Plant Growth Promoting Rhizobacteria Having 1-Aminocyclopropane-1-Carboxylic Acid Deaminase to Induce Salt Tolerance in Sunflower (<i>Helianthus annus L.</i>)

Soil salinity badly affects agriculture productivity through accumulation of salts in upper layers of soils. The harmful effects of salts in arable lands have influenced modern as well as ancient civilizations. A pot study was carried out to test the performance of two PGPR isolates (KS 8, KS 28) on sunflower (SMH-0917) under different salinity levels (8, 10 and 12 dS·m-1). These salinity levels were developed by adding calculated amount of salts (NaCl, Na2SO4, CaCl2 and MgSO4) with ratio of 3:4:2:1. The bacterial strains KS 8 and KS 28 were applied separately in two treatments while third treatment was co-inoculation (KS mix). Completely randomized experimental design (CRD) was used and data were collected at flowering stage about pre-decided plant growth parameters (plant height, shoot dry weight and root dry weight). The bacterial isolate KS 8 showed an increase of 26, 102% and 83% in plant height, shoot dry weight and root dry weight at EC 8 dS·m-1, while this improvement was 67%, 163% and 296% at EC 10 dS·m-1, however an increase of 100%, 74% and 382% was recorded over control respectively at EC 12 dS·m-1. Similarly isolate KS 28 exhibited an increase of 14%, 69% and 54% in plant height;shoot dry weight and root dry weight at EC 8 dS·m-1, whereas this improvement was 56%, 163% and 188% at EC 10 dS·m-1, while an increase of 60%, 41% and 282% was registered respectively over control at EC 12 dS·m-1. The increase due to mixture treatments was 4%, 41% and 16% in plant height, shoot dry weight and root dry weight at EC 8 dS·m-1, while an increase of 33%, 57% and 100% at EC 10 dS·m-1, whereas an improvement of 53%, 33% and 164% respectively was noted at EC 12 dS·m-1 over un-inoculated. The isolate KS 8 performed better than KS 28 and mixture treatment. These two PGPR strains could be used to mitigate the adverse impact caused by salinity stress on sunflower.

Relationships of Ethylene Evolution Rate and 1-Aminocylopropane-1-Carboxylic Acid Concentration in Grains during Filling Period with Appearance Quality of Rice

To elucidate the relationship between ethylene evolution from the grains and the appearance quality of rice, ten different rice genotypes were used to determine the ethylene evolution rate, 1-aminocylopropane-1-carboxylic acid （ACC） concentration in grains during grain filling and the appearance quality of rice, and the effects of chemical regulators on concentrations of ethylene and ACC in the grains during grain filling were also investigated to verify the roles of ethylene in the rice quality formation. The ethylene evolution rates and ACC concentrations in grains during the mid and late grain filling stages were very significantly and positively correlated with chalky kernel percentage and chalkiness. The cultivars with a low ACC concentration in grains exhibited a close amyloplast arrangement and small space between starch granules, whereas those with a high ACC concentration in grains showed a loose arrangement and wide space between the granules. Application of 1 μmol/L ACC to panicles at mid and late grain filling stages significantly loosened amyloplast arrangement and increased chalky kernel percentage, chalky area and chalkiness, and the results were reversed when 1 μmol/L amino-ethoxyvinylglycine, an inhibitor of ACC synthesis enzyme, was applied to panicles. A practice of moderate dry-wet alternate irrigation reduced ethylene evolution and ACC concentration in grains and thereby reduced chalkiness. The results suggested that ethylene and ACC in grains play an important role in the endosperm structure and appearance quality of rice, and the appearance quality would be improved by reducing ethylene evolution and ACC in grains through either variety breeding and selection, or chemical regulations or cultivation techniques.

