Cotton Cultivar Xinluzao 33(Gossypium hirsutum L.)

[Objective] This study was conducted to evaluate the efficiency of somatic embryogenesis and plant regeneration for an upland cotton cultivar Xinluzao33 under the induction of different hormone combinations and thus to determine the optimal hormone combination. [Method] Calli of Xinluzao33(Gossypium hirsutum L.) were induced from seedling hypocotyl tissue by a range of DK and BK combinations. Embryogenic calli and embryos were induced on callus-inducing medium(CIM) without any hormones. Callus appearance and quality were compared to determine which medium was the optimal for callus induction. Embryogenesis ratio was calculated to determine which medium was the best for somatic embryogenesis and plant regeneration. [Result] Callus induction rate was 100% in all the 12 hormone combinations.The calli were yellow or kelly, and their texture was loose or soft under low concentrations of DK combinations, green or white, variably compact under high concentrations of DK combinations. The calli induced by BK combinations were kelly or green, covering creamy white substance. The best medium for callus induction was DK6(0.05 mg/L 2, 4-D and 0.10 mg/L KT). Embryogenic calli were successfully induced from all the combinations. The efficiency of embryogenic callus induction,embryogenesis, and plantlet regeneration were significantly different among the 12 combinations. The result showed that the embryogenesis ratio was the highest in BK3 combination(0.50 mg/L IBA and 0.50 mg/L KT), 72.86% of embryogenic calli differentiated into somatic embryos after being cultured on CIM for 80 d, and80.93% of the somatic embryos finally regenerated into plants on SEM(somatic embryo induction medium). [Conclusion] These results indicate that hormone combination BK3(0.50 mg/LIBA and 0.50 mg/L KT) was the best medium for somatic embryogenesis and plant regeneration from Xinluzao33.

Influences of antibiotics on plantlet regeneration via organogenesis in loblolly pine (Pinus taeda L.)

Three antibiotics ampicillin, carbenicillin, and cefotaxime were evaluated for their effects on induction, growth, and differentiation of organogenic calli, as well as rooting of regenerated shoots of three loblolly pine (Pinus taeda L.) genotypes. Of the antibiotics administered, cefotaxime maximally increased the frequency of callus formation and growth rate of organogenic calli, carbenicillin maximally increased the frequency of shoot regeneration and the average number of adventitious shoots per piece of organogenic callus, ampicillin maximally decreased the rooting frequency of regenerated shoots and mean number of roots per regenerated shoot, in comparison with antibiotic-free media. Compared with the control, ampicillin minimally increased the frequency of callus formation, cefotaxime minimally increased the frequency of shoot regeneration, and carbenicillin mini-mally decreased the rooting frequency of regenerated shoots in three loblolly pine genotypes tested. All three antibiotics in-creased the frequencies of callus formation and shoot regeneration, and reduced the rooting frequency of regenerated shoots suggested that the establishment of an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integra-tion of foreign genes into loblolly pine need to select a suitable antibiotic. This investigation could be useful for optimizing genetic transformation of conifers.

除草剂诱导玉米纯系选育新技术研究

以氟乐灵和炔苯酰草胺作为一种新的诱导剂,以不同遗传背景的玉米自交系及杂交种为试材,通过不同试剂、不同浓度、不同时期处理,进行化学诱导玉米孤雌生殖研究。结果表明,80μmol/L为氟乐灵和炔苯酰草胺的最佳诱导浓度,结实株率分别达到24.03%和36.36%;最佳处理时期在雌穗吐丝后第5天。杂交种的诱导效果普遍好于自交系及不同世代的材料,糯玉米好于普通玉米,Lancaster群好于Reid群。