The Effect of Acid Stress Treatment on Viability and Membrane Fatty Acid Composition of Oenococcus oeni SD-2a

To obtain ready-to-use wine malolactic starter cultures with high viability, the effects of acid stress treatments on the growth, inoculation viability, freeze-drying viability, and membrane fatty acid composition of the native Oenococcus oeni SD-2a strain were studied. The results showed that pH 3.5 and 3.2 adaptive treatments did not strongly decrease cell biomass but increased distinctly inoculation viability and freeze-drying viability. Concerning the membrane fatty acid composition, it was observed that acid stress conditions increased significantly the relative concentration of lactobacillic acid （C19cycl 1） and the unsaturated：saturated fatty acid ratio in cell membrane lipids. We assumed that acid-induced cross protective responses could be used in preparing ready-to-use O. oeni SD-2a malolactic starter cultures, and the accumulation of lactobacillic acid in the membrane of O. oeni SD-2a cells appears as an acid stress response mechanism, which might be related with the enhanced viability.     

酒酒球菌SD-2a原生质体制备条件研究

通过对预处理剂质量浓度、酶质量浓度、酶解时间、菌龄等影响因素的分析,以及渗透压稳定剂的筛选,对酒酒球菌SD-2a原生质体的制备条件进行了研究。结果表明,酒酒球菌SD-2a原生质体制备的最佳条件为:菌龄20 h,青霉素G钠质量浓度0.5μg/mL,酶质量浓度1mg/mL,酶解时间30 min,渗透压稳定剂采用SMM缓冲液,再生培养基采用添加0.7 mol/LKCl的ATB培养基,再生培养时采用双层培养基厌氧培养,可以保证较好的形成率和再生率。     

Genome-wide identification and characterization of the JAZ gene family and its expression patterns under various abiotic stresses in Sorghum bicolor

The jasmonate ZIM domain (JAZ) protein belongs to the TIFY ((TIF[F/Y]XG) domain protein) family, which is composed of several plant-specific proteins that play important roles in plant growth, development, and defense responses. However, the mechanism of the sorghum JAZ family in response to abiotic stress remains unclear. In the present study, a total of 17 JAZ genes were identified in sorghum using a Hidden Markov Model search. In addition, real-time quantification polymerase chain reaction (RT-qPCR) was used to analyze the gene expression patterns under abiotic stress. Based on phylogenetic tree analysis, the sorghum JAZ proteins were mainly divided into nine subfamilies. A promoter analysis revealed that the SbJAZ family contains diverse types of promoter cis-acting elements, indicating that JAZ proteins function in multiple pathways upon stress stimulation in plants. According to RT-qPCR, SbJAZ gene expression is tissue-specific. Additionally, under cold, hot, polyethylene glycol, jasmonic acid, abscisic acid, and gibberellin treatments, the expression patterns of SbJAZ genes were distinctly different, indicating that the expression of SbJAZ genes may be coordinated with different stresses. Furthermore, the overexpression of SbJAZ1 in Escherichia coli was found to promote the growth of recombinant cells under abiotic stresses, such as PEG 6000, NaCl, and 40°C treatments. Altogether, our findings help us to better understand the potential molecular mechanisms of the SbJAZ family in sorghum in response to abiotic stresses.     

用苹果酸通透酶基因的特异性引物进行酒酒球菌快速鉴定

以Oenococcus oeni苹果酸通透酶基因为目标基因,设计了1对特异性引物PmlepL/PmlepR进行酒酒球菌的快速鉴定研究。结果表明,直接以O.oeni的菌落为模板,通过PmlepL/PmlepR引物的PCR扩增,可得到苹果酸通透酶基因的特异性条带;用此特异性引物进行供试乳酸菌的PCR鉴定,所有O.oeni菌系均得到特异性条带,而供试的其他种类乳酸菌未扩增出目标带。引物PmlepL/PmlepR可用于O.oeni的快速PCR鉴定。     

mleA基因在酿酒酵母中的整合型表达

 【目的】进行中国自行筛选的专利菌种酒酒球菌 SD-2a（Oenococcus oeni SD-2a）的苹果酸－乳酸酶基因在酿酒酵母中的整合型表达,使葡萄酒生产过程中的酒精发酵和苹果酸－乳酸发酵（malolactic fermentation,MLF）同时进行。【方法】克隆Oenococcus oeni SD-2a的苹果酸－乳酸酶基因mleA,以PGK1强启动子和ADH1终止子为调控元件,以酵母整合型质粒YIp5为载体,构建重组表达质粒pYILmleA,并转化酿酒酵母（Saccharomyces cerevisiae）YS59,经筛选鉴定获得酵母转化子YS59/pYILmleA。进行转化子的营养缺陷型和交配型鉴定、菌落PCR鉴定、SDS-PAGE检测及斑点杂交检测,并对酵母转化子培养上清液进行L-苹果酸及L-乳酸含量的HPLC分析,检测目的基因的功能性表达。【结果】转化子的营养缺陷型和交配型鉴定、菌落PCR鉴定表明获得了阳性转化子;SDS-PAGE检测表明获得的转化子表达了目标蛋白,斑点杂交检测表明目的基因整合到受体菌中。模拟发酵表明mleA基因整合到受体菌中后进行了功能性表达,将培养基中的L-苹果酸转化成L-乳酸,使得培养液中的L-苹果酸含量极显著降低。转化子YS59/pYILmleA在添加5 648 mg?L-1 L-苹果酸和10%葡萄糖的SD/-Ura培养基中培养4 d,培养液上清中L-苹果酸的剩余含量与空载体转化子YS59/YIp5（对照）差异极显著,苹果酸的相对降低率为20.18%～20.85%。供试的转化子L-乳酸生成量为1 278～1 312 mg?L-1,对照未检出乳酸的生成。【结论】中国自主筛选的专利菌种O.oeni SD-2a的mleA基因的整合型表达质粒构建成功并在酿酒酵母中进行了功能性表达。     

