腐植酸对番茄苗期氮素代谢的影响

腐植酸对肥料具有改性增效的作用,以番茄为供试材料,研究腐植酸增效剂不同添加量对番茄苗期生长及氮素代谢酶活性的影响,为腐植酸的开发应用提供参考依据。采用砂培试验方法,设置了向霍格兰营养液分别加入腐植酸增效剂0(HA0),1(HA1),2(HA2),5(HA3),10(HA4) mL/L处理。培养30天后,测定番茄的生长指标、植株养分含量、硝酸还原酶活性、谷氨酰胺合成酶和谷氨酸脱氢酶活性。添加适量腐植酸增效剂能促进番茄苗期生长,HA3处理番茄根系干重比HA0提高了31.68%,HA1处理番茄地上部干重最大。添加腐植酸可以提高番茄苗期叶片叶绿素含量,HA3处理番茄苗期叶片叶绿素总量和类胡萝卜素含量最高,分别比HA0提高了17.11%,24.04%。添加适量腐植酸增效剂能增加番茄苗期根系和地上部对氮素的吸收,HA3处理的番茄根系、地上部及总氮素积累量比HA0分别提高了30.61%,20.24%,21.54%。添加腐植酸增效剂可以调控番茄根系和叶片氮素代谢过程,提高了氮素代谢酶活性,与HA0相比,HA4处理根系硝酸还原酶活性最大,HA3处理根系谷氨酰胺合成酶活性最高,HA2处理根系谷氨酸脱氢酶的活性最大;HA3处理番茄苗期叶片中硝酸还原酶、谷氨酰胺合成酶和谷氨酸脱氢酶活性最大,与HA0处理相比分别提高了38.27%,64.54%,106.63%。添加腐植酸增效剂可以促进番茄苗期的生长和对氮素的吸收,提高氮素代谢酶活性,处理中以在营养液中添加5 mL/L腐植酸增效剂效果最佳,腐植酸增效剂添加量低于5 mL/L时,对番茄苗期的生长及氮素代谢具有明显的促进作用。     

橘小实蝇谷氨酸脱羧酶的生化及分子特性

【目的】在测定橘小实蝇（Bactrocera dorsalis）γ-氨基丁酸（GABA）含量和谷氨酸脱羧酶（GAD）活性的基础上,克隆获得橘小实蝇GAD基因（BdGAD1）全长序列,进一步解析GABA、GAD以及BdGAD1在橘小实蝇各发育阶段、成虫不同体段以及经阿维菌素刺激后的表达模式,分析橘小实蝇GAD对阿维菌素作用的应激反应,为系统解析GABA介导的阿维菌素抗药性机制提供基础数据。【方法】采用高效液相色谱法测定橘小实蝇体内GABA含量,分析阿维菌素刺激对GABA含量的剂量和时间效应;以谷氨酸为底物,采用微量滴度酶标板法测定橘小实蝇经阿维菌素刺激后GAD活力的变化;通过同源序列比对的方法,从橘小实蝇转录组数据中筛选出1条GAD基因片段,利用cDNA末端快速扩增技术（RACE）获得该基因的全长cDNA序列;应用生物信息学分析软件对该基因的开放阅读框、编码的氨基酸序列、分子量等信息进行预测,并基于最大似然法构建该基因与其他昆虫相关基因序列的系统发育树,明确其系统进化关系。此外,分别提取橘小实蝇各发育阶段和成虫不同体段的RNA,以表达稳定的α-Tubulin为内参基因,应用qPCR技术,解析BdGAD1在橘小实蝇各发育阶段（卵、幼虫、蛹和成虫）和成虫不同体段（头、胸、腹）以及经阿维菌素刺激后的表达模式。【结果】经阿维菌素刺激后,橘小实蝇体内GABA含量升高,且与阿维菌素剂量及处理时间呈正相关,暗示橘小实蝇可能通过调节GABA含量以抵御阿维菌素的毒害。同时,橘小实蝇体内GAD的比活力也随药剂剂量增加而升高。通过RACE扩增,获得了橘小实蝇BdGAD1的cDNA全序列,长度1 755 bp,开放阅读框1 197 bp,编码398个氨基酸,GenBank登录号为KC763804。基于最大似然法构建的系统发育树显示,该基因编码的蛋白质与冈比亚按蚊的GAD亲缘关系最近,序列一致性高达97%。qPCR分析结果表明,BdGAD1在幼虫期表达量最高,不同体段间相比较发现该基因在成虫腹部的表达量最高。经阿维菌素刺激后,BdGAD1表达水平上调。【结论】BdGAD1的表达具有发育阶段和体段特异性。阿维菌素能够刺激橘小实蝇体内BdGAD1表达水平上升,进而引起GAD活力增加促使虫体合成产生大量的GABA,这可能是橘小实蝇抵御阿维菌素毒害甚至产生抗药性的原因。     

