Dau c 1.01 and Dau c 1.02-silenced transgenic carrot plants show reduced allergenicity to patients with carrot allergy

Pathogenesis-related protein-10 (PR10) is a ubiquitous small plant protein induced by microbial pathogens and abiotic stress that adversely contributes to the allergenic potency of many fruits and vegetables, including carrot. In this plant, two highly similar genes encoding PR10 isoforms have been isolated and designated as allergen Dau c 1.01 and Dau c 1.02. The aim of the study was to generate PR10-reduced hypoallergenic carrots by silencing either one of these genes in transgenic carrots by means of RNA interference (RNAi). The efficiency of gene silencing by stably expressed hairpin RNA (hnRNA) was documented by means of quantitative RT-PCR (qPCR) and immunoblotting. Quantification of the residual protein revealed that PR10 accumulation was strongly decreased compared with untransformed controls. Treatment of carrot plants with the PR protein-inducing chemical salicylic acid resulted in an increase of PR10 isoforms only in wild-type but not in Dau c 1-silenced mutants. The decrease of the allergenic potential in Dau c 1-silenced plants was sufficient to cause a reduced allergenic reactivity in patients with carrot allergy, as determined with skin prick tests (SPT). However, simultaneous silencing of multiple allergens will be required to design hypoallergenic carrots for the market. Our findings demonstrate the feasibility of creating low-allergenic food by using RNAi. This constitutes a reasonable approach to allergen avoidance.     

五节芒定居对尾矿砂重金属形态、微生物群落功能及多样性的影响

选择尾矿砂裸地和4个五节芒(Miscanthus floridulus)定居地(RI、RII、RIII和RIV)为样地, 分别研究了五节芒定居对尾矿砂重金属形态转化和微生物功能参数的影响。结果表明: 五节芒自然定居显著地提高了尾矿砂碳酸盐结合态和硫化物-有机物结合态重金属比例(p＜0.05), 降低了尾矿砂残渣态重金属的比例(p＜0.05)。土壤微生物群落的纤维素分解作用、酚转化作用、固氮作用、氨化作用、硝化作用、有机磷转化作用、功能多样性、4类不同碳源(碳水化合(CH)、聚合物(PL)、胺类化合物(AM)和杂合物(ML))均随着五节芒自然定居显著提高(p＜0.05)。而氨基酸(AA)的利用强度却显著下降(p＜0.05)。典范相关分析(CCA)表明: 土壤微生物功能参数的总体变化与土壤碳酸盐结合态和硫化物-有机物结合态重金属的含量呈显著正相关, 与残渣态重金属含量呈显著负相关。该研究结果表明, 五节芒定居不仅促进了尾矿砂重金属朝着沉淀态和螯合态方面转化, 而且还显著地改善了尾矿砂微生物群落的功能发挥。因而, 五节芒在重金属矿业废弃地恢复实践中具有较大的应用潜力。     

中国红豆杉细胞紫杉醇合成期与非紫杉醇合成期基因表达差异初步分析

紫杉醇 (Ｐａｃｌｉｔａｘｅｌ,商品名为Ｔａｘｏｌ)是存在于红豆杉属(Ｔａｘｕｓｓｐ .)植物中的一种四环二萜酰胺类化合物 ,因其具有广谱强效的抗癌活性和独特的抗癌机理而倍受人们关注。然而 ,紫杉醇天然资源十分有限 ,自 1992年美国食品与药物管理局 (ＦＤＡ)批准紫杉醇用于癌症的临床治疗以来 ,其供需矛盾日益尖锐[1 ] 。目前 ,普遍认为采用红豆杉细胞悬浮培养生产紫杉醇是解决其药源紧缺问题的最佳途径之一。迄今为止 ,在红豆杉细胞的代谢规律和培养方面均取得一定成果 ,但前景仍不容乐观 ,离工业化大规模生产还有相当大的距离 ,主要…     

Desensitization of Bacillus subtilis aspartokinase I to allosteric inhibition by meso-diaminopimelate allows aspartokinase I to function in amino acid biosynthesis during exponential growth.

