转YHem1 番茄植株耐盐性的研究

 YHem1是一个由拟南芥HemA1启动子（一种光响应型启动子）控制的酿酒酵母菌5–氨基乙酰丙酸（ALA）合酶基因（Hem1）。将该基因转化番茄植株,可以提高叶片内源ALA含量及其代谢能力,增加叶绿素含量和抗氧化酶活性,并降低产生速率和丙二醛（MDA）含量。200 mmol ·L^-1 NaCl处理,降低了野生型番茄叶片ALA合成与代谢能力和叶绿素含量,同时诱导叶片产生速率、H₂O₂和丙二醛（MDA）含量上升,而超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）和抗坏血酸过氧化物酶（APX）等抗氧化酶活性则逐渐降低。盐胁迫也导致转YHem1番茄ALA合成与代谢能力、叶绿素含量和抗氧化酶活性下降,但其降幅明显低于野生型。盐处理10 d后,转基因番茄植株保持着较高的生物学积累量和较低的盐胁迫抑制程度,说明转入YHem1基因可以提高番茄耐盐性。此外,转基因番茄叶片H₂O₂含量始终保持较高水平,暗示其可能作为一种信号分子参与细胞生理调节。     

Amino Acid-Coupled Bromophenols and a Sulfated Dimethylsulfonium Lanosol from the Red Alga Vertebrata lanosa

Vertebrata lanosa is a red alga that can commonly be found along the shores of Europe and North America. Its composition of bromophenols has been studied intensely. The aim of the current study was therefore to further investigate the phytochemistry of this alga, focusing more on the polar components. In total, 23 substances were isolated, including lanosol-4,7-disulfate (4) and the new compounds 3,5-dibromotyrosine (12), 3-bromo-5-sulfodihydroxyphenylalanine (13), 3-bromo-6-lanosyl dihydroxyphenylalanine (14), 3-(6′-lanosyl lanosyl) tyrosine (15) and 5-sulfovertebratol (16). In addition, 4-sulfo-7-dimethylsulfonium lanosol (7) was identified. While, in general, the dimethylsulfonium moiety is widespread in algae, its appearance in bromophenol is unique. Moreover, the major glycerogalactolipids, including the new ((5Z,8Z,11Z,14Z,17Z)-eicosapentaenoic acid 3′-[(6′’-O-α-galactopyranosyl-β-D-galactopyranosyl)]-1-glycerol ester (23), and mycosporine-like amino acids, porphyra-334 (17), aplysiapalythine A (18) and palythine (19), were identified.     

Production of Carotenoids and Phospholipids by Thraustochytrium sp. in Batch and Repeated-Batch Culture

The carotenogenic thraustochytrid Thraustochytrium sp. RT2316-16 was grown in batch and repeated-batch cultures using different feeds containing glucose, or glycerol, and yeast extract, for the production of lipids, phospholipids and carotenoids. RT2316-16 produced canthaxanthin, astaxanthin and β-carotene. The effects of biotin, ascorbic acid, light and temperature were evaluated in some of the experiments. In 2-day-old batch cultures, the combined mass percentage of eicosapentaenoic acid and docosahexaenoic acid in total lipids was between 16.5% (glycerol-based medium in the dark; biomass concentration = 4.2 ± 1.1 g L⁻¹) and 42.6% (glucose-based medium under light; biomass concentration = 3.3 ± 0.1 g L⁻¹), decreasing to 3.8% and 6.1%, respectively, after day 4. In repeated-batch cultures, the total lipids in the biomass increased after glucose or glycerol was fed alone, whereas the total carotenoids (168 ± 7 μg g⁻¹ dry weight (DW)) and phospholipids in the biomass increased after feeding with yeast extract. The biomass with the highest content of phospholipids (28.7 ± 4.3 mg g⁻¹ DW) was obtained using a feed medium formulated with glycerol, yeast extract and ascorbic acid. Glycerol was the best carbon source for the production of a biomass enriched with total lipids (467 ± 45 mg g⁻¹ DW). The composition of carotenoids depended strongly on the composition of the feed. Repeated-batch cultures fed with yeast extract contained canthaxanthin as the main carotenoid, whereas in the cultures fed only with glucose, the biomass contained mainly β-carotene.     