Synthesis and Crystal Structure of 1-H-Pyrrole-2-carboxylic Acid [2-(Naphthalen-1-ylamino)-ethyl]-amide

1-H-Pyrrole-2-carboxylic acid [2-（naphthalen-1-ylamino）-ethyl]-amide has been synthesized and characterized. Its crystal is of monoclinic, space group P2 1/n with a = 5.930（6）, b = 12.144（13）, c = 20.10（2） , A, β = 95.709（17）°, V= 1441（3） ,A, Z= 4, C17H17N3O, Mr= 279.34, Dc= 1.288 g/cm^3, F（000） = 592, μ（MoKa） = 0.083 mm^-1, S = 1.019, R = 0.0473 and wR = 0.1181 for 1713 observed reflections with I 〉 2 σ（I）. X-ray diffraction reveals that two molecules of the title compound form a dimer through a pair of N-H…O hydrogen bonds.

3,6-dichlorobenzo[b]thiophene-2-carboxylic acid alleviates ulcerative colitis by suppressing mammalian target of rapamycin complex 1 activation and regulating intestinal microbiota

BACKGROUND 3,6-dichlorobenzo[b]thiophene-2-carboxylic acid(BT2)is a benzothiophene carboxylate derivative that can suppress the catabolism of branched-chain amino acid(BCAA)-associated mammalian target of rapamycin complex 1(mTORC1)activation.Previous studies have demonstrated the therapeutic effects of BT2 on arthritis,liver cancer,and kidney injury.However,the effects of BT2 on ulcerative colitis(UC)are unknown.AIM To investigate the anti-UC effects of BT2 and the underlying mechanism.METHODS Mouse UC models were created through the administration of 3.5%dextran sodium sulfate(DSS)for 7 d.The mice in the treated groups were administered salazosulfapyridine(300 mg/kg)or BT2(20 mg/kg)orally from day 1 to day 7.At the end of the study,all of the mice were sacrificed,and colon tissues were removed for hematoxylin and eosin staining,immunoblot analyses,and immunohistochemical assays.Cytokine levels were measured by flow cytometry.The contents of BCAAs including valine,leucine,and isoleucine,in mouse serum were detected by liquid chromatography-tandem mass spectrometry,and the abundance of intestinal flora was analyzed by 16S ribosomal DNA sequencing.RESULTS Our results revealed that BT2 significantly ameliorated the inflammatory symptoms and pathological damage induced by DSS in mice.BT2 also reduced the production of the proinflammatory cytokines interleukin 6(IL-6),IL-9,and IL-2 and increased the anti-inflammatory cytokine IL-10 level.In addition,BT2 notably improved BCAA catabolism and suppressed mTORC1 activation and cyclooxygenase-2 expression in the colon tissues of UC mice.Furthermore,highthroughput sequencing revealed that BT2 restored the gut microbial abundance and diversity in mice with colitis.Compared with the DSS group,BT2 treatment increased the ratio of Firmicutes to Bacteroidetes and decreased the abundance of Enterobacteriaceae and Escherichia-Shigella.CONCLUSION Our results indicated that BT2 significantly ameliorated DSS-induced UC and that the latent mechanism involved the suppression of BCAA-associated mTORC1 activation and modulation of the intestinal flora.

丹红注射液对高脂血症大鼠肝脏AMPK/SREBP-1/ACC通路的影响

目的探讨丹红注射液(Danhong injection,DHI)对大鼠高脂血症的作用及机制。方法采用高脂饲料制备大鼠高脂血症模型,检测各组大鼠肝脏腺苷酸激活蛋白激酶(AMPK)、p-AMPK、胆固醇调节元件结合蛋白(SREBP-1)、乙酰辅酶A羧化酶(ACC)、p-ACC的蛋白表达水平。结果给予丹红注射液后,肝脏AMPK、SREBP-1和ACC的蛋白表达水平明显降低(P<0.05),p-ACC和p-AMPK的蛋白表达水平明显升高(P<0.05)。结论丹红注射液通过增强AMPK的活化,抑制SREBP-1和ACC的活性,促进脂肪酸氧化,减少脂质沉积,有效降低了高脂血症大鼠的血脂水平。

