土壤水分胁迫下大麦籽粒形成期碳氮代谢及其互作效应

利用防雨棚研究了土壤水分胁迫对大麦籽粒形成期碳氮代谢生理特性的影响。结果表明：淀粉和蛋白质沉积的生理机制的明显差异是导致干旱胁迫下籽粒淀粉沉积降低、蛋白质积累增加的内在因素；同时，籽粒形成后期的碳氮代谢互作在竞争和能量方面的差异也对籽粒淀粉沉积减少、蛋白质含量增加起到了一定的作用。     

氮肥用量对啤酒大麦籽粒蛋白质和醇溶蛋白组分含量的影响及其与β-淀粉酶活性的关系

氮肥用量显著影响籽粒蛋白质含量、B醇溶蛋白和C醇溶蛋白组分含量，而对D醇溶蛋白组分含量的影响不显著；随着氮肥用量增加，籽粒蛋白质含量、B醇溶蛋白和C醇溶蛋白组分含量显著增加，D醇溶蛋白组分含量增加相对较少。品种对籽粒蛋白质含量、C和D醇溶蛋白组分含量的影响要比氮肥用量大，而B醇溶蛋白组分含量的差异主要是由氮肥用量的差异引起的。氮肥用量显著影响千粒重和β-淀粉酶活性，而对产量的影响不显著；随着氮肥用量增加，千粒重和β-淀粉酶活性显著增加，而产量的变化相对较小。品种对千粒重和β-淀粉酶活性的影响要比氮肥用量大。本研究中未发现β-淀粉酶活性和籽粒蛋白质含量之间的正相关关系，     

Study on the Inhibitory Activity of a Synthetic Defensin Derived from Barley Endosperm against Common Food Spoilage Yeast

In the food industry, food spoilage is a real issue that can lead to a significant amount of waste. Although current preservation techniques are being applied to reduce the occurrence of spoilage microorganisms, the problem persists. Food spoilage yeast are part of this dilemma, with common spoilers such as Zygosaccharomyces, Kluyveromyces, Debaryomyces and Saccharomyces frequently encountered. Antimicrobial peptides derived from plants have risen in popularity due to their ability to reduce spoilage. This study examines the potential application of a synthetic defensin peptide derived from barley endosperm. Its inhibitory effect against common spoilage yeasts, its mechanisms of action (membrane permeabilisation and overproduction of reactive oxygen species), and its stability in different conditions were characterised. The safety of the peptide was evaluated through a haemolysis and cytotoxicity assay, and no adverse effects were found. Both assays were performed to understand the effect of the peptide if it were to be consumed. Its ability to be degraded by a digestive enzyme was also examined for its safety. Finally, the peptide was successfully applied to different beverages and maintained the same inhibitory effects in apple juice as was observed in the antiyeast assays, providing further support for its application in food preservation.     

Projection structure of photosystem II In vivo determined by cryo-electron crystallography

Photosystem II (PSII) is a protein-pigment complex situated in the thylakoid membranes of plants and cyanobacteria where it catalyses the conversion of light into chemical energy. This energy is used to extract electrons from water, during which process oxygen is evolved. Owing to its extreme fragility and the large number of polypeptides (>20) it is composed of, the complex has so far proven recalcitrant to high-resolution structural studies. Cryo-electron crystallography of 2-D crystals (a = 15.4 nm, b = 23.1 nm, γ = 97.2°, p1) comprising in situ PSII revealed the first projection structure of the native complex. The unit cell contain one monomeric complex in which three central domains straddle an elongated intramolecular cavity. In conjunction with earlier data, these central domains were assigned to the reaction centre core subunits of PSII consisting of CP43, CP47, the reaction centre heterodimer D1/D2 and cytochrome b-559. The data are discussed in view of the evolution of reaction centres from anoxygenic to oxygenic photosynthesis.     

大麦应用三十烷醇磷酸酯钾田间试验初报

田间喷施 0. 01mg/L 的三十烷醇磷酸酯钾或 0. 5mg/L 的三十烷醇都能显著改善同源四倍体大麦的 产量性状且改善的程度相当,使穗颈长度从 2. 4cm 延长到 3. 7cm, 减少包颈的发生率, 穗重从 1. 145g 提 高到 1. 338g,结实率从 75. 0%提高到 79. 5%, 千粒重从 43. 638g 增加到 50. 031g.     

大麦酯酶同工酶酶谱的聚类分析与遗传研究

采用聚丙烯酰胺凝胶电泳对主要产于我国不同地区的３３份近缘野生大麦及其１９份栽培大麦，以及它们间杂交的２７个组合Ｆ１植株的叶片进行了酯酶同工酶分析．结果表明，５２份材料可分成１１个酶谱类型，聚类分析说明，同一亚种或同一变种，地理来源不同，酶谱表现不同．地理来源相同或相近的不同亚种或不同变种，酯酶同工酶酶谱一般表现出相同或相近．杂交组合Ｆ１中酶谱出现３种类型：偏亲本型，杂种型和互补型．其中以互补型为多．凡出现杂种酶带或互补酶带的植株，在穗长和株高上都表现出杂种优势的特征．对近缘野生大麦和栽培大麦的酶谱以及与地理距离的关系和酯酶同工酶在大麦中的应用进行了讨论．     

酸铝对大麦不同耐性品种形态,生长及元素吸收的影响

通过对耐酸铝性不同的两个大麦品种进行耐酸铝性鉴定表明，两品种的苗高、根长及干重受到的影响均存在显著差异。经酸铝培养液处理后，敏感品种“嵊县无芒六棱”体内铝元素含量显著增加，而营养元素的含量却明显降低。     

大麦籽粒蛋白质及其组分含量的遗传研究

用７个蛋白质含量不同的品种，以不完全双列杂交的酱模式配成１２个Ｆ１，对大麦籽粒蛋白质及其四种组分含量这五个性状的遗传参数进行了研究。结果表明，醇溶蛋白含量主要由加性效应控制，蛋白质和谷蛋白含量主要由非加性效应控制；球蛋白和清蛋白含量是由加性和非加性效应共同控制的，但对不同的性状，二者所起遥作用是不等的。     

Effect of inhibitors released during steam-explosion pretreatment of barley straw on enzymatic hydrolysis

The influence of the liquid fraction (prehydrolysate) generated during steam-explosion pretreatment (210°C, 15 min) of barley straw on the enzymatic hydrolysis was determined. Prehydrolysate was analyzed for degradation compounds and sugars' content and used as a medium for enzymatic hydrolysis tests after pH adjusting to 4.8. Our results show that the presence of the compounds contained in the prehydrolysate strongly affects the hydrolysis step (a 25% decrease in cellulose conversion compared with control). Sugars are shown to be more potent inhibitors of enzymatic hydrolysis than degradation products.