Reduced Response to Intravenous Endotoxin Injections Following Repeated Oral Administration of Endotoxin in the Pig

Three prepubertal gilts were each given 100 mg of endotoxin (ET) in their ordinary feed rations, twice daily for 6 days; 3 other gilts received standard feed. Following ET feeding, all animals were injected intravenously (i.v.) with ET (1.0 µg/kg b.w.) once daily for 5 days. Blood samples were collected and analysed for hematology and total serum bile acids (S-BA), glutamate dehydrogenase (S-GLDH), calcium (S-Ca), iron (S-Fe), zinc (S-Zn) and a blood plasma metabolite (15-ketodihy-dro-PGF2a; P-PG) of prostaglandin F2a. The animals showed no apparent clinical symptoms following ET-feeding, neither did the blood analyses reveal effects of oral ET. However, when iv ET injections were given, the ET-fed animals showed fewer clinical signs of endotoxemia following the 2nd to 5th injection. S-BA and S-GLDH increased markedly in the standard-fed group following the first injection, while the ET-fed animals showed a much smaller increase in S-BA and no change in S-GLDH on that day. The difference in response may be explained by a direct uptake of ET from the gastrointestinal tract in the ET-fed pigs, making them less sensitive to the injected ET     

损毁弓状核对大鼠骨微构筑学的影响

目的研究损毁大鼠下丘脑弓状核(ARC)对骨微构筑学的影响。方法新生雌性Sprague-Dawley(SD)大鼠12只,用同窝对照的方法,按体质量从轻到重编号,用抽签法随机分为实验组和对照组,每组6只。实验组大鼠于出生后第1、3、5、7、9天皮下注射10%谷氨酸单钠(MSG)4g/kg B.W,对照组同法注射等体积生理盐水。各组大鼠皆存活至200d,以3%戊巴比妥钠腹腔麻醉,用4%多聚甲醛经左心室行全身灌注,取脑作下丘脑弓状核冠状面切片,HE染色。取各组大鼠左侧胫骨,用2.5%戊二醛固定,然后将胫骨近端作矢状面锯开,用作扫描电镜研究。另取右侧胫骨和第四腰椎,常规脱钙,石蜡包埋,矢状面连续切片,胶原特殊染色,用于显示骨小梁结构。用图象分析仪对弓状核正中隆起切面和骨组织进行照片和计量。结果MSG大鼠弓状核神经细胞数量显著减少,骨的微构筑学出现明显破坏,发生了明显骨质疏松。结论(1)损毁大鼠下丘脑弓状核可导致骨微构筑学明显破坏,出现明显骨质疏松,首次命名为大鼠脑源性骨质疏松。(2)ARC参与骨代谢的调控。     

Research on Glutamate Synthase Activity in Sugar Beet (Beta Vulgaris L.) under Different Levels of Nitrogen

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Protective Effects of Marine Alkaloid Neolamellarin A Derivatives against Glutamate Induced PC12 Cell Apoptosis

Marine alkaloids obtained from sponges possess a variety of biological activities and potential medicinal value. The pyrrole-derived lamellarin-like alkaloids, especially their permethyl derivatives, show low cytotoxicity and potent MDR reversing activity. Neolamellarin A is a novel lamellarin-like alkaloid which was extracted from marine animal sponges. We reported the synthetic method of permethylated Neolamellarin A and its derivatives by a convergent strategy in 2015. In 2018, we reported the synthesis and the neuroprotective activity in PC12 cells of 3,4-bisaryl-N-alkylated permethylated Neolamellarin A derivatives. In this report, another series of 15 different 3,4-bisaryl-N-acylated permethylated Neolamellarin A derivatives were synthesized, and the outstanding protective effects of these compounds against glutamate induced PC12 cell apoptosis were presented and discussed. These Neolamellarin A derivatives which possessed low cytotoxicity and superior neuroprotective activity may have the potential to be developed into antagonists against glutamate induced nerve cell apoptosis.     