假单胞菌株M18分泌羧基吩嗪抑制黄瓜枯萎病害

设计并应用新的高效筛选程序 ,从植物根际土壤分离出同时具有促进植物生长和抑制黄瓜枯萎病害的假单胞菌株 M1 8.它对黄瓜幼苗的根系具有明显的促进作用 ,在培养皿中 ,M1 8能有效地抑制黄瓜枯萎病菌以及多种其他植物病原菌菌丝体的生长 .经 M1 8活菌浸种处理春黄瓜种子并在大棚内浇灌定植后的根际土壤 ,与对照相比 ,黄瓜枯萎病的株发病率降低 70 %～ 80 % ,霜霉病的发病率和病情指数都同时平均下降 70 %左右 ,黄瓜产量提高 2 0 %以上 .M1 8的生物防治效果达到极显著程度 .对培养液中纯化的抗真菌物质进行光谱分析和 LC- MC测定的结果表明 ,M1

Isolation and identifi cation of antimicrobial metabolites from sea anemone-derived fungus Emericella sp.SMA01

Marine symbiotic fungi represent an intriguing source of discovery of novel secondary metabolites with various biological activities.Sea anemones are benthic marine invertebrates,however,the cultivable symbiotic fungi residing in the sea anemones are paid few attentions compared to those derived from their cnidarian counterparts.Here we show the identification of antimicrobial secondary metabolites from the sea anemone-derived symbiotic fungi.Out offive isolated fungal strains,only the strain SMA01 showed strong antimicrobial activities,which was assigned into the genus Emericella based on the morphological characteristics and the ITS sequencing.Media swift from liquid fermentation to solid rice medium presented little influence on its antibacterial activity.A chemical investigation of the ethyl acetate extract of the Emericella sp.SMA01 led to discovery of the primary antibiotic metabolite phenazine-1-carboxylic acid.The IC_(50) values of the phenazine-1-carboxylic acid against Phytophthora capsici,Gibberella zeae,and Verticillium dahliae were determined to be 23.26-53.89μg/mL.To the best of our knowledge,this was the first report of Emericella sp.in sea anemones.The current study may benefit understanding of the defensive chemical interactions between the symbiotic fungi and their host sea anemones.

Hydrothermal Synthesis and Crystal Structure of One Novel 1-D Copper(Ⅱ)-organic Framework:{[Cu_2(PP)_2(CBPC)]_2·7H_2O}_n

One novel 1-D copper（Ⅱ）-organic compound,namely {[Cu2（PP）2（CBPC）]2·7H2O}n（1,H2CBPC=1-[（2＇-carboxybiphenyl-4-yl）methyl]-2-propylimidazole-4-carboxylic acid,HPP=3-（2-pyridyl）pyrazole）,was synthesized under hydrothermal conditions.X-ray diffraction analyses reveal that the two Cu（Ⅱ） ions in the distorted dimer [Cu2（PP）2] of 1 are linked by the carboxylate oxygen atoms on the phenyl and imidazole rings,respectively,forming one interesting snake-like chain.Single-crystal X-ray analyses reveal that it crystallizes in monoclinic,space group C2/c with a=30.656（8）,b=12.715（3）,c=22.405（5）,β=122.758（3）°,V=7344（3）3,Z=4,Mr=1681.65,Dc=1.521 g/cm3,F（000）=3464,μ=1.221 mm-1,the final R=0.0453 and wR=0.1023 for 4617 observed reflections with Ⅰ 〉2σ（Ⅰ）.

Las-like quorum-sensing system negatively regulates both pyoluteorin and phenazine-1-carboxylic acid production in Pseudomonas sp. M18

A las-like quorum-sensing system in Pseudomonas sp. M18 was identified, which consisted of lasI and lasR genes encoding LuxI-LuxR type regulator. Several functions of the las system from strain M18 were investigated in this study. The chromosomal inactivation of either lasI or lasR by recombination increased the production of both pyoluteorin (Plt) and phenazine-1-carboxylic acid (PCA) by 4-5 fold and 2-3 fold over that of the wild type strain of M18, respectively. Production of both antibiotics was restored to wild-type levels after in trans complementation with the wild-type lasI or lasR gene. Expression of the translational fusions pltA'-'lacZ and phzA'-'lacZ further confirmed the negative effect of lasI or lasR on both biosynthetic operons, and it was also demonstrated that the las system was related to the ability of swarming motility and the inhibition of cell growth.

