Biosynthesis of vitamin B12 by Propionibacterium freudenreichii subsp. shermanii ATCC 13673 using liquid acid protein residue of soybean as culture medium

Vitamin B12 deficiency still persists, mainly caused by low intake of animal food products affecting vegetarians, vegans, and populations of underdeveloped countries. In this study, we investigate the biosynthesis of vitamin B12 by potential probiotic bacterium using an agroindustry residue, the liquid acid protein residue of soybean (LAPRS), as a low-cost, animal derivate-free alternative culture medium. Cultures of Propionibacterium freudenreichii subsp. shermanii ATCC 13673 growing in LAPRS for vitamin B12 biosynthesis were studied using the Plackett–Burman experimental approach, followed by a central composite design 2² to optimize the concentration of significant variables. We also performed a proteolytic treatment of LAPRS and evaluated the optimized–hydrolyzed medium influence on the microbial growth and metabolism in shaker flask and bioreactor experiments. In this all-plant source medium, P. freudenreichii subsp. shermanii produced high concentrations of cells and high amounts of vitamin B12 (0.6 mg/g cells) after process optimization. These results suggest the possibility of producing vitamin B12 by a potential probiotic bacterium in a very cheap, animal derivate-free medium to address the needs of specific population groups, at the same time reducing the production costs of this essential vitamin.     

Soybean ferritin: isolation, characterization, and free radical generation

The main aim of this work was to assess the multi-task role of ferritin(Ft)in the oxidative metabolism of soybean(Glycine max).Soybean seeds incubated for 24 h yielded 41 ± 5 μg Ft/g fresh weight.The rate of in vitro incorporation of iron(Fe)into Ft was tested by supplementing the reaction medium with physiological Fe chelators.The control rate,observed in the presence of 100 μM Fe,was not significantly different from the values observed in the presence of 100 μM Fe-his.However,it was significantly higher in the presence of 100 μM Fe-citrate(approximately 4.5-fold)or of 100 μM Fe-ATP(approximately 14-fold).Moreover,a substantial decrease in the Trp-dependent fluorescence of the Ft protein was determined during Fe uptake from Fe-citrate,as compared with the control.On the other hand,Ft addition to homogenates from soybean embryonic axes reduced endogenously generated ascorbyl radical,according to its capacity for Fe uptake.The data presented here suggest that Ft could be involved in the generation of free radicals,such as hydroxyl radical,by Fe-catalyzed reactions.Moreover,the scavenging of these radicals by Ft itself could then lead to protein damage.However,Ft could also prevent cellular damage by the uptake of catalytically active Fe.     

Dehydrin expression in seeds and maturation drying: a paradigm change

Dehydrins are well known for being expressed in leaves during the course of developmental processes as well as under drought stress, being part of the protective machinery. Moreover, in seed physiology, dehydrins are classified as late embryogenesis‐related proteins (LEA protein), where they are thought to be responsible for persistence and longevity of seeds. Although both topics are a focus of modern plant biology, a direct linkage between these both areas is generally lacking. Based on an alignment of the chain of events, this paper will help to generate understanding that the occurrence of dehydrins in maturing seeds and leaves suffering drought stress is part of the same basic principle: basic principle: dehydrins are expressed in response to water shortage. Unfortunately, the related developmental process in seeds, i.e. maturation drying, has not been adequately considered as a part of this process. As a corresponding implication, the chain of events must be adjusted: the differences in dehydrin expression in orthodox, intermediate and recalcitrant seeds could be directly attributed to the occurrence or absence of maturation drying. The differences in dehydrin expression in orthodox, intermediate and recalcitrant seeds, and thus the differences in longevity, could be attributed to the occurrence or absence of a maturation drying.     

Mapping QTLs for seed yield and drought susceptibility index in soy-bean（Glycine max L.） across different environments

Drought stress has long been a major constraint in maintaining yield stability of soybean （Glycine max （L.） Merr.） in rainfed ecosystems. The identification of consistent quantitative trait loci （QTL） involving seed yield per plant （YP） and drought susceptibility index （DSI） in a population across different environments would therefore be important in molecular marker-assisted breeding of soybean cultivars suitable for rainfed regions. The YP of a recombinant line population of 184 F2：7：11 lines from a cross of Kefengl and Nannong1138-2 was studied under water-stressed （WS） and well-watered （WW） conditions in field （F） and greenhouse （G） trials, and DSI for yield was calculated in two trials. Nineteen QTLs associated with YP-WS and YP-WW, and 10 QTLs associated with DSI, were identi- fied. Comparison of these QTL locations with previous findings showed that the majority of these regions control one or more traits re- lated to yield and other agronomic traits. One QTL on molecular linkage group （MLG） K for YP-F, and two QTLs on MLG C2 for YP-G, remained constant across different water regimes. The regions on MLG C2 for YP-WW-F and MLG H for YP-WS-F had a pleiotropic effect on DSI-F, and MLG A1 for YP-WS-G had a pleiotropic effect on DSI-G. The identification of consistent QTLs for YP and DSI across different environments will significantly improve the efficiency of selecting for drought tolerance in soybean.     

