香蕉枯萎病拮抗菌的筛选及其作用机制研究   总被引：15，自引：0，他引：15  

肖爱萍  游春平  梁关平  黄益燕 《植物保护》2006,32(4):53-56

通过分离和筛选,从香蕉园或者其他果园的土壤中分离获得13株对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)具有抑制作用的拮抗菌,并对部分拮抗菌抑制病菌菌丝生长和孢子萌发进行了试验。结果表明,拮抗菌株d4、d5、B3和p发酵液对香蕉枯萎病菌生长具有显著的抑制作用,在平板上产生的抑菌圈直径为21.75～34.75 mm,抑菌效果具有持续稳定性,对孢子萌发的抑制率为90.49%～97.18%;拮抗菌对病菌的作用表现为对菌丝的消融、菌丝细胞的泡囊化、抑制病菌分生孢子的萌发、孢子芽管的扭曲。  相似文献   

Comparison of S-RNase,RNase T₁, T₂, and A effects on growth inhibition and RNA degradation of in vitro-cultured pear pollen     

Shin Hiratsuka  Atsushi Hirano  Shao-Ling Zhang 《Scientia Horticulturae》2007

To obtain the basic information on fruit set regulation, effects of several RNases including S-RNase on pollen tube growth and RNA degradation in the tube were studied in the pear. Purified S-RNase from the Japanese pear ‘Kosui’ (S₄S₅) predominantly inhibited the growth of ‘Kosui’ pollen tubes (self) in vitro at 0.28 unit μL⁻¹, but it inhibited ‘Chojuro’ (S₂S₃) pollen (cross) only slightly. The same unit of RNase T₁ (EC 3.1.27.3) clearly inhibited the pollen tube growth, but the action was significantly weaker than that of the S-RNase against the self-pollen. Inhibitory effect of RNase T₂ (EC 3.1.27.1) and RNase A (EC 3.1.27.5) was only slight. The proteins other than the S-RNase extracted from pear style did not have any inhibitory action, though they possessed RNase activity 3.8 times higher than S-RNase. Thus, RNases tested here could not substitute for the S-RNase in specific inhibition against the self-pollen tube growth. Total RNA degradation by each RNase occurred in the pollen tubes as following order; S-RNase (self) ≥T₁ > T₂ ≥ A > S-RNase (cross). Degradation degree of 28S and 18S rRNA was as follows; S-RNase (self) > A > T₁ > T₂ > S-RNase (cross). The degradation of 5.8S and 5S rRNA was; S-RNase (self) > S-RNase (cross) > A > T₂ > T_1. The degree of rRNA degradation was, thus, not always in parallel with the degree of pollen growth inhibition. The S-RNase may degrade not only rRNA but also mRNA essential for pollen tube growth, and may be specifically adapted to inhibit the growth of self-pollen tubes. Therefore, controlling S-RNase amount in the style will produce self-thinning cultivars efficiently, which are unnecessary not only for hand-pollination but fruit-thinning practices in the pear. Practically, cultivar with weak self-incompatibility and small amount of S-RNase, such as ‘Okusankichi’, may be an expecting candidate for breeding self-thinning cultivars.  相似文献   

我国出口观赏鸟新城疫病毒血清抗体的监测     

陈永红李国清  梁刚陈敏健  苏遂琴张云桥 《中国动物检疫》2004,21(1):23-24

2001年月11月-2002年12月间，用血凝抑制试验(HI)对28种出口观赏鸟的600份血清进行了NDV血清抗体监测。结果：阳性抗体1：2滴度的检出率为69．8％、1：4的为15．3％、1：8(含1：8以上)的为4．8％；冬春两季的检出率比夏秋两季高。被检雀形目的10个科28种观赏鸟中全部检出不同程度的NDV血清阳性抗体，抗体滴度在1：4以上的有9个科，分别是雀科、梅花雀科、绣眼科、鸫亚科、鹎科、巫鸟科、书眉画科和百灵科，其中以梅花雀科和百灵科的检出率最高。  相似文献   