H-NS family protein MvaU downregulates phenazine-1-carboxylic acid(PCA)biosynthesis via binding to an AT-rich region within the promoter of the phz2 gene cluster in the rhizobacterium Pseudomonas strain PA1201

Histone-like nucleoid-structuring(H-NS)proteins are key regulators in gene expression silencing and in nucleoid compaction.The H-NS family member proteins MvaU in Pseudomonas aeruginosa are thought to bind the same AT-rich regions of chromosomes and function to coordinate the control of a common set of genes.Here,we explored the molecular mechanism by which MvaU controls PCA biosynthesis in P.aeruginosa PA1201.We present evidence suggesting that MvaU is self-regulated.Deletion of mvaU significantly increased PCA production,and PCA production sharply decreased when mvaU was over-expressed.MvaU transcriptionally repressed phz2 cluster expression and consequently reduced PCA biosynthesis.β-galactosidase assays confirmed that base pairing near the35 box is required when MvaU regulates PCA production in PA1201.Electrophoretic mobility shift assays(EMSA)and additional point mutation analysis demonstrated that MvaU directly bound to an AT-rich motif within the promoter of the phz2 cluster.Chromatin immunoprecipitation(ChIP)analysis also indicated that MvaU directly bound to the P5 region of the phz2 cluster promoter.MvaU repression of PCA biosynthesis was independent of QscR and OxyR in PA1201 and neither PCA or H2O2 were the environmental signals that induced mvaU expression.These findings detail a new MvaU-dependent regulatory pathway of PCA biosynthesis in PA1201 and provide a foundation to increase PCA fermentation titer by genetic engineering.

水稻籽粒中乙烯和ACC对土壤水分的反应及其与籽粒灌浆的关系

以武运粳8号(粳稻)和扬稻6号(籼稻)为材料,自抽穗后9d至成熟期进行保持浅水层(WW)、土壤轻度落干(MD)和土壤水分严重亏缺(SD)3种处理。观察在不同土壤水分条件下灌浆期籽粒中乙烯和1-氨基环丙烷-1-羧酸(ACC)浓度的变化及其与籽粒灌浆的关系,并使用化学调控物质进行验证。结果表明,MD显著提高籽粒灌浆速率和粒重,SD明显降低籽粒灌浆速率和粒重。籽粒中乙烯释放速率和ACC浓度在MD中降低,在SD中增加。籽粒乙烯释放速率及根系伤流液中ACC浓度与籽粒中ACC浓度呈极显著的正相关。籽粒灌浆速率与乙烯释放速率呈极显著负相关。在花后9～13d喷施乙烯合成的抑制物质氨基-乙氧基乙烯基甘氨酸(AVG),明显降低籽粒中ACC的浓度和乙烯的释放速率,显著提高了籽粒灌浆速率和粒重以及籽粒中的蔗糖合成酶(SuSase)、ADP葡萄糖焦磷酸化酶(AGPase)和可溶性淀粉合成酶(SSSase)活性;喷施乙烯释放的促进物质乙烯利,结果则相反。表明结实期土壤轻度落干或适度干旱处理可以抑制水稻体内乙烯的产生,促进籽粒灌浆。

乙烯抑制剂AVG和促进剂ACC对大豆幼苗叶片光合特征的影响

采用不同浓度乙烯抑制剂氨基乙氧基乙烯甘氨酸(aminoethoxyvinylglycine,AVG)和促进剂1-氨基环丙烷-1-羧酸(1-aminocylopropane-1-carboxylic acid,ACC)对盆栽大豆幼苗进行处理,探讨其对光响应曲线、CO2响应曲线等光合特性的影响.结果表明:与对照相比,AVG处理明显提高了大豆幼苗叶片净光合速率、蒸腾速率和气孔导度,降低了胞间CO2浓度;明显提高了光饱和点、光饱和光合速率、表观量子效率、CO2饱和点、羧化效率、RuBP最大再生速率,同时,降低了光补偿点和CO2补偿点;此外,AVG处理还提高了大豆幼苗生物量和叶面积,降低了叶片乙烯释放量、叶绿素含量与气孔密度;ACC处理的效果与AVG相反.以上结果表明,外源AVG处理能改善大豆幼苗叶片的光合性能.

