The Aspergillus niger carbon catabolite repressor encoding gene, creA

In order to undertake a comparative analysis of carbon catabolite repression in two Aspergillus species, the creA gene has been isolated from A. niger by cross hybridization, using the cloned A. nidulans gene. The A. niger gene has been shown to be functional in A. nidulans by heterologous complementation of the creA204 mutation of A. nidulans. Overall, the genes show 90% sequence similarity (82% identity) at the amino acid (aa) level. There were some striking similarities between the aa sequences encoded by the two fungal creA genes and two genes involved in carbon catabolite repression in Saccharomyces cerevisiae. The zinc-finger regions showed 96% similarity (84% identity) with the zinc-finger region of the MIG1 gene of S. cerevisiae. The CREA protein contains a stretch of 42 aa that is identical in A. niger and A. nidulans, and these show 81% similarity (33% identity) with a region of the S. cerevisiae RGR1 gene.     

紫花苜蓿和斜茎黄耆水力提升作用及其对伴生植物的效应

为探讨紫花苜蓿(Medicago sativa)及斜茎黄耆(沙打旺, Astragalus laxmannii)与禾本科牧草混播后的水力提升现象, 揭示深、浅根性牧草的种间关系, 为混播草地的建植提供理论依据, 该研究开展了室外“上下盆”分根盆栽试验、采用土壤水分测定及“重水” (D₂O, 氘(D)含量>99.9%)标记法估算了苜蓿及斜茎黄耆分别与‘冬牧70’黑麦(Secale cereal ‘Dongmu 70’)不同混播比例(豆科:禾本科分别为3:7、5:5、7:3)条件下水力提升的发生情况及其对伴生牧草生长生理性状的影响。结果表明: ‘冬牧70’黑麦与斜茎黄耆混播后的产量显著高于其与紫花苜蓿混播后的产量, 同一种禾豆牧草混播组合不同混播比例中, 以AC2 (紫花苜蓿:‘冬牧70’黑麦为5:5)和BC3 (斜茎黄耆:‘冬牧70’黑麦为7:3)混播组合的总产量最高。不同单混播组合的单株整个生育期内日均提水量存在显著差异, 两种豆科牧草在混播时日均提水量均高于单播时, 斜茎黄耆单混播时的日均提水量显著高于紫花苜蓿, BC2组合(斜茎黄耆:‘冬牧70’黑麦为5:5)的日均提水量高于其他混播组合。在用标记水处理下盆土壤后, 各组合上下盆土壤水氢稳定同位素比率(δD)值显著升高。不同禾豆牧草组合上盆土壤水δD及禾本科牧草茎秆水δD、整株碳同位素分辨率(Δ¹³C)和产量数据表明, 在斜茎黄耆与‘冬牧70’黑麦混播比例为3:7、紫花苜蓿与‘冬牧70’黑麦混播比例为5:5时, 禾本科牧草水分状况或产量好于其他混播比例。以上结果表明, 两种深浅根豆科牧草与浅根性禾本科牧草混播种植时发生了水力提升现象, 两种豆科牧草提升的水分可以被伴生的禾本科牧草所吸收利用。     

Hydraulic lift of Medicago sativa and Astragalus laxmannii and its effect on their neighborhood plants

