Cell-wall lysing enzymes and products of cell-wall digestion elicit ethylene in citrus

Ethylene production was induced in Valencia oranges [ Citrus sinensis (L.) Osbcck] by injection of the fungal enzyme mixture Pectolyase ( Aspergillus japonicus ) which contains pectolytic enzymes into the peel. The mixture also stimulated production of 1-aminocyclopropane-1-carboxylic acid (ACC). Cycloheximide partially inhibited the Pectolyase-induced ethylene response. Pectin fragments, resulting from partial acid hydrolysis or Pectolyase digestion, caused an increase in ethylene production when injected into the peel of intact orange fruits. Pectic fragments produced by fungal enzymes are known to be elicitors of phytoalexins and in this study are shown to elicit ethylene in citurs.     

中华绒螯蟹卵巢RACE Cdna文库的构建

应用抑制性差减杂交技术 ,已经获得了中华绒螯蟹卵巢发育过程中差异表达基因的部分cDNA序列。为了进一步获得基因的全长cDNA序列 ,运用SMART技术 ,成功构建了中华绒螯蟹卵巢 (Ⅲ期 )RACEcDNA文库。琼脂糖凝胶电泳结果表明 ,文库所含全长cDNA的长度主要集中在 5 0 0～ 2 0 0 0bp之间 ,RACEPCR结果表明 ,所用基因特异性引物与接头引物皆能扩增出产物 ,说明所构文库的质量较好 ,适于用RACE方法从中分离中华绒螯蟹卵巢发育相关基因的全长cDNA。     

肥牛木根化学成分研究

从肥牛木(Cephalomappa sinensis)根的乙醇提取物中分离得到了7个化合物,经波谱分析确定其结构分别为:羽扇豆-20(29)-烯-2α,3β-二醇(1),苏门树脂醇酸(2),油桐酸(3),3-βstigmast-5-en-3-O--βD-xylopyranoside(4),东莨菪内酯(5),香草酸(6),油酸(7)。以上化合物均为首次从该植物中分离得到。     

自然干燥对冬虫夏草寄主蝠蛾卵孵化的影响

研究在室内自然空气湿度下放置的时间长短对冬虫夏草(Cordyceps)寄主昆虫贡嘎蝠蛾Hepialus gonggaensis Fu et Huang卵孵化率的影响。卵早期的研究结果为:第1批、第2批和第3批卵于室内自然空气湿度下保存的时间达26,11和16h后再保湿都可以正常孵化并且孵化率与对照无显著性差异,所孵化幼虫在饲养初期的成活率分别达62.0%,41.4%和43.4%,与对照无显著性差异。卵中期干燥放置36h的孵化率为66.7%,所孵化幼虫在饲养初期的成活率为50.0%,孵化率和成活率都与对照无显著性差异。卵晚期干燥放置24h的孵化率为70.0%,所孵化幼虫在饲养初期的成活率为49.0%,孵化率和成活率都与对照无显著性差异。以上结果表明,经历一定时间的干燥不会对卵的正常孵化有影响。     

地鳖虫后若虫期蛋白质和能量的需要量

为了探索地鳖虫后若虫期对蛋白质、能量等营养物质的需要量 ,通过双因子交叉分组试验 ,比较了不同能量、蛋白质水平的配合日粮对地鳖虫后若虫期生长速度和饲料转化率的影响。结果为 :在蛋白质水平组中 ,1、2、3、4、5水平组粗蛋白质含量分别为 1 9 1 3 %、1 8 0 9%、1 7 0 7%、1 6 1 0 %、1 5 1 3 % ,日增重与其它水平组差异显著 (P <0 0 5 )或极显著 (P <0 0 1 ) ;在能量水平组中 ,A、B、C水平组消化能为 1 3 2 7、1 2 2 6、1 1 2 8mJ kg ,日增重与其它水平组差异显著 (P <0 0 5 )或极显著 (P <0 0 1 )。结合各处理间饲料转化率的差异情况 ,筛选出地鳖虫后若虫期蛋白质和能量适宜需要量为 :粗蛋白 1 5 1 3 %～ 1 6 1 0 % ,消化能 1 1 2 8mJ kg。     

以松毛虫为基质培养的冬虫夏草菌丝体中多糖的提取研究

研究了不同方法对冬虫夏草发酵菌丝体（以枯叶蛾科昆虫马尾松毛虫为基质发酵所得）中多糖提取的影响。结果表明,采用微波辅助水提法所得多糖的产率最高,影响提取的关键因素为液料比、微波提取时间、微波功率;采用Box-Behnken设计及响应面分析法对这3个因素进行优化,并通过回归拟合,建立了预测虫草多糖提取的多项式模型Y=6.87+0.058A+0.085B+0.075C+0.032AB+0.046AC+0.069BC-0.16A²-0.37B²-0.11C²。经响应面最优化分析,获得冬虫夏草发酵菌丝体中多糖的最优提取工艺参数为：液料比（mL/g）6.3:1、微波功率520W、微波提取时间326s,此工艺提取验证后的提取率达到6.76%。     

Genome-wide analysis of the Chinese sturgeon sox gene family: identification,characterisation and expression profiles of different tissues