盐酸小檗碱与左氧氟沙星联合抑制MRSA及其机制研究     

操庆国  郭钦  彭凯  蔡佳惠  任成万  李昀庭 《畜牧兽医学报》2022,53(9):3208-3220

养殖场抗生素滥用造成多种耐药性细菌的产生,从奶肉类制品中分离出耐甲氧西林金黄色葡萄球菌（MRSA）的案例逐年增长,对养殖业食品安全造成巨大威胁。本研究筛选出与左氧氟沙星具有联合抑制MRSA效果的天然产物盐酸小檗碱（BBR）,探究BBR与其对MRSA的协同抑菌效果和联合抑菌机制。结果表明,BBR能有效抑制MRSA生长,提高MRSA对左氧氟沙星的敏感度,两者联用后,MRSA对左氧氟沙星的MIC降为之前的1/16。协同作用机制主要为上调ribA及下调mec A和msc L表达水平,破坏细胞壁、增加细胞膜的通透性,从而达到协同抑菌的目的。本研究有助于降低畜牧养殖中抗生素的使用,为提高肉奶类食品安全奠定基础。  相似文献   

乳酸菌发酵驼乳工艺优化及抑制α-淀粉酶和α-葡萄糖苷酶活性的研究     

买尔哈巴  艾合买提  曹英  崔卫东  陈钢粮  侯新强  薛杉  侯敏 《中国乳业》2022,(8):97-107

[目的]以实验室前期从驼乳中分离得到的乳明串珠菌、副干酪乳杆菌为对象,并通过体外实验对发酵驼乳抑制α-淀粉酶和α-葡萄糖苷酶活性以及抗氧化能力进行测定。[方法]以α-淀粉酶抑制率和α-葡萄糖苷酶抑制率为考察指标,在单因素试验的基础上,采用正交试验优化发酵驼乳的参数条件。测定在不同储藏时间下试验组乳明串珠菌、副干酪乳杆菌发酵驼乳、对照组乳明串珠菌、副干酪乳杆菌发酵牛乳和嗜热链球菌、保加利亚乳杆菌发酵驼乳pH值、酸度、活菌数、α-淀粉酶抑制率、α-葡萄糖苷酶抑制率、羟自由基和超氧阴离子自由基清除率的变化。[结果]驼乳发酵的最佳工艺条件为乳明串珠菌∶副干酪乳杆菌比例2∶3、接种量2%、发酵温度39 ℃,发酵时间24 h,此条件下测得对α-淀粉酶和α-葡萄糖苷酶的抑制率分别达到87.20%和20.85%,与未优化前相比,α-淀粉酶的抑制率提高14.10%,α-葡萄糖苷酶抑制率提高4.4%。在4 ℃储藏期间发酵驼乳α-淀粉酶抑制率在第6d时最高为90.39%,对α-葡萄糖苷酶的抑制率最高为36.32%,抑制率显著高于对照组。各组对羟自由基的清除率达到70%以上,最高为94.91%,超氧阴离子自由基清除率最高达到78.10%,整个测定过程中试验组的抗氧化活性均显著高于对照组。[结论]经乳酸菌发酵驼乳抑制α-淀粉酶和α-葡萄糖苷酶活性提高,在储藏期间抗氧化活性显著高于对照组（P<0.05）。  相似文献   

Antiproliferative activity of Goldfussia psilostachys ethanolic extract on K562 leukemia cells     

Gao X  Zhang G  Zhou M  Luo D  Li B 《Fitoterapia》2004,75(7-8):639-644

A dose-dependent and significant (P<0.01) antiproliferative effect of Goldfussia psilostachys ethanolic extract was observed on K562 cells. The IC(50) is ca. 0.5 microg/ml. The extract markedly increases the proportion of cell in G2/M phases and decreases the population of cells in G0/G1 phases. Moreover, the antimitotic effect is correlated with polymerization of microtubule assembly. These results indicate that G. psilostachys ethanolic extract inhibits the proliferation of K562 cells and disrupts the normal dynamic of microtubules during mitosis.  相似文献   

9种中药成分对猪传染性胃肠炎病毒体外增殖的抑制作用   总被引：1，自引：0，他引：1  

张为民  胡蓉  郭抗抗  宁蓬勃  张彦明  卿素珠 《中国兽医学报》2015,35(5):799-803

运用MTT法结合细胞病变方法测定黄芩苷、穿心莲内酯、大黄素、大黄酸、芦荟大黄素、大黄素甲醚、苦参碱、氧化苦参碱和苦马豆素9种中药成分对猪传染性胃肠炎病毒(TGEV)在ST细胞上增殖的抑制作用,实时荧光定量PCR(Real-time PCR)进一步检测黄芩苷对TGEV在ST细胞上增殖的抑制作用。结果显示,9种中药成分在体外对TGEV在ST细胞上的增殖均有一定的抑制作用,其中黄芩苷对TGEV的生物合成、吸附保护和直接灭活作用的抑制率分别为58.23%、88.12%和100.00%;Real-time PCR检测黄芩苷3种给药方式均能在转录水平显著降低TGEV mRNA的相对表达量,与病毒对照组相比差异极显著(P0.01)。结果表明,9种中药成分在体外对TGEV在ST细胞上的增殖均有一定的抑制作用,以黄芩苷作用最好。  相似文献   