为探讨紫花苜蓿(Medicago sativa)及斜茎黄耆(沙打旺, Astragalus laxmannii)与禾本科牧草混播后的水力提升现象, 揭示深、浅根性牧草的种间关系, 为混播草地的建植提供理论依据, 该研究开展了室外“上下盆”分根盆栽试验、采用土壤水分测定及“重水” (D₂O, 氘(D)含量>99.9%)标记法估算了苜蓿及斜茎黄耆分别与‘冬牧70’黑麦(Secale cereal ‘Dongmu 70’)不同混播比例(豆科:禾本科分别为3:7、5:5、7:3)条件下水力提升的发生情况及其对伴生牧草生长生理性状的影响。结果表明: ‘冬牧70’黑麦与斜茎黄耆混播后的产量显著高于其与紫花苜蓿混播后的产量, 同一种禾豆牧草混播组合不同混播比例中, 以AC2 (紫花苜蓿:‘冬牧70’黑麦为5:5)和BC3 (斜茎黄耆:‘冬牧70’黑麦为7:3)混播组合的总产量最高。不同单混播组合的单株整个生育期内日均提水量存在显著差异, 两种豆科牧草在混播时日均提水量均高于单播时, 斜茎黄耆单混播时的日均提水量显著高于紫花苜蓿, BC2组合(斜茎黄耆:‘冬牧70’黑麦为5:5)的日均提水量高于其他混播组合。在用标记水处理下盆土壤后, 各组合上下盆土壤水氢稳定同位素比率(δD)值显著升高。不同禾豆牧草组合上盆土壤水δD及禾本科牧草茎秆水δD、整株碳同位素分辨率(Δ¹³C)和产量数据表明, 在斜茎黄耆与‘冬牧70’黑麦混播比例为3:7、紫花苜蓿与‘冬牧70’黑麦混播比例为5:5时, 禾本科牧草水分状况或产量好于其他混播比例。以上结果表明, 两种深浅根豆科牧草与浅根性禾本科牧草混播种植时发生了水力提升现象, 两种豆科牧草提升的水分可以被伴生的禾本科牧草所吸收利用。     

氮素和植物生长促进剂对羊草生长及竞争力的影响

选取羊草、斜茎黄芪、克氏针茅3种内蒙古典型草原常见植物,通过不同植物物种组合(单独种植或者羊草与其他两种混合种植)、施加不同剂量的氮素(0、0.1、0.2、0.4、0.8mg·g^-1)和植物生长促进剂——油菜素内酯(0.005 mg·g^-1)的温室盆栽试验,分析氮素和油菜素内酯对羊草生长及其与其他植物竞争力关系的影响.结果表明:添加氮素对羊草、斜茎黄芪的生物量影响显著,对克氏针茅的生物量影响较弱,并且氮素的影响因其伴生植物的不同而改变.氮素添加显著增加了羊草在单独种植和与斜茎黄芪混合种植时的地上生物量,但显著降低了与克氏针茅混合种植时的地下生物量.由于土壤可利用氮增加,羊草的地上与地下分配发生变化,表现为单独种植、与克氏针茅混合种植时,根冠比下降;与斜茎黄芪混合种植时,氮素添加对羊草根冠比的影响则不显著.油菜素内酯对植物生长的显著影响不普遍,仅显著降低了斜茎黄芪单独种植时的地下生物量;在羊草与斜茎黄芪混合种植时,显著增加了羊草地上生物量.油菜素内酯和氮适量联用可有效增加特定物种组合的生物量,从而在退化草地恢复中具有一定的应用前景.     

4种蚜虫对异色瓢虫生长发育和繁殖的影响

为明确桃蚜、萝卜蚜、胡萝卜微管蚜、瓜蚜对异色瓢虫种群扩繁的适宜性,在实验室条件下,以4种蚜为食料构建异色瓢虫两性生命表,研究不同蚜虫对异色瓢虫生长发育和繁殖的影响。结果表明: 取食不同蚜虫,异色瓢虫未成熟期由长到短依次为萝卜蚜(18.18 d)、瓜蚜(17.48 d)、胡萝卜微管蚜(16.23 d)、桃蚜(15.77 d);成虫前期存活率由高到低依次为胡萝卜微管蚜(88.3%)、桃蚜(86.7%)、萝卜蚜(55.0%)、瓜蚜(55.0%);成虫繁殖力由高到低依次为胡萝卜微管蚜(1750.5粒)、桃蚜(1441.5粒)、瓜蚜(1006.3粒)、萝卜蚜(965.2粒);成虫寿命由长到短依次为胡萝卜微管蚜(78.8 d)、桃蚜(63.1 d)、瓜蚜(54.3 d)、萝卜蚜(48.4 d);异色瓢虫种群内禀增长率r_m由高到低依次为桃蚜(0.19)、胡萝卜微管蚜(0.18)、萝卜蚜(0.14)、棉蚜(0.14);净增值率R₀由高到低依次为胡萝卜微管蚜(895.83)、桃蚜(600.62)、萝卜蚜(273.47)、棉蚜(268.33)。4种蚜虫中,胡萝卜微管蚜和桃蚜更有利于异色瓢虫种群扩繁。     

