Synthesis of active oryzacystatin I in transgenic potato plants

Summary Transformation of potato (Solanum tuberosum L.) with cysteine proteinase inhibitor (PI) genes represents a potential way of controlling the major insect pest Colorado potato beetle (CPB; Leptinotarsa decemlineata Say). The present study describes the Agrobacterium-mediated transformation of potato (cv. Kennebec) with an oryzacystatin I (OCI) cDNA clone linked to a CaMV 35S promoter. The transgenic plants accumulated active OCI in potato leaves, as demonstrated by the papain-inhibitory activity of transgenic plant leaf extracts. In addition to their anti-papain activity, the extracts also caused a partial but significant inhibition of CPB digestive proteinases, similar to that observed with pure inhibitors. Recombinant OCI did not alter the activity of the major potato leaf endogenous proteinases, which seemed to be of the serine-type. Therefore we suggest that the OCI cDNA can be used for the production of CPB-resistant transgenic potato plants without interfering with endogenous proteinases of these plants.Abbreviations CPB Colorado potato beetle - E-64 trans-epoxy-succinyl-L-leucylamido (4-guanidino) butane - OCI oryzacystatin I - PI proteinase inhibitor - PMSF phenylmethylsulfonyl fluoride     

马铃薯生育期进程的动态模拟研究

本研究系统解析和改进了前人关于作物生长温度效应的非线性模型,并对修改后的模型进行了解释,结合4年的田间试验数据和本研究提出的基于高斯方程的作物生长温度效应模型,建立了不同生态条件下马铃薯生育期进程的模拟模型．模型解析了地膜覆盖条件下土壤温度增加对马铃薯生育期进程的数值贡献,模拟了不同生态条件下马铃薯的生育期进展,结果表明模拟值与实测值具有良好的一致性。     

刺五加提取物对早期断奶仔猪生长性能和抗氧化能力的影响(英文)

为了研究刺五加提取物(ASE)替代抗生素降低仔猪早期断奶应激的效果及其作用机制.刺五加提取物多糖、黄酮和有机酸含量分别为2.94,0.19和1.04%;试验选用96头体重相近的21日龄杜×长×大断奶仔猪,按体重和性别随机分为3个处理,每个处理4个重复,分别饲喂基础日粮、添加ASE日粮(1 g/kg)和添加抗生素日粮(0.04%杆菌肽锌+0.03%咔吧氧).试验期为14 d,观察仔猪生长性能,测定7和14 d血清抗氧化指标等的变化.与基础日粮组相比,ASE和抗生素分别提高了仔猪日增重(ADG)16.81(P＞0.05)和24.66%(P＜0.05),均显著降低了料肉比(F/G)(P＜0.05);与抗生素组差异不显著.ASE和抗生素均可提高血清SOD水平;但是,在抗生素组中,第14 d仔猪血清SOD有降低的趋势(从147.96±15.88 U/mL降低至125.68±14.26U/mL).ASE有提高断奶后第7和14 d血清GSH含量的趋势(P=0.235和0.211),并极显著降低了7和14 d血清MDA水平(P＜0.05).结果表明,ASE可促进仔猪生长,提高机体抗氧化能力,在一定程度上可以替代抗生素.     

Plant extract contact toxicities to various developmental stages of Colorado potato beetles (Coleoptera: Chrysomelidae)

The contact toxicities of methanol extracts from the nine plant species Hedera helix, Artemisia vulgaris, Xanthium strumarium, Humulus lupulus, Sambucus nigra, Chenopodium album, Salvia officinalis, Lolium temulentum and Verbascum songaricum were tested on the developmental stages of Colorado potato beetle (CPB) (Leptinotarsa decemlineata). About 2 mL of plant extract, 40% (w/w), was applied to the first instar to fourth instar larvae and adult beetles using a Potter spray tower. Most of the tested plant extracts caused relatively low mortality in all the beetle instars. Among the plant extracts, H. lupulus extract was the most toxic to all stages of the insect, except for the adult beetles. Larval mortality ranged from 40% in the fourth instars to 84% in the third instars. In a second series of experiments, dose–response bioassays using H. lupulus extract produced lethal concentration 50 (LC₅₀) values ranging from 10%, 12%, 17% to 46% (w/w) active ingredient (plant material) for instars 1–4, respectively. This increasing mortality trend, however, did not extend to the adult stage where even the maximum dose of 40% plant material did not provide sufficient mortality to allow estimation of a LC₅₀. These results demonstrated that the extract from H. lupulus has potential as an active ingredient in biological pesticides developed to manage larval instars of the CPB. The potential uses of this plant extract may be in conventional and organic pest management or as part of a mixture of plant extracts or conventional insecticides. Before extracts can be considered as biological control agents, their impact on natural enemies should be assessed.     

细胞提取物重编程研究进展

体细胞重编程是在特定的条件下使已分化的细胞转变成为另一种细胞.体细胞重编程的方式主要有体细胞核移植技术、细胞融合技术、细胞提取物处理技术及特定转录因子转染技术.现有研究表明,细胞提取物重编程技术在体细胞重编程中发挥着一定的作用,为此,就该技术的最新研究进展和可能机制作一综述.     