Drug discovery based on the structure of FKBP12: Design, synthesis and evaluation of L-1,4-thiazane-3-carboxylic acid derivatives as neuroimmunophilin ligands

By choosing neuroimmunophilin FKBP12 as a therapeutical target, we have attempted to discover a new structural drug for treating neurodegenerative disease. This drug should possess neurotrophic activity and not affect the immune system. Based on the crystal structure of FKBP12, FK506 and Calcineurin complex, a series of small organic molecules were designed. These molecules were to have the ability of binding to FKBP12 in a virtual screening. By using a solution parallel synthetic method, these compounds were synthesized. The neuroprotective and neuroregenerative activities of these compounds were evaluated by binding assays, PC12 cells survival and neurite outgrowth model, chick dorsal root ganglion cultures (DRG) and 6-OHDA lesioned mice sympathetic nerve endings model. The evaluation results of these compounds showed that compound N308 has great promise as a candidate for a neuroprotective and neuroregenerative agent.

温度对采后梨果实多胺、ACC含量、EFE活性和乙烯生成量的影响

测定了两个日本梨品种菊水和二十世纪(Pyrus serotina Rehder var.culta.Rehder)在30、15和5℃贮藏温度下,多胺、ACC含量、EFE活性和乙烯释放速率的变化。1.15和5℃低温可显著抑制梨果实内EFE活性,乙烯生成速率显著降低;2.两品种对低温的敏感性存在差异,15℃低温处理既能减少二十世纪梨的乙烯生成速率,也能抑制乙烯释放高峰的出现,而同样的温度处理仅能减少菊水梨的乙烯生成速率,不能抑制乙烯释放高峰的出现;3.在15和5℃处理下,两品种果实内ACC含量和丁二胺含量均呈上升趋势,5℃处理比15℃处理明显;4.梨果实内含有3种多胺,其中以丁二胺和亚精胺为主,丁二胺与梨果实内乙烯生物合成的抑制作用有密切关系;5.品种间在EFE活性、ACC含量和多胺含量上的差异决定了它们在乙烯生成速率上的差异。

Isolation of a Tomato Protease that May Be Involved in Proteolysis of 1-Aminocyclopropane-l-Carboxylate Synthase

1-aminocyclopropane- 1-carboxylate （ACC） synthase is a principal enzyme that catalyses the committed step in phytohormone ethylene biosynthesis. Previous evidence indicates that the hypervariable C-terminus of ACC synthase is most likely to be processed proteolytically in vivo. However, the protease responsible has not been identified thus far. In the present study, we detected proteolytic activity against ACC synthase （LeACS2） in tomato （Lycopersicon esculentum Mill.） fruit extract based on a newly established in vitro assay system. Purification of the protease through DEAE, gel filtration and MonoQ chromatography resulted in considerable enrichment of a 64-kDa protein species. Subsequent biochemical analysis of the purified tomato protease revealed that the optimal conditions for its proteolytic activity were at pH 8.0 and at 37 ~C. In addition, the protease activity was blocked completely by the metalloprotease inhibitor 1,10-phenanthroline. The present study represents the first report on the isolation of an ACC synthase- processing protease from plant tissues.