不同降水条件下内蒙古荒漠草原主要植物物候对长期增温和氮添加的响应

植物物候是生态系统对气候变化响应的重要指示器,是植物生产力与植被动态模拟的重要参数。但是植物物候对全球变化的响应是否存在年际间变异、年内变异、物种间变异或生境间变异,以及如何改变,目前仍然不明确。该研究基于内蒙古荒漠草原长期增温和氮添加实验平台,选择优势植物短花针茅(Stipa breviflora)、冷蒿(Artemisia frigida)和木地肤(Kochia prostrata)为研究对象,使用物候打分观测方法和Richards生长曲线拟合方法,研究了实验处理第11、12和13年(2016–2018年)期间增温和氮添加对植物物候的影响。研究结果表明:(1)短花针茅开花时间集中在第129–145天,冷蒿开花时间集中在第230–248天,木地肤开花时间集中在第194–222天。增温、氮添加和增温+氮添加均使短花针茅和木地肤开花时间趋于提前,冷蒿开花时间趋于推迟。(2)短花针茅结果时间集中在第134–148天,冷蒿结果时间集中在第241–260天,木地肤结果时间集中在第207–231天。增温、氮添加和增温+氮添加处理均使短花针茅和木地肤结果时间趋于提前,冷蒿结果时间趋于推迟。(3)短...     

放牧影响下典型草原克氏针茅和多根葱根系属性比较

植物根系属性与其生态适应性密切相关.为明确不同放牧干扰下克氏针茅和多根葱两种优势植物根系属性差异,比较了轻度放牧、中度放牧、重度放牧下克氏针茅和多根葱地下根系长度、根系表面积、根系直径、根系体积、根尖数、根系分叉数、比根长和比表面积的形态特征,分析了2种植物根尖比、根长比、表面积比、体积比等根系形态格局,研究两种植物对...     

Deracemization of aryl ethanols and reduction of acetophenones by whole fungal cells of Aspergillus terreus CCT 4083, A. terreus CCT 3320 and Rhizopus oryzae CCT 4964

The enantioselective deracemization of a number of p-substituted aryl ethanols and the reduction of p-substituted acetophenones were carried out with whole fungal cells of Aspergillus terreus CCT 4083, A. terreus CCT 3320 and Rhizopus oryzae CCT 4964 giving the corresponding alcohols in enantiomeric excesses up to >99%.     

白音华矿区草地群落主要物种组成及空间分布

以内蒙古白音华矿区周边草地为对象,研究了矿区草地植物群落的主要物种组成及其空间分布特征。结果表明: 草地群落共出现55种植物,优势种为大针茅、黄囊苔草和糙隐子草,常见种有羊草、冰草和知母等,该6个物种的累计相对重要值为79.6%,其密度分别为 26.6、204.7、105.4、107.1、68.2和55.1株·m^-2。对6个主要物种的种群密度通过半方差函数进行模型拟合, 其种群分布分别符合指数模型、指数模型、指数模型、球状模型、线性模型和高斯模型;对其空间分布格局进行分析,各种群的结构比分别为59.2%、97.2%、89.1%、94.5%、62.6%和72.1%,表明黄囊苔草、糙隐子草和羊草种群的空间自相关性程度均较高, 主要受结构性因素影响, 而大针茅、冰草和知母种群主要受随机性因素影响。对分形维数进行分析发现, 大针茅、黄囊苔草、糙隐子草和冰草种群分布格局较简单,空间依赖性较强,而羊草和知母种群分布格局较复杂,空间依赖性较弱,结合2D及3D图看, 大针茅和知母呈现出梯度扩散,而黄囊苔草、糙隐子草、羊草和冰草则主要呈现斑块化分布,表明矿区草地群落主要物种的空间分布与开矿无显著关联性。     

黄土丘陵区草本植物叶片与枯落物生态化学计量学特征

以黄土高原延河流域森林、森林草原和草原3个植被区的4种典型草本植物达乌里胡枝子、长芒草、铁杆蒿、茭蒿的叶片和枯落物为对象,测定叶片和枯落物中碳(C)、氮(N)、磷(P)、钾(K)含量及其比值,分析草本植物在该区域的养分限制及再吸收规律.结果表明: 4种植物叶片N/P均小于14,生长主要受氮元素含量限制;除达乌里胡枝子外,其他3种植物N、P、K的养分再吸收效率平均值分别为48.7%、32.5%、79.9%.茭蒿和铁杆蒿较高的N、P、K养分再吸收效率和叶片K含量有助于其在水分竞争中占据优势.铁杆蒿枯落物的C/N显著低于长芒草和茭蒿的枯落物,因而更易分解和进行养分循环.这可能是铁杆蒿在3个植被区分布广泛的原因之一.     