Propanil and swep inhibit 4-coumarate:CoA ligase activity in vitro   总被引：1，自引：0，他引：1  

Yun MS  Chen W  Deng F  Yogo Y 《Pest management science》2007,63(8):815-820

4-Coumarate:CoA ligase (4CL, EC 6.2.1.12) in the phenylpropanoid pathway in plants has attracted interest as a novel target for developing effective plant growth inhibitors (PGIs). In a previous study in which the 4CL inhibitory activity of 28 existing herbicides was investigated using an optimized in vitro screening assay, 4CL activity was found to be strongly inhibited by propanil and swep at 100 microM. Here, further experimental evidence is provided to substantiate the previous result. Using 4-coumaric acid as substrate, tobacco 4CL activity was inhibited by propanil or swep in a concentration-dependent manner, with 50% inhibition concentrations (I(50)) of 39.6 and 6 microM respectively. These herbicides also exhibited uncompetitive inhibition towards 4-coumaric acid. Furthermore, 4CLs from several plant species were inhibited by the herbicides within a range from 1 to 50 microM. It is proposed that these herbicides have another site of action as a result of the inhibition of 4CL in the phenylpropanoid pathway, and this enzyme represents a new target site for the development of PGI.  相似文献   

碱提甘蔗皮多糖提取工艺、初步结构及其对α-葡萄糖苷酶的抑制作用     

王萱萱  刘春宇  谢贝昱  张淑淑  王丹阳  朱振元 《中国农业科学》2021,54(12):2653-2665

【目的】建立碱提甘蔗皮多糖的优化工艺,进一步探究其结构特征,并评价其对α-葡萄糖苷酶的抑制作用。【方法】采用单因素试验和响应面分析法（RSM）对碱提甘蔗皮多糖（SPAP）提取工艺进行优化,采用苯酚硫酸法测定多糖含量。SPAP经Sevag法除蛋白、AB-8除色素后进行结构表征,主要包括高效液相色谱法（HPLC）检测多糖分子量分布,气相-质谱色谱仪（GC-MS）进行单糖分析及傅里叶红外光谱仪（FT-IR）对官能团进行分析。采用4-硝基苯基-D-吡喃葡糖苷（PNPG）法测定多糖提取物对α-葡萄糖苷酶抑制作用。【结果】SPAP的最佳提取条件为提取温度37℃、氢氧化钠（NaOH）浓度5%、料液比1∶46（g·mL^-1）、提取次数4次,在此条件下SPAP得率达到10.84%。经除蛋白、色素后,SPAP含量达到86.54%,主要由阿拉伯糖、木糖、葡萄糖和半乳糖4种单糖组成,分子量为3.03×10³ kD,可能为吡喃型杂多糖,呈现α或β构型。此外,SPAP表现出良好的α-葡萄糖苷酶抑制作用,其抑制率达到78.31%。【结论】对碱提甘蔗皮多糖进行工艺优化,可有效利用原料、提高产出和效率;由HPLC、FT-IR、GC-MS等方面初步阐述了SPAP的结构特性,同时SPAP对α-葡萄糖苷酶表现出良好的抑制作用,具有一定的降糖潜力,研究结果为进一步研究SPAP的构效关系提供了理论依据。  相似文献   

Inhibition of protease activities in discus Symphysodon spp. by three plant meals     

Alexander Chong  Roshada Hashim  Ahyaudin Bin Ali 《Aquaculture International》2002,10(5):433-441

Based on biochemical assays and electrophoretical methods, the inhibitory effects of three plant meals (soybean meal, wheat meal, winged bean meal) on digestive alkaline proteases of discus were investigated. Casein assays revealed that increasing levels of soybean meal caused a linear inhibitory effect on activity of protease. SDS-PAGE images revealed that trypsin and chymotrypsin were the inhibited enzymes. Soybean showed the lowest inhibition rate followed by wheat meal and raw winged bean. There was a quadratic relationship between wheat meal levels and its inhibition of protease acitivity. The highest inhibitory effect was obtained with the winged bean meal with inhibition of caseinolytic activities ranging from 3.6–98.6%. Results from this study showed the potential of both soybean meal and wheat meal as ingredients for practical diet for discus, while demonstrating the need for further improvement in processing method for winged bean meal.  相似文献