Extracts of killedPenicillium chrysogenum Induce resistance against Fusarium wilt of melon

Dry fungal biomass ofPenicillium chrysogenum (dry mycelium), a waste product of the pharmaceutical industry, was extracted with water and applied to the roots of melon plants before or after inoculation withFusarium oxysporum f.sp.melonis (Font). Seedlings (4–6 days after emergence) treated with either acidic dry mycelium extract (DME) or neutralized dry mycelium extract (NDME) were protected against challenge infection withFom. A single drench with 2–5% DME applied 12–72 h before inoculation provided significant control of the disease compared with water-drenched, challenged seedlings. No protection was seen in plants treated 0–6 h before inoculation or 0–48 h after inoculation. Neither DME nor NDME (0.5–5%) had any effect on fungal growthin vitro, which implied that disease controlin vivo was mediated by induced resistance. The resistance induced by DME protected melon plants not only against race 1,2, but also against the three other races of the pathogen, indicating a race-non-specific resistance againstFom. Both DME and NDME significantly increased peroxidase activity and free L-proline content in seedlings 12 h and 48 h after soil drench, respectively. Resistance to Fusarium wilt was significantly associated with elevated levels of peroxidase activity but not with free L-proline content. Thus, peroxidase might be involved in the defense mechanisms activated by DME or NDME. http://www.phytoparasitica.org posting Aug. 31, 2001.     

余甘子对强致癌物N-亚硝基化合物在人体内合成的阻断作用

本文采用Ohshima的方法,以尿中N-亚硝基脯氨酸(NPRO)量为指标,研究了余甘子果汁阻断人体内N-亚硝基化合物(NNC)的合成。12名志愿者摄入L-脯氨酸500 mg和硝酸钠300 mg后,尿中NPRO的量平均为75.10 nmol,而当摄入上述两种药物的同时,分别给予同浓度的抗坏血酸和余甘子果汁后,尿中NPRO的含量则分别降为41.08 nmol和20.79nmol,且后者此本底值(25.55 nmol)还低。表明在本实验条件下,摄入含抗坏血酸75mg的余甘子果汁13ml,即能完全阻断500mg L-脯氨酸和300mg硝酸钠在人体内所引起的NPRO的合成。同时也证明,余甘子果汁能有效地阻断人体内NNC的合成。     

Factors influencing tissue culture responses of mature seeds and immature embryos in turf-type tall fescue

In an effort to optimize tissue culture responses of turf‐type tall fescue for genetic transformation, the effects of five culture medium supplements on tissue culture responses were investigated with immature embryos and mature seeds of an elite cultivar, ‘Coronado’, as explant tissues. For both explants, calli induced on 6‐benzylaminopurine (BAP)‐containing medium had significantly improved regeneration ability. The optimal concentration of BAP for the induction of regenerable callus from mature seeds was 0.1 mg/l. Thidiazuron also improved callus regeneration frequency of mature seeds. Casein hydrolysate, L‐proline and myo‐inositol improved callus induction of immature embryos but not mature seeds. They did not improve callus regeneration frequencies with either explant tissue. By simply slicing the mature seeds into two halves longitudinally, the callus induction frequencies, as well as the corresponding overall plant regeneration frequencies, were increased approximately three‐ to six‐fold in all three combinations of 2,4‐dichlorophenoxyacetic acid and BAP in callus induction media.     