The sox family is assumed to be responsible for a number of developmental systems. Genome sequencing technology makes it possible to scan sox genes and conduct characteristic analyses of different species. In fish, full characterisation of sox genes at the genome-wide level has been reported for pufferfish Takifugu rubripes, medaka Oryzias latipes, tilapia Oreochromis niloticus and channel catfish Ictalurus punctatus. However, no systematic investigation of the sox family in sturgeons (Acipenseridae) has been reported to date. This study conducted genome-wide identification of the sox genes in the Chinese sturgeon Acipenser sinensis and profiled their tissue distribution between male and female individuals. In total, 19 sox genes were identified, including soxb1, b2, c, d, e, f and h, in the Chinese sturgeon. Genomic structure analysis indicated relatively conserved exon–intron structures in each sox group and phylogenetic analysis supported the previous classification of the sox family. Most of the sox genes showed a tissue-specific expression pattern, indicating the possible involvement of Chinese sturgeon sox genes at different developmental processes such as cardiac and gonadal development. This study provides a comprehensive resource of Chinese sturgeon sox genes and enables a better understanding of the evolution and function of the sox family.     

High Endemicity with Clonorchis sinensis Metacercariae in Fish from Yongjeon-cheon (Stream) in Cheongsong-gun,Gyeongsangbuk-do,Korea

The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yongjeon-cheon (a branch of Nakdong-gang) located in Cheongsong-gun, Gyeongsangbuk-do, the Republic of Korea (Korea). A total of 750 fishes in 19 species were examined by the artificial digestion method for 2 years (2019 and 2020). CsMc were detected in 378 (51.4%) out of 735 fishes in 14 species (73.7%), and the infection intensity was 666 per fish infected. In 2019, CsMc were found in 172 (68.0%) out of 253 fishes in 10 species, and the infection intensity was 565 per fish infected. In 2020, CsMc were detected in 206 (62.2%) out of 331 fishes in 10 species, and the infection intensity was 751 per fish infected. The other zoonotic trematode, ie. Metagonimus spp., Centrocestus armatus, Echinostoma spp. and Clinostomum complanatum, metacercariae were also detected in fishes from the survey streams, but their endemicities were relatively low. Conclusively, it was first confirmed that CsMc are highly endemic in fishes from Yongjeon-cheon in Cheongsong-gun, Gyeongsangbuk-do, Korea.     

白木香内生真菌的分离鉴定及其抑菌活性

从白木香Aquilaria sinensis（Lour．）Gilg木质部的树脂形成部位和健康部位中共分离获得42株内生真菌,经初步鉴定,产孢的33株分属于3目4科7属,其余未产孢的9株暂归为无孢菌群。采用杯碟法和MTT法分别测定了各菌株的发酵上清液对3种病原菌的体外抑菌活性和2种肿瘤细胞的体外细胞毒活性。结果表明,白木香木质部健康部位内生真菌以枝顶孢霉属为优势属,而树脂形成部位的内生真菌种类比健康部位要多,且以青霉属为优势属。其中26株至少能抑制一种指示菌,占总数的61．9％;7株对指示瘤株具有细胞毒活性,占总数的16．7％。抑菌活性菌株主要分布在枝顶孢霉属和青霉属。枝顶孢霉属菌株抑菌活性较强,其抗菌活性成分值得进一步研究。     

Effects of ammonium feeding on the production of bioactive metabolites (cordycepin and exopolysaccharides) in mycelial culture of a Cordyceps sinensis fungus

AIMS: To examine the effects of ammonium feeding on the production of cordycepin (3'-deoxyadenosine, a nucleoside analogue) and exopolysaccharides (EPS) in mycelial culture of a new Cordyceps sinensis fungus Cs-HK1. METHODS AND RESULTS: Cs-HK1 fungus was cultivated in a liquid medium containing glucose, yeast extract, peptone and a few major inorganic salts. NH(4)Cl was fed to the mycelial culture at various concentrations from 5 to 40 mmol l(-1) on day 3 (during exponential phase). NH(4)Cl, fed at 10 mmol l(-1), stimulated the cordycepin production most significantly, with nearly fourfold increase in the cordycepin content of mycelia (from 28.5 to 117 microg g(-1)), and also increased the EPS production by 40% (from 2.6 to 3.7 g l(-1)). The ammonium feeding had a slightly positive effect at 5-10 mmol l(-1), but a negative effect at higher concentrations on the mycelium growth. Ammonium feeding also caused a sharp drop of the medium pH, owing perhaps to the uptake of NH(3) and the release of H(+) by the fungal cells. CONCLUSIONS: Ammonium feeding to the mycelial culture of Cs-HK1 fungus enhanced the intracellular cordycepin accumulation and the EPS production. The enhanced cordycepin production may be attributed to the uptake of ammonia for nucleoside synthesis, and the enhanced EPS to the increased uptake of glucose for EPS biosynthesis. SIGNIFICANCE AND IMPACT OF THE STUDY: It is useful for the production of bioactive metabolites and for understanding ammonium metabolism and its relationship to the biosynthesis of nucleosides in a precious medicinal fungus.