Strains of Bacillus subtilis deficient in aspartokinases II and III are unable to grow in the absence of lysine, methionine, and threonine, although they have normal levels of aspartokinase I (J.J. Zhang, F.M. Hu, N.Y. Chen, and H. Paulus, J. Bacteriol. 172:701-708, 1990). Revertants with the ability to grow in the absence of lysine and methionine had an altered aspartokinase I, which was insensitive to feedback inhibition by meso-diaminopimelate. This suggests that inhibition by meso-diaminopimelate limits the ability of aspartokinase I to function in amino acid biosynthesis.     

海洋生态资本价值结构要素与评估指标体系

针对海洋生态系统的特点,构建了海洋生态资本价值的结构要素及其评估指标体系。海洋生态资本的价值是指海洋生态资本的存量价值及其产生的收益流价值,包括各类海洋生态资源的现存量价值及其组成海洋生态系统整体而产生的生态系统服务价值。其中,海洋生态资源的现存量价值由海洋生物资源存量价值和海洋生境资源存量价值构成。海洋生态系统服务价值包含海洋供给服务、海洋调节服务、海洋文化服务和海洋支持服务等4个子要素的价值。     

一类BAM随机神经网络的稳定性

对于一类双向联想记忆（BAM）随机神经网络。研究其全局稳定性和指数稳定性,利用Schwarz积分不等式和Ito积分性质,给出其稳定性判定的充分性条件．     

Identification of xylanase-producing fungi EIM-30 and its optimization of submerged fermentation conditions

通过对木聚糖酶高产菌株EIM-30基于形态学和18S rDNA序列的系统发育进化分析,鉴定为里氏木霉Trichoderma reesei.在单因子实验确定EIM-30产木聚糖酶的最适碳源和氮源的基础上,通过Plackett-Burman实验对影响其产酶的相关因素进行评估并筛选出3个显著效应因子,然后应用最陡爬坡实验和响应面分析确定最适产酶培养基配方为:酵母浸膏1.50％,蛋白胨1.00％,NaCl 0.50％,PPG-2000 0.10％,MgSO4 1.20％,CaCl2 0.18％,(NH4)2 SO4 0.45％,甘油4.18％,乳糖3.05％,K2HPO41.59％.优化后Trichoderma reesei EIM-30的液体发酵产木聚糖酶的活力可达9.857×105 U/mL,较优化前提高1.98倍.     

Effects of chronic hypogonadism on corticosterone secretion and cyclic AMP production in male rat adrenocortical cells

AIM: To determine the secretion of corticosterone (CCS) both in vivo and in vitro during different intervals after orchidectomy in male rats. METHODS: Three- and 12-month-old rats had been orchidectomized 0, 3, 6, or 9 months before decapitation. RESULTS: Orchidectomy increased the concentrations of plasma CCS, the basal release of CCS, and the adenosine 3', 5'-cyclic monophosphate (cAMP) production in rat zona fasciculata reticularis (ZFR) cells. The forskolin/3-isobutyl-l-methylxanthine-stimulated releases of CCS and cAMP production by ZFR cells were higher in rats with chronic hypogonadism. The CCS release from ZFR cells of orchidectomized rat was not altered by 8-bromo-cAMP treatment. Orchidectomy enhanced the stimulatory effect of deoxycorticosterone on CCS release in ZFR cells. CONCLUSION: These results suggest that orchidectomy-related increases of CCS secretion in rats are associated with an increase of adenylate cyclase activity, cAMP generation, and 11-beta-hydroxylase activity in ZFR cells.     

江西吉安灰头麦鸡的繁殖生态研究

灰头麦鸡Vanellus cinereus在江西吉安地区是夏候鸟.2010 ～2011年对当地灰头麦鸡的繁殖生态进行了调查研究.结果表明,当地灰头麦鸡最早2月20日迁入,最晚9月17日迁离,居留时间约为7个月;3月初开始产卵,平均窝卵数3.8枚(n=14),平均卵大小48.0 mm×34.5 mm,平均卵重28.8 g(n =38);产满窝卵后即开始孵卵,孵卵由雌雄鸟共同承担;孵卵期为28 ～31 d;孵化率为90.15％.