L-脯氨酸对枯草芽胞杆菌NCD-2菌株生物膜形成的影响

 枯草芽胞杆菌 NCD-2菌株在棉花品种‘冀棉11'根际的定殖能力与其根系分泌物中的L-脯氨酸相关。本研究通过外源添加L-脯氨酸评价其对NCD-2菌株生长量和生物膜形成的影响。结果表明,在MSgg培养基中添加L-脯氨酸培养48 h后对菌株生长不存在显著影响。采用称重法测定生物膜的湿重和干重,结果表明在MSgg培养基添加L-脯氨酸显著增加了生物膜产量,且生物膜的褶皱程度和立体结构变得更为明显。采用结晶紫染色法进行生物膜的定量测定发现,浓度为1.250～10.000 mg·mL^-1的L-脯氨酸可以显著提高菌株生物膜形成能力,而低浓度0.625 mg·mL^-1 的L-脯氨酸对生物膜形成无影响。通过RT-qPCR检测了NCD-2菌株生物膜形成相关基因tasA和epsA表达量的变化,结果表明,添加上述不同浓度L-脯氨酸能够显著提高tasA基因表达量,提高了2.53~9.98倍。除了浓度为0.625 mg·mL^-1 L-脯氨酸可提高epsA基因表达外,其他浓度没有显著改变epsA基因的表达,而且epsA基因表达量低于tasA基因。综合分析表明,L-脯氨酸促进NCD-2菌株生物膜形成不是通过改变菌株生长量,而是诱导tasA基因的表达产生更多的胞外蛋白TasA。     

L-脯氨酸在离子交换纤维上的吸附性能研究

[目的]为离子交换纤维(IEF)在L-脯氨酸吸附分离上的应用提供试验基础和理论依据。[方法]采用自制的强酸IEF吸附L-脯氨酸,通过静态吸附试验和动态吸附试验研究了L-脯氨酸在IEF上的吸附特点和影响因素。[结果]强酸IEF对L-脯氨酸具有很好的吸附能力。强酸IEF对L-脯氨酸的静态吸附在200 s内达到平衡,其吸附速率明显高于732树脂。强酸IEF的动态吸附量与L-脯氨酸的进口液浓度和流速有关。当L-脯氨酸溶液为3.57 g/L,其动态吸附量达185.68 mg/L。氨水可解吸交换柱上吸附的L-脯氨酸,再生后IEF仍具有较好的吸附性能。[结论]用强酸IEF富集分离L-脯氨酸有利于降低能耗、提高效率。     

Single and combined effects of colchicine, L-proline and post-inoculation low temperature on anther culture of wheat, Triticum aestivum L.

This investigation was undertaken to study the effects of colchicine, L-proline and a post-inoculation cold temperature of 14°C for 7 days, either as a single or as combined treatments, on the parameters of anther culture of the DH83Z118.32 wheat genotype. Results indicate that the addition of 100 mg/1 colchicine to the induction medium for a period of 3 days and at an incubation temperature of 28°C yielded the highest success index. This treatment, although it significantly reduced embryogenesis, improved embryoid quality so that not only the total regeneration, but also the percentage of green plantlets increased significantly, In addition, it raised the percentage of doubled haploids and, consequently, led to a significantly better final success index. Combining the colchicine treatment with a reduced post-inoculation temperature did not intensify its beneficial effect, although a treatment of reduced temperature alone was superior to normal temperature (28°C) for most parameters studied. The beneficial effects of adding L-proline (200 mg/1) to the induction medium, combined with a low temperature (10°C for 4 days) treatment, were diminished when this treatment was combined with a colchicine treatment.     

余甘子对强致癌物N-亚硝基化合物在人体内合成的阻断作用

本文采用Ohshima的方法,以尿中N-亚硝基脯氨酸(NPRO)量为指标,研究了余甘子果汁阻断人体内N-亚硝基化合物(NNC)的合成。12名志愿者摄入L-脯氨酸500mg和硝酸钠300 mg后,尿中NPRO的量平均为75.10nmol,而当摄入上述两种药物的同时,分别给予同浓度的抗坏血酸和余甘子果汁后,尿中NPRO的含量则分别降为41.08nmol和20.79nmol,且后者此本底值(25.55 nmol)还低。表明在本实验条件下,摄入含抗坏血酸75mg的余甘子果汁13ml,即能完全阻断500mg•L^-脯氨酸和300mg硝酸钠在人体内所引起的NPRO的合成。同时也证明,余甘子果汁能有效地阻断人体内NNC的合成。     