Oligosaccharide and alkyl β-galactopyranoside synthesis from lactose with Caldocellum saccharolyticum β-glycosidase

The synthetic utility of the thermostable β-glycosidase from Caldocellum saccharolyticum was investigated. The ability of the enzyme to catalyze oligosaccharide and β-galactopyranoside synthesis from lactose was compared with that of the readily commercially available, moderately thermostable β-galactosidase (β- -galactoside galactohydrolase, EC 3.2.1.23) from Aspergillus oryzae. Generally, the C. saccharolyticum enzyme showed significantly greater resistance to inactivation by heat and organic solvent and better yields of product. Although the A. oryzae enzyme gave better oligosaccharide yields at lower lactose concentrations, at higher concentrations (above 50% w/w) the C. saccharolyticum enzyme was significantly better, yielding a sugar mixture containing 42% by weight of tri- plus tetra-saccharides, from a 70% w/w lactose solution, compared with 31% by weight of oligosaccharides with the A. oryzae enzyme. In ethyl galactoside synthesis from ethanol and lactose, neither enzyme appeared to hydrolyze the product to any great extent. Under all conditions tested, the product yield did not peak, even at long reaction times, when most of the lactose had been consumed. The C. saccharolyticum enzyme, however, gave slightly higher product yields and could be used at higher ethanol concentrations without serious loss of activity.     

普通菜豆抗菜豆象性状的全基因组关联分析

普通菜豆(Phaseolus vulgaris)具有丰富的营养价值, 菜豆象(Acanthoscelides obtectus)是危害菜豆的主要害虫, 利用抗虫种质资源防治菜豆象是最安全且经济有效的方法。该研究利用改良的室内人工接虫方法, 对625份普通菜豆种质资源进行2次菜豆象抗性重复鉴定, 筛选出2份抗性稳定且种子受害率均在10%以下的高抗种质。利用种子受害率和蛀孔总数的表型数据, 基于3 767 432个SNP标记进行全基因组关联分析, 鉴定出15个与种子受害率相关的显著关联遗传位点, 8个与蛀孔总数相关的显著关联位点, 解释了4.54%-5.56%的表型变异。在候选位点筛选出包括编码蛋白酶抑制剂、凝集素和过氧化物酶等在内的20个与抗虫防御相关的候选基因。     

外来入侵植物黄花刺茄与其近缘非入侵植物少花龙葵繁育系统的比较

黄花刺茄是一种具有严重危害性的外来入侵植物,本研究以分布于我国的4个黄花刺茄种群为材料,与其同属的外来非入侵植物少花龙葵为近缘种对照,在同质种植园内对其繁育系统进行了比较研究。黄花刺茄和少花龙葵在开放性授粉和补充授粉条件下的平均结籽率没有显著差异;套袋处理下,黄花刺茄的平均结籽率(29.5%)显著低于少花龙葵(47.0%);去雄套袋处理下两者均没有可育种子产出,表明黄花刺茄和少花龙葵均无自发无融合生殖特性。黄花刺茄的平均自交指数为0.38,低于少花龙葵(0.64);平均花粉限制指数(0.29)和平均传粉者的贡献指数(0.49)均大于少花龙葵(0.08和0.31)。目前黄花刺茄分布于中国的12个省份,在全球发生数量为3835次;少花龙葵分布于中国的18个省份,在全球发生数量为10897次。外来入侵植物黄花刺茄的自交亲和性低于外来非入侵植物少花龙葵,说明自交亲和性高低与两种植物的入侵性强弱无显著相关关系,但与其分布范围呈正相关。     