植物热激蛋白响应非生物胁迫研究进展

非生物胁迫对农作物正常生长具有重要影响,非生物胁迫可改变细胞蛋白质构象,使非天然蛋白 质发生聚集,破坏细胞膜结构。热激蛋白（heat shock proteins,Hsps）负责蛋白质的折叠、组装、转运与降解, 并能在胁迫条件下协助蛋白质复性,通过重建正常的蛋白质构象从而恢复细胞稳态,参与其他应激反应机制, 在保护植物免受非生物胁迫方面起着重要作用。总结了各类 Hsps 在植物非生物胁迫响应中发挥的功能,阐述 Hsps 参与其他应激反应机制并发挥一定作用,对目前 Hsps 在研究中存在的问题进行讨论和展望,为作物分子育 种筛选抗逆基因提供理论依据。     

促生细菌挥发性有机物调控根部质膜H+-ATPase 活性提高植物耐碱胁迫能力

根际促生细菌的挥发性有机化合物（VOCs）可以促进植物生长并提高植物对盐、旱和病菌的抵抗力。分析了芽孢杆菌PDR1产生的VOCs对拟南芥耐碱胁迫能力的影响及其生理机制。在芽孢杆菌PDR1存在或不存在的条件下，对拟南芥进行培养；检测对照和碱胁迫条件下拟南芥根部的各种离子含量；用pH指示剂（溴甲酚紫）和pH计检测拟南芥的根际酸化能力；检测拟南芥根部质膜H⁺-ATPase活性。结果显示，芽孢杆菌PDR1的VOCs改善了同一空间中碱胁迫下拟南芥的根长和根部离子平衡；来自芽孢杆菌PDR1的VOCs增强了拟南芥根中质膜H⁺-ATPase的活性，并提高了拟南芥植物的根际酸化能力。研究结果将促进对芽孢杆菌调节拟南芥生长和抗逆性机制的理解，并为其在农业生产和生态保护中的广泛应用奠定基础。     

Identification of the DEAD-box RNA helicase family members in grapevine reveals that VviDEADRH25a confers tolerance to drought stress

Grapevine growing areas are increasingly affected by drought, which has greatly limited global wine production and quality. DEAD-box is one of the largest subfamilies of the RNA helicase family, and its members play key roles in the growth and development of plants and their stress responses. Previous studies have shown the potential of DEAD-box genes in the drought stress responses of Arabidopsis and tomato, rice, and other crop species. However, information about DEAD-box genes in grapevine remains limited. In this report, a total of 40 DEAD-box genes were identified in grapevine and their protein sequence characteristics and gene structures were analyzed. By comparing the expression profiles of VviDEADRHs in response to drought stress in different grapevine varieties, nine candidate genes (VviDEADRH10c, -13, -22, -25a, -25b, -33, -34, -36, and -39) were screened based on expression profiling data. Combined with qRT-PCR results, VviDEADRH25a was selected for functional verification. Heterologous overexpression of VviDEADRH25a in Arabidopsis showed the transgenic plants were more sensitive to drought stress than the control. Both electrolyte permeability and malondialdehyde content were significantly increased in transgenic plants, whereas the chlorophyll content and superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) enzyme activities were significantly decreased. Furthermore, VviDEADRH25a-overexpressing plants showed down-regulated expression levels of several drought stress-related marker genes, namely AtCOR15a, AtRD29A, AtERD15, and AtP5CS1, which indicated that they participated in the drought stress response. In summary, this study provides new insights into the structure, evolution, and participation of DEAD-box RNA helicase genes in the response to drought stress in grapevines.     