谷氨酰胺对草鱼肠道L-亮氨酸、L-脯氨酸吸收及肠道蛋白质合成的影响

利用肠道离体灌注模型和同位素示踪技术,研究谷氨酰胺对草鱼肠道L-亮氨酸和L-脯氨酸吸收量、肠道组织游离亮氨酸和脯氨酸量、以及对肠道蛋白质合成量的影响。结果表明:谷氨酰胺能够显著增加草鱼肠道对两种氨基酸的吸收量,显著增加肠道组织游离亮氨酸和脯氨酸量,并显著增加肠道蛋白质的合成量;将1.0mmol/L组与5.0mmol/L组谷氨酰胺的试验结果相互比较,无论是肠道吸收总量还是肠道组织游离氨基酸、新蛋白质合成量均没有显著差异;草鱼肠道在吸收亮氨酸和脯氨酸的同时,能够利用吸收的亮氨酸和脯氨酸和肠道蛋白质周转的氨基酸合成新的蛋白质,蛋白质合成量随着亮氨酸和脯氨酸浓度增加呈线性增加关系。本文结果表明,谷氨酰胺能够显著增加草鱼肠道对亮氨酸和脯氨酸的吸收量、能够显著增加肠道蛋白质的合成代谢。     

枯草芽孢杆菌NCD-2对棉花根系分泌物L-脯氨酸响应的转录-蛋白质组学联合分析

【目的】棉花根系分泌物L-脯氨酸是影响生防菌株定殖的关键因素之一,前期研究发现L-脯氨酸能够提高枯草芽孢杆菌（Bacillus subtilis）NCD-2生物膜形成能力。通过高通量测序技术分析L-脯氨酸调控枯草芽孢杆菌NCD-2生物膜形成和生防潜力相关的基因,为深入认识棉花根系分泌物与生防菌株的分子互作关系打下基础。【方法】以枯草芽孢杆菌NCD-2菌株为供试材料,外源添加浓度为10 mg·mL^-1的L-脯氨酸共培养24 h后,分别进行转录组（RNA-seq）和同位素标记相对定量蛋白质组技术（iTRAQ）分析,对所获得的转录组和蛋白质组数据进行生物信息学分析,利用实时荧光定量PCR（RT-qPCR）验证不同代谢通路中部分差异基因的表达情况。 【结果】转录组分析发现,L-脯氨酸和NCD-2菌株共培养后,获得1 071个差异表达基因（DEG）,其中602个基因上调,469个基因下调。GO分析发现在生物过程、细胞组分和分子功能方面分别有49、14和30个功能条目显著富集。KEGG代谢通路主要富集在化合物代谢、鞭毛组装、细菌运动和趋化作用。蛋白质组学分析发现,筛选到211个差异表达蛋白（DEP）,其中118个蛋白上调,93个蛋白下调。GO分析发现在生物过程和分子功能方面分别有13和8个功能条目显著富集。KEGG代谢通路主要富集在氨基酸代谢、碳水化合物类代谢、鞭毛组装和ABC转运蛋白。进一步转录-蛋白质组学联合分析发现,在L-脯氨酸作用下,检测到共有的显著差异表达基因（或蛋白）112个,其中38个基因（或蛋白）下调,74个基因（或蛋白）上调。GO功能显著富集主要集中在营养库活性、催化活性、细胞膜、定位、细胞脂质代谢过程、氧化还原过程、sigma因子活性、转运活性、芽孢形成9个方面。KEGG代谢通路主要富集在能量代谢、ABC转运蛋白、抗生素生物合成、鞭毛组装、运动或趋化作用和双组分系统方面。RT­qPCR验证了26个差异表达显著基因,结果发现在表达量上存在一定的差异,但表达趋势与RNA­seq和iTRAQ组学分析结果基本一致。【结论】棉花根系分泌物L-脯氨酸与枯草芽孢杆菌NCD-2之间的互作存在一个复杂的生物过程,依赖于不同代谢通路网络中的多个基因。双组分系统、抗生素生物合成、能量代谢、运动或趋化作用、鞭毛组装和ABC转运蛋白通路中的差异基因（或蛋白）可能在棉花根系分泌物与枯草芽孢杆菌互作过程方面发挥着重要作用。