刈割留茬高度对大针茅草原群落结构及稳定性的影响

2014—2018年8月在内蒙古锡林郭勒盟毛登牧场大针茅典型草原,以围封为对照,设置2、5和8 cm 3个刈割留茬高度,研究刈割留茬高度对群落结构及稳定性的影响。结果表明: 群落中共出现15科23属27种植物;优势种为大针茅、知母、羊草及糙隐子草,累计相对重要值为76.1%。多年生杂类草15种,一、二年生植物5种,多年生丛生禾草和灌木半灌木植物各有3种,多年生根茎禾草有1种。大针茅等处于群落上层;知母、羊草等植物处于群落中层;糙隐子草、刺穗藜、猪毛菜等植物处于群落底层。刈割造成大针茅及多年生丛生禾草相对重要值降低,使得糙隐子草、刺穗藜、猪毛菜及一、二年生植物相对重要值增加。留茬2 cm降低羊草相对重要值,而留茬5、8 cm使其增加;留茬5 cm增加知母相对重要值,而留茬2、8 cm使其降低;留茬8 cm降低杂类草相对重要值,而留茬2、5 cm使其增加。物种及功能群多样性年度间差异显著。总体上,刈割对物种丰富度无显著影响,对其物种多样性影响较小,但对功能群多样性存在一定影响。表明在刈割过程中,群落各功能群存在一定的补偿作用,使得群落保持相对稳定。刈割使群落稳定性增加,留茬5和8 cm时群落稳定性较大;留茬5 cm时群落变异性较大,而留茬8 cm时最小。留茬8 cm时群落稳定性高且变异性小,能促进群落长期稳定。     

Structural features of the glycogen branching enzyme encoding genes from aspergilli

A maltose binding protein, p78, was purified to homogeneity from Aspergillus nidulans by a single column chromatography step on cross-linked amylose. The partial amino acid sequence was highly homologous to the glycogen branching enzymes (GBEs) of human and yeast, and p78 did show branching enzyme activity. The genomic gene and its cDNA encoding GBE (p78) were isolated from the A. nidulans genomic and cDNA libraries. Furthermore, a cDNA encoding A. oryzae GBE was entirely sequenced. A. nidulans GBE shared overall and significant amino acid sequence identity with GBEs from A. oryzae (83.9%), Saccharomyces cerevisiae (61.1%) and human (63.0%), and with starch branching enzymes from green plants (55–56%).     

Biopreparation of cotton fabric with enzymes produced by solid-state fermentation

Fungal enzyme preparations from Phanerochaete chrysosporium, Aspergillus oryzae, Aspergillus giganteus and Trichoderma virens, produced by solid-state fermentation (SSF) on cotton seed-coat fragment waste as substrate and enzyme inducer were investigated in biopreparation of cotton fabric. Cotton seed-coat fragment is rich in lignin, cellulose and hemicelluloses, therefore enzyme complexes produced by target fungi on such a substrate can be used effectively to degrade impurities in cotton fabrics during biopreparation. Activities of extracellular hydrolytic and ligninolytic enzymes were determined from the SSF extract materials. The potential of the hydrolytic and accompanying oxidative enzymes in the whole SSF cultures was exploited in degradation of seed-coat fragments and other coloring materials of greige cotton fabric. Enzyme assays indicated that many extracellular enzymes have been produced under these conditions including both hydrolytic and oxidative enzymes. A. oryzae NRRL 3485 produced significantly higher amounts of both hydrolytic and oxidative enzymes than other tested fungi. Best results in removal of seed-coat fragments from cotton fabric were obtained by P. chrysosporium NCAIM (=ATCC 34541), P. chrysosporium VKM F-1767 and A. oryzae NRRL 3485 SSF enzyme complexes.     

稻镰状瓶霉对水稻白叶枯病的生物防治

本文研究了野生稻暗色有隔内生真菌稻镰状瓶霉与水稻的共生关系,通过根部接种DsRED荧光标记菌株,观察稻镰状瓶霉在水稻根系内的定殖,并对其抗白叶枯病特性进行调查,结果发现：经叶部接种白叶枯病菌后,对照组发病严重,病级集中在7级和9级,分别占比43.33%和34.67%,病情指数为79.26;相比之下,接种了稻镰状瓶霉的水稻植株发病较轻,叶片病斑面积小,并伴随零星黑色过敏性坏死斑出现,未发病植株占8%,72%的植株病级为1级,病情指数仅为15.26。稻镰状瓶霉对水稻白叶枯病的防治效果达到80.75%。稻镰状瓶霉的定殖能够引起叶片中超氧化物歧化酶、过氧化氢酶和过氧化物酶活性极显著提高,分别是对照组的5.26、12.08和10.53倍;诱导PR1a和PR1b显著上调表达8.71和3.37倍,AOS、OsSAUR2和EL5基因显著下调表达0.28、0.57和0.65倍。利用野生稻内生真菌防控水稻白叶枯病,在国内外尚属首次,可为水稻白叶枯病的生物防治提供新途径。     