Mutation in the gene encoding 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4) led to andromonoecy in watermelon

Summary Although it has been reported previously that ethylene plays a critical role in sex determination in cucurbit species, how the andromonoecy that carries both the male and hermaphroditic flowers is determined in watermelon is still unknown. Here we showed that the watermelon gene 1-aminocyclopropane-1-carboxylate syn- thase 4 CCitACS4）, expressed specifically in carpel primor- dia, determines the andromonoecy in watermelon. Among four single nucleotide polymorphism （SNPs） and one lnDel identified in the coding region of CitACS4, the C364W mutation located in the conserved box 6 was co- segregated with andromonoecy. Enzymatic analyses showed that the C364W mutation caused a reduced activity in CitACS4. We believe that the reduced CitACS4 activity may hamper the programmed cell death in stamen primordia, leading to the formation of hermaphroditic flowers.

Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.

固—液相转移法合成ACC

本文提出了一个用固-液相转移法合成植物生长调节剂ACC的新法,并对其中影响产率的诸因素进行了讨论,同时对该反应的机理进行了讨论。

BZL方对游离脂肪酸诱导HepG2细胞脂肪沉积和LKB1-AMPK-ACC信号传导通路的影响

目的:研究"祛湿化瘀方"中3种已被认知的、能被分离提取的有效组分(白术多糖、栀子苷、绿原酸)组成的BZL复方对体外肝脂毒性模型脂肪沉积和LKB1-AMPK-ACC信号传导通路的影响,以进一步探讨BZL方防治脂肪肝的作用机制。方法:建立游离脂肪酸诱导的HepG2细胞脂肪变性模型,设正常组、模型组和不同浓度药物血清组分别观察细胞上清液中的细胞内甘油三酯(TG)含量,细胞油红O染色,细胞的P-LKB1、P-AMPKα、P-ACC蛋白表达及LKB1、AMPKα、ACC基因表达。结果:FFA刺激24h后,模型组细胞内脂肪沉积明显,其TG含量明显高于正常组(P<0.01),细胞内P-LKB1、P-AMPK、P-ACC的蛋白表达均减弱,LKB1、AMPK、ACC的mRNA表达均明显减弱,而BZL方高剂量组细胞内TG含量显著低于模型组(P<0.01),其脂肪沉积与模型组相比也明显减轻;与模型组比较,BZL药物血清组细胞内P-LKB1、P-AMPKα、P-ACC的蛋白表达均明显增强(P<0.05,P<0.01),LKB1、AMPKα、ACC的mRNA表达也均明显增强(P<0.05,P<0.01)。结论:BZL方对FFA诱导的HepG2细胞脂肪沉积有显著的抑制作用,且呈剂量依赖关系,激活LKB1-AMPK-ACC信号传导通路可能是BZL方防治非酒精性脂肪性肝病的重要作用机制之一。

辣椒根际促生菌的分离筛选及生物育苗基质研制

[目的]将根际促生菌(plant growth-promoting rhizobacteria,PGPR)与普通育苗基质联合,研制成生物育苗基质,进而促进功能菌株苗期的根际定殖和移苗后促生功能的发挥。[方法]利用从辣椒根际分离筛选的产IAA和ACC脱氨酶菌株,保活添加至普通育苗基质研制成生物育苗基质,通过比较育苗效果筛选出生物育苗基质的最佳配伍菌株。[结果]从辣椒根际分离获得6株IAA产生量大于5 mg·L-1的菌株,其中菌株NJAU-G10、NJAU-N5和NJAU-N1同时能产ACC脱氨酶,且能力高于其他菌株;两季苗盘育苗试验结果表明,添加菌株NJAU-G10的生物基质,表现出较其他菌株更为突出的根际定殖和促进幼苗生长的能力,并确定其最佳接种量为5%;盆栽试验结果表明,菌株NJAU-G10在移苗后对辣椒的生长仍具有显著的促进作用,且能够有效地在根际定殖;结合形态、生理生化特征和16S r DNA基因序列分析,初步鉴定菌株NJAU-G10为枯草芽孢杆菌。[结论]分离获得一株枯草芽孢杆菌NJAU-G10,添加其研制的生物育苗基质能够有效促进辣椒苗盘期种苗及其移栽后的生长,研究结果能够为含PGPR蔬菜育苗基质的开发提供理论支撑,同时为PGPR新产品的开发提供新的思路。