桔核中柠檬苦素类物质消炎镇痛作用的研究

为探讨柑桔果实中柠檬苦素类物质对实验动物模型的抗炎镇痛作用,本文通过小鼠耳廓肿胀模型和角叉菜胶致大鼠足肿胀模型观察柠檬苦素的抗炎作用;采用小鼠福尔马林实验及扭体实验观察柠檬苦素的镇痛作用。结果表明：柑桔果实中柠檬苦素类物质能显著抑制二甲苯致小鼠耳廓肿胀和角叉菜胶致大鼠足肿胀程度;减少扭体次数;显著提高小鼠福尔马林实验中的痛域。因此,柑桔果实中柠檬苦素类物质对本实验中的动物模型具有显著的抗炎及镇痛作用。     

大豆低聚糖对小鼠体液免疫功能的影响试验研究

通过利用大豆低聚糖对小鼠灌服后溶血素生成量的测定,阐明大豆低聚糖对小鼠体液免疫功能的影响。     

N-(2-吡啶基)-N'-苯基脲对几种作物种子根、芽生长影响的回归分析

N-（2-吡啶基）-N'-苯基脲（2PU）,属苯基脲衍生物,具有细胞分裂素活性,有关其合成和应用的研究未见报道。作者合成了2PU并进行了生物效应试验研究。结果表明,2PU对作物种子萌发时胚根、胚芽的生长具有明显的促进作用,其根、芽生长与2PU浓度之间的关系符合Y=a＋bX＋eX2＋的数学模型。2PU对小麦根芽和赤豆根芽生长最佳浓度分别是0.001～0.0lppm、0.005～0.05ppm,对黄豆根生长以0.001～0.06ppm最佳。     

Brassinosteroids promote development of rice pollen grains and seeds by triggering expression of Carbon Starved Anther,a MYB domain protein

Transport of photoassimilates from leaf tissues (source regions) to the sink organs is essential for plant development. Here, we show that a phytohormone, the brassinosteroids (BRs) promotes pollen and seed development in rice by directly promoting expression of Carbon Starved Anther (CSA) which encodes a MYB domain protein. Over‐expression of the BR‐synthesis gene D11 or a BR‐signaling factor OsBZR1 results in higher sugar accumulation in developing anthers and seeds, as well as higher grain yield compared with control non‐transgenic plants. Conversely, knockdown of D11 or OsBZR1 expression causes defective pollen maturation and reduced seed size and weight, with less accumulation of starch in comparison with the control. Mechanically, OsBZR1 directly promotes CSA expression and CSA directly triggers expression of sugar partitioning and metabolic genes during pollen and seed development. These findings provide insight into how BRs enhance plant reproduction and grain yield in an important agricultural crop.     

荔枝核的五个苷类成分

通过溶剂分部和多种色谱分离,从荔枝(Litchi chinensis Sonn.)核中得到5个苷类成分。经光谱分析及与文献数据对照,分别鉴定为(-)-松脂素4-O-β- D-吡喃葡萄糖苷 (1)、苯乙基β- D-吡喃葡萄糖苷 (2)、乙基β- D-吡喃葡萄糖苷 (3)、乙基α- D-吡喃葡萄糖苷 (4)和胞苷 (5)。它们均为首次从荔枝核中分离得到。     

藜异型性种子后代植株盐响应生理机制

种子异型性是植物适应异质生境的重要策略,异型性对后代植株的影响值得深入研究。以具有种子异型性的荒漠植物藜为材料,测定了异型种子后代植株在不同浓度(0,50,300 mmol/L)Na Cl胁迫下的表型及与耐盐相关的生理指标变化,探讨了异型种子后代植株之间对盐胁迫生理响应机制的差异。结果显示,褐色种子后代植株在各浓度盐胁迫下的表型(株高、分枝数)均优于黑色种子。对其生理指标测定结果显示,褐色种子植株除电导率显著低于黑色种子植株外,氧化损伤指标(氧自由基、丙二醛含量)及抗氧化酶(SOD、CAT、POX)活性、抗氧化剂(Car、As A)含量、渗调物质(可溶性糖、脯氨酸、甜菜碱)含量等在两者之间无明显差异。研究结果暗示,藜异型性种子后代植株的早期生长表型在盐胁迫下所产生的差异可能是由种子胚的大小及萌发快慢差异所导致,而这种差异并未引起盐胁迫下两种植株抗氧化系统响应的差异。