入侵豚草与本地植物竞争对丛枝菌根真菌多样性的影响

外来植物入侵常引起入侵地丛枝菌根真菌（arbuscular mycorrhizal fungi,AMF）多样性的变化,但AMF多样性的变化与入侵域本地植物种类相关性目前尚不清楚。本研究采用野外同质园试验研究豚草与不同本地植物竞争时对AMF多样性的影响。本试验共设入侵豚草单种、本地植物狗尾草Setaria viridis单种、藜 Chenopodium album单种、黄香草木犀Melilotus officinalis单种、豚草和狗尾草混种、豚草和藜混种、豚草和黄香草木犀混种以及裸土（无任何植物生长）对照8个处理。采集根区土样后分离、鉴定AMF,分析植株生物量和AMF物种多样性变化间的关系。结果表明,对豚草而言,单种处理中生物量均高于混种处理;豚草分别与3种本地植物竞争时,与黄香草木犀混种中豚草竞争能力最强,而与藜混种中竞争能力最弱。豚草分别与3种本地植物混种时土壤中AMF种丰度和香农-威纳指数分别显著高于豚草单种和本地植物单种,其中豚草与藜混种中AMF的种丰度和香农-威纳指数最高,与狗尾草混种中AMF的种丰度和香农-威纳指数最低,而豚草分别与3种本地植物混种处理中孢子密度显著低于本地植物单种（豚草与黄香草木犀混种除外）。豚草单种、狗尾草单种、藜单种、豚草分别与狗尾草和藜混种4个处理中AMF优势种均为网状球囊霉Glomus reticulatum和缩隔球囊霉Septoglomus constrictum;黄香草木犀单种中优势种是网状球囊霉、缩隔球囊霉和根内根孢囊霉Rhizophagus Intraradices,豚草与黄香草木犀混种中优势种是网状球囊霉和根内根孢囊霉;狗尾草单种、豚草与狗尾草混种和豚草与藜混种3个处理的特有种分别是木薯根孢囊霉Rhizoglomus manihotis、近明球囊霉Claroideoglomus claroideum和美丽盾巨孢囊霉Scutellospora calospora。狗尾草单种生物量与孢子密度呈显著正相关,豚草与狗尾草混种中豚草的生物量与均匀度呈显著负相关,豚草与黄香草木犀混种中豚草的生物量与孢子密度呈显著正相关,与香农威纳指数呈显著负相关。综上可知,豚草与本地植物竞争对AMF多样性的影响具有异质性,这与本地植物种类密切相关。     

Growth inhibition of the cereal root pathogens Rhizoctonia solani AG8, R. oryzae and Gaeumannomyces graminis var. tritici by a recombinant 42-kDa endochitinase from Trichoderma harzianum

The objective of this study was to determine the effectiveness of a 42-kDa endochitinase coded by the ThEn42 gene from Trichoderma harzianum as a potential source of transgenic resistance to Rhizoctonia root rot of barley caused by Rhizoctonia solani AG8 and/or R. oryzae. The gene cThEn42 was codon optimized (GC content increased from 53.3 to 65.1%) and then synthesized to produce the modified cThEn42GC in Pichia pastoris for in vitro tests. Two expression vectors were constructed: one with the fungal signal peptide and the fungal activation peptide [FSP-FAP-cThEn(GC)] and the other with barley chitinase 26 signal peptide followed by the fungal signal and activation peptides [SP(HVChi26)-FSP-FAP-cThEn(GC)]. N-terminal sequencing showed that, of two proteins secreted into liquid medium, FSP was cleaved off faithfully in one protein and both FSP and FAP were cleaved from the other protein. Purified endochitinase provided strong in vitro inhibition of both R. solani AG8 and R. oryzae. The enzyme had an intermediate inhibitory activity against Gaeumannomyces graminis var. tritici, and no inhibitory activity against Fusarium graminearum, F. pseudograminearum, and F. culmorum.