多杀菌素微球制备关键工艺研究:Ⅱ

采用乳化-溶剂挥发法,以聚乳酸(PLA)为成球材料(壁材)制备了多杀菌素微球。研究了PLA浓度和油/水相体积比对多杀菌素微球制备的影响规律,确定了制备多杀菌素微球的优选配方及工艺条件。制备得到中位径(D50)为12.73 μm、跨距为1.4811、载药量在31%左右、包封率为100.2%、包封产率为89.4%的多杀菌素微球,重复性良好。扫描电镜(SEM)观察结果表明,所得微球为表面较光滑的实心小圆球。差示扫描量热(DSC)分析结果证实,多杀菌素和PLA的确形成了载药微球。室内毒力测定结果表明,自制5%多杀菌素微球悬浮剂与市售2.5%多杀菌素悬浮 剂(菜喜)对小菜蛾Plutella xylostella 2龄幼虫的毒力基本相同,LC50值分别为0.40和0.38 μg/mL。     

黄腐酸对雾培马铃薯幼苗抗旱性的影响

试验以马铃薯(Solanum tuberosum)幼苗为研究对象,采用雾培装置进行不同黄腐酸用量和干旱胁迫处理(分别为CK,不加黄腐酸和PEG; 10％ PEG;0.01％ FA+ 10％ PEG;0.03％ FA+ 10％ PEG;0.05％ FA+ 10％ PEG和0.10％ FA+ 10％ PEG),分析其对马铃薯生长发育及抗性生理的影响。结果表明,在干旱胁迫下,雾培马铃薯幼苗的成活率、叶绿素含量、膜稳定指数、根系活力、匍匐茎数、结薯率和产量呈下降趋势,而丙二醛(MDA)、过氧化氢(H₂O₂)、脯氨酸、可溶性糖含量和过氧化氢酶(CAT)活性及超氧阴离子(O^-₂)产生速率呈上升趋势,过氧化物歧化酶(SOD)和过氧化物酶(POD)活性先增加后下降,说明雾培马铃薯幼苗在干旱胁迫下生长发育受到显著抑制,正在遭受逆境胁迫。经黄腐酸处理后,幼苗的成活率、匍匐茎数、结薯率和产量则得到了提高,而叶绿素含量、膜稳定指数和根系活力仍呈下降趋势,但较单一干旱胁迫的下降趋势缓慢,而MDA含量、SOD和POD活性及产生速率呈先升高后下降的趋势,脯氨酸、可溶性糖、H₂O₂含量及CAT活性呈上升趋势,其中H₂O₂含量上升趋势较单一干旱胁迫缓慢,说明黄腐酸处理后使干旱胁迫下雾培马铃薯幼苗的生长发育得到了促进,减轻了干旱胁迫对幼苗造成的伤害,提高了植株的整体抗旱性,而这种抗性与黄腐酸浓度呈明显相关性,0.05％ FA对植株的的保护效应最显著,而0.10％ FA则协同PEG加剧了对幼苗的伤害作用。     