La(Ⅲ)对UV-B辐射下大豆幼苗氨同化活性的影响

以水培大豆为试材，研究了模拟增强紫外辐射UV-B（280-320nm）对大豆幼苗叶片GS、GOGAT、GDH酶活性以及谷氨酸、谷氨酰胺和总游离氨基酸含量的影响，并研究了La（Ⅲ）对UV-B辐射伤害大豆幼苗的缓解效应。结果显示，高（0．45J·m^-2·s^-1）低（0．15J·m^-2·s^-1）两个紫外强度剂量下，叶片GS、GOGAT酶活性较对照组显著下降25．9％和11．3％，GOGAT降幅达34．7％和12．6％；经La（Ⅲ）预处理后各组下降幅度都有所减缓，Gs降幅为23．1％和7．9％，GOGAT为31％和7．8％，表明La（Ⅲ）对UV-B辐射伤害下，GS、GOGAT酶活性的下降有一定的缓解作用。GDH酶活表现为低强度促进（＋30．4％）高强度抑制（-12．8％），且La（Ⅲ）预处理组酶活相应升高，分别为＋47％和-9％，三指标连续11d的动态测定结果显示，La（Ⅲ）预处理组酶活性比相应单一UV—B处理组酶活性始终要高，表明适宜浓度的La（Ⅲ）能够提高植物GS、GOGAT和GDH的活性，增强植物氨同化能力，减轻UV-B胁迫对植物造成的伤害。     

Nitrogen Assimilatory Enzymes and Amino Acid Content in Inoculated Foliar Fertilized Pea Plants Grown at Reduced Molybdenum Concentration

ABSTRACT

A possibility to improve nitrogen assimilation in nitrogen fixing Molybdenum (Mo) deficient pea plants was shown. The influence of foliar supplied nutrients in addition to root nutrition resulted in reducing the unfavorable effects of inorganic nitrogen on nodule function and Mo deficiency on the nitrogen assimilatory enzymes. Inoculated pea plants were grown on liquid nutrient solution both with and without Mo. The following variants were tested: Mo supplied plants with root nutrition (F1 + Mo); Mo supplied plants with root and foliar nutrition (F2 + Mo); Mo deficient plants with root nutrition (F1 ? Mo); and Mo deficient plants with root and foliar nutrition (F2 ? Mo). Foliar application of nutrients had a positive effect on the glutamine synthetase and glutamate synthase enzyme activities in the roots and nodules of Mo deficient plants. It was found that the foliar fertilization reduced the inhibitory effect of Mo shortage on the aspartate/asparagine content in the pea shoots.     

Prospects of monosodium glutamate use for enhancement of spinosad toxicity against codling moth neonates

It was demonstrated that neonates of the codling moth,Cydia pomonella (L.), feed on ‘Red Delicious’ apple leaves and successfully molt to the second instar. Next, using a non-choice bioassay, we targeted codling moth neonates feeding on apple leaves, with standard concentrations of a culinary taste enhancer, monosodium glutamate (MSG), and Success®, which contains 22.8% spinosad as its active ingredient. The addition of 25 ppm MSG increased feeding by 20–30%. Stimulatory properties of MSG were preserved in the presence of 12.5 ppm Success, and mortality from a 12.5 ppm Success + 25 ppm MSG combination increased by factors of 3.1–1.6 compared with Success alone. In a field experiment without rain, MSG maintained its stimulatory properties for 24 h, increasing feeding by 37%. Consistently, without rain, MSG increased the toxicity of Success in the field by a factor of × 3.5. However, the stimulatory properties of MSG dropped to 19% with 4.3 mm of rain, and to zero with 9.6 mm of rain. Increased Success toxicity by MSG was reduced to × 1.6 with 4.3 mm of rain, and dropped to zero after 9.6 mm of rain. It is concluded that MSG seems to be a promising feeding stimulant, enhancing the toxic properties of Success which itself is a good candidate for codling moth control. However, field persistence of MSG needs to be improved, either by formulating the Success + MSG combination into some field-stable matrix, or by employing a sparingly water-soluble substance mimicking MSG’s action as a feeding stimulant in codling moth neonates.     

味精废水母液对嗜酸性酵母菌生长及有机质降解影响因素分析

研究了味精废水母液的稀释倍数、pH值、摇床转速、(NH4)2SO4浓度及葡萄糖浓度处理对酵母菌生长和降解有机质能力的影响.结果表明,母液稀释5倍,pH值3.5,250 r.min-1培养20 h,最大生物量(干重)为8 g.L-1,COD(化学需氧量)去除率为80.2%;高浓度(NH4)2SO4对酵母菌生长和降解有机质能力有一定的抑制作用,添加葡萄糖能促进酵母菌生长和提高有机质降解能力.