表达PVY和PLRV双价外壳蛋白基因马铃薯的抗病性研究

表达马铃薯Y病毒(PVY)和马铃薯卷叶病毒(PLRV)双价外壳蛋白基因的马铃薯(Solanum tubero-sum L.)栽培品种“Favorita”和“虎头”,经摩擦接种PVY和用桃蚜接种PLRV后,观察症状并用ELISA测定病毒滴度。结果表明,两个品种转双价CP基因的各株系,接种病毒后表现无症状或症状轻微,其中PVY和PLRV平均滴度均较不转基因对照植株低。不同品种对PVY和PLRV的抗性比较表明,转双价CP基因的“Favorita”对PVY抗性较明显,而转双价CP基因的“虎头”则对PLRV抗性较对PVY抗性明显。不同转基因株系抗病毒水平不同。“Favorita”9个转双价CP基因株系中有6个株系PVY滴度较未转基因对照降低52.5％～90.0％,而“虎头”7个转双价CP基因株系中有4个株系PLRV含量较对照降低53.0％～98.0％。在抗性株系中还出现一些抗1种病毒或抗2种病毒的抗性较强的单株。     

45味中药乙醇提取物中对酪氨酸酶的激活作用

从中医治疗白癜风方剂中筛选出中药45味,观察这些中药50%乙醇提取物对蘑菇酪氨酸酶和无细胞系统多巴色素自动氧化生成黑素量的影响.结果显示有21味中药乙醇提取物在3个不同浓度对蘑菇酪氨酸酶活性、黑素生成具有激活作用,其中女贞子、梅花和八角茴香对酪氨酸酶的激活作用较明显;同时分析了其中有激活作用的中药的功用等分类情况,以探...     

毛竹各器官和根际土浸提液对杉木种子萌发的化感作用

随着毛竹杉木混交林面积的不断扩大,它们之间既会产生促进作用,又会产生抑制作用。本研究对比分析了不同浓度毛竹各器官(鲜叶、干叶、枝条、竹杆、竹鞭和鞭根)的浸提液及枯落物、根际土浸提液对杉木种子发芽率的影响,探讨了毛竹各器官浸提液及枯落物、根际土浸提液对杉木种子萌发的化感作用。结果表明:(1)处理前期,毛竹各器官浸提液对杉木种子萌发具有抑制作用,且当浸提液浓度为1∶25和1∶50的高浓度时,相对于低浓度浸提液对杉木种子萌发的抑制作用更为持久;(2)处理后期,低浓度的毛竹各器官浸提液对杉木种子萌发促进作用较快,而高浓度的浸提液仍呈现抑制作用,促进作用出现较为缓慢;(3)枯落叶浸提液总体上对杉木种子萌发具有抑制作用,在整个实验过程中低于对照组的发芽率,仅在1∶50浓度时略高对照组实验;而根际土浸提液对杉木种子萌发自始至终都具有促进作用,其中低浓度的促进作用十分显著。故在实际的毛竹杉木混交林生产营林过程中可选用毛竹根际土制备浸提液,促进杉木种子萌发,为毛竹杉木混交林的生产经营提供参考。     

四齿四棱草水提取物的化学成分研究

从四齿四棱草地上部分水煮提取物中分离得到11个化合物,通过波谱分析并与文献和标准品对照将它们分别鉴定为β-谷甾醇(1)、4-乙酰胺基乙基苯基6-O-甲基香豆酰吡喃葡萄糖基(1→2)[-βD-吡喃葡萄糖基(1→3)]-α-L-吡喃鼠李糖苷(2)、4-乙酰胺基乙基苯基6-O-甲基香豆酰吡喃葡萄糖基(1→2)[-βD-吡喃葡萄糖基(1→3)]-4-O-乙酰基-α-L-吡喃鼠李糖苷(3)、6-C--βL-吡喃阿拉伯糖基-8-C--αL-吡喃阿拉伯糖基洋芹素(4)、6,8-二-C-α-L-吡喃阿拉伯糖基洋芹素(5)a、cetylmartynoside B(6)i、somartynoside(7)a、lyssonoside(8)l、eucosceptoside B(9)、连翘苷B(10)和丁二酸(11)。其中2和3为顺反异构体的混合物。     

银杏叶提取物分子聚集形态

研究银杏叶提取物水溶液中多组分分子间的相互作用;采用动态光散射法和透射电镜扫描法,探讨银杏叶提取物水溶液是否存在分子聚集形态、分子聚集体粒径大小以及体外模拟不同胃肠pH环境条件下,银杏叶提取物水溶液分子聚集体的稳定性.实验数据证实银杏叶提取物水溶液存在纳米级分子聚集体,分子聚集体粒径在60 nm至100 nm之间;水溶液中1 nm以下的粒子大都是一些成分以单分子形式存在;随着溶液的浓度增加,分子聚集体的粒径也增大;在不同pH条件胃肠环境下,银杏叶提取物水溶液分子聚集体可以稳定存在.