棘孢木霉菌肥对黄瓜枯萎病的防治效果及对连作黄瓜根际土壤微生物种群的影响

为明确棘孢木霉Trichoderma asperellum菌肥在防治黄瓜枯萎病的同时对连作黄瓜根际土壤微生物种群的影响,采用实时荧光定量PCR(real-time fluorescence quantitative PCR,RT-qPCR)和磷脂脂肪酸(phospholipid fatty acid,PLFA)分析方法分别测定了棘孢木霉菌肥对连作4年的黄瓜根际棘孢木霉菌和尖孢镰孢菌Fusarium oxysporum DNA拷贝数变化和黄瓜根际微生物种群的影响。结果表明:棘孢木霉菌肥对黄瓜幼苗期和速长期黄瓜枯萎病的防治效果分别为70.24%和76.81%,均与药剂对照的防效差异不显著。棘孢木霉菌的DNA拷贝数出现2个高峰期,即黄瓜苗期和盛果期,其DNA拷贝数分别为235 000.00 ng/μL和80 500.00 ng/μL。黄瓜速长期、盛果期、生长末期的尖孢镰孢菌DNA拷贝数分别为15.41、54.87和18.36 ng/μL,且显著低于同一时期药剂对照和清水对照。黄瓜幼苗期、速长期、开花期和盛果期根际土壤微生物丰度分别为2.24、1.98、2.52和2.12,均高于药剂对照。由此可见,棘孢木霉菌肥在防治黄瓜枯萎病的同时,还可以改善黄瓜连作土壤微生物种群结构。     

茉莉酸处理菜豆对美洲斑潜蝇抗性的影响

为明确外源茉莉酸(JA)处理菜豆对美洲斑潜蝇抗性的诱导作用,采用生物测定和生化分析方法,研究了4种浓度JA喷施菜豆幼苗后,菜豆对美洲斑潜蝇的抗性及菜豆叶片过氧化物酶(POD)、多酚氧化酶(PPO)和脂氧合酶(LOX)活性的变化.结果表明,JA处理可以提高菜豆对美洲斑潜蝇的抗性及菜豆叶片3种防御酶的活性,且其抗性和防御酶活性提高程度均与JA浓度有关.0.1、1 mmol/L JA可显著降低美洲斑潜蝇成虫对菜豆的取食和产卵选择性,使卵或幼虫发育历期延长、幼虫取食量降低、蛹重减轻,而0.001和0.01 mmol/L JA仅对幼虫发育历期有显著影响.0.1 mmol/L JA处理后,菜豆叶片POD、PPO和LOX活性均显著升高,分别较对照增加33％、39％和80％,而0.001 mmol/L JA对菜豆叶片防御酶诱导作用不明显.     

孜然种子中杀菌活性成分分离及结构鉴定

以小麦白粉病菌Blumer graminis、黄瓜霜霉病菌Pseudoperonispora cubensis、杨树溃疡病菌Dothiorella gregaria、棉花枯萎病菌Fusarium oxysporum f.sp.vasinfectum、白菜黑斑病菌Alternaria oleracea和稻瘟病菌Pyricularia grisea 6种病原菌为指示菌种,对孜然种子中的杀菌活性成分进行了跟踪分离及活性测定。采用柱层析分离技术,从孜然种子乙醇浸膏石油醚萃取液中分离得到两个具有杀菌活性的化合物,其结构经质谱、核磁共振氢谱及碳谱等分析确定其分别为枯茗酸(对异丙基苯甲酸,p-isopropyl benzoic acid)和枯茗醛(对异丙基苯甲醛,p-isopropyl benzaldehyde)。采用菌丝生长速率法测定了两化合物对油菜菌核病菌Sclerotinia sclerotiorum和辣椒疫霉Phytophthora capsici的毒力,其中枯茗醛对两种病原菌的EC50值分别为2.093和 15.40 mg/L,枯茗酸的EC50值分别为7.298和19.66 mg/L。     

没食子酸对水稻细菌性条斑病防治作用的持效期

利用高效液相色谱法(HPLC)检测没食子酸(gallic acid,简称GA)在水稻叶片上的残留时间,并在检测水稻叶片上残留量的同时接种病原菌,调查接种后水稻细菌性条斑病的发病情况,以确定GA在水稻叶片上对水稻细菌性条斑病防治作用的持效期。研究结果表明,GA不具有内渗作用,只残留在水稻叶片的表面。分别用100、200和400 mg/L的浓度处理叶片后,GA在叶片表面的残留时间分别为16、24和28 d。200 mg/L浓度处理叶片后,GA对水稻细菌性条斑病防治作用的持效期为16 d。研究结果可为有效使用GA防治水稻细菌性条斑病奠定基础。