沙棘果酒苹果酸-乳酸发酵影响因素研究

以沙棘果为原料,利用酒酒球菌降酸生产全汁沙棘果酒,通过单因素正交试验确定酒精发酵的最佳条件为:pH值3.4,发酵温度25℃,接菌量8%,接种时间为酒精发酵后(顺序发酵),SO2浓度30 mg.L-1,发酵时间为8 d。苹果酸-乳酸发酵(MLF)结束后,沙棘果酒的总酸由原来的15.20 g.L-1降为9.83 g.L-1,苹果酸降解量5 422.07 mg.L-1、挥发酸增加量261 mg.L-1。在此工艺条件下酿制的沙棘果酒不仅使苹果酸大部分转化为乳酸,并且沙棘果酒的酸涩味减弱,口感得到很大的改善。     

Fatty Acids and Antimicrobial Properties of Red Table Wine

The article presents research findings on fatty acids and antibacterial properties of red wine, which is known for its unique physiological effect on the human body. The subjects of research were red table wines (the vintage of 2016) produced at the Derbent sparkling wine factory from grapes grown in Derbentskii district of the Dagestan Republic. Wines were produced from a Cabernet grape variety from the Saccharomyces cerevisiae Y-4270 (experiment) and Saccharomyces cerevisiae Derbent-19 (control) wine yeast strains. Fatty acid compositions using gas-liquid chromatography and the antibacterial properties against gram-positive bacteria with a standard agar diffusion technique were examined. A total of 28 fatty acids (C₁₀–C₂₂) were identified in all samples of wine. The experimental sample was noted for a reduced content (by 8.63%) of saturated fatty acids undesirable for living organisms as the factor of nutrition that increases levels of cholesterol and atherogenic lipoprotein. The total amount of unsaturated fatty acids was observed to increase by 18.67% due to the dominance of С_18:2, С_18:2ω-6, and С_24:1ω-9. The predominance of polyunsaturated fatty acids (double), monounsaturated (by 9.56%), and polyenoic fatty acids (by 12.09%), which contribute to the composition of wine flavor, was detected. The amount of ω-6 acids is 42.12% higher, primarily owing to linoleic C_18:2ω-6 (by 16.48%) and γ-Linolenic C_18:3ω-6 (almost by a factor of four) acids. A significant content of ω-3 acids (almost by a factor of 11) was revealed, specifically, linolenic C_18:3ω-3, eicosapentaenoic C_20:5ω-3, and docosahexaenoic C_22:6ω-3 acids, which improve lipid metabolism and have a positive effect on the immune system. In general, the total content of ω-9 acids was sufficiently high in both samples of wine due to the predominance of oleic C_18:1ω-9 acid. The experimental red table wine has been found to possess antibacterial properties against bacteria Shigella sonnei, Salmonella typhimurium, Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, Proteus mirabilis, and Staphylococcus saprophyticus, resulting from the constituent conditions of the wine, including polyphenolic and antioxidant compounds, which provide the product with improved biochemical and nutrient properties.     

Response of Osmotic Adjustment of Lactobacillus bulgaricus to NaCl Stress

Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of ...     

Genome-wide identification and characterization of the abiotic-stress-responsive lipoxygenase gene family in diploid woodland strawberry (Fragaria vesca)

Lipoxygenase (LOXs) is a kind of dioxygenase without heme and iron, which plays an important role in the development and adaptation of many plants to the environment. However, the study of strawberry LOX gene family has not been reported. In this study, 14 LOX genes were identified from the diploid woodland strawberry genome. The phylogenetic tree divides the FvLOX gene into two subfamilies: 9-LOX and 13-LOX. Gene duplication event analysis showed that whole-genome duplication (WGD)/segmental duplication and dispersed duplication effectively promoted the expansion of strawberry LOX family. QRT-PCR analysis showed that FvLOX genes were expressed in different tissues. Expression profile analysis showed that FvLOX1 and FvLOX8 were up-regulated under low temperature stress, FvLOX3 and FvLOX7 were up-regulated under drought stress, FvLOX6 and FvLOX9 were up-regulated under salt stress, FvLOX2, FvLOX3 and FvLOX6 were up-regulated under salicylic acid (SA) treatment, FvLOX3, FvLOX11 and FvLOX14 were up-regulated under methyl jasmonate (MeJA) treatment, FvLOX4 and FvLOX14 were up-regulated under abscisic acid (ABA) treatment. Promoter analysis showed that FvLOX genes were involved in plant growth and development and stress response. We analyzed and identified the whole genome of strawberry FvLOX family and characterized a variety of FvLOX candidate genes involved in abiotic stress response. This study laid a theoretical and empirical foundation for the response mechanism of strawberry to abiotic stress.     

碱蓬属植物耐盐机理研究进展

碱蓬属(Suaeda)植物是一类典型的真盐生植物,属于重要的盐生植物资源,全球广泛分布.人们已经对20种碱蓬属植物进行了观察和盐胁迫实验,研究了不同器官或组织的生理生化特征及其对盐胁迫的反应,并基于这些研究分析了盐胁迫的应答机制.叶片肉质化、细胞内离子区域化、渗透调节物质增加和抗氧化系统能力增强是碱蓬属植物响应和适应盐胁迫的重要方式和途径.但迄今为止的研究工作尚有一定的局限性,主要包括:研究工作主要集中在植物地上部分,而对植物地下部分的研究较少;多是少数生物学指标或生理学现象的单独观察,而缺乏对生理代谢过程的整体和综合分析;针对某种碱蓬的独立分析较多,而与近缘种的比较研究较少;植物对中性盐胁迫的反应研究较多,而对碱性盐的研究较少.为进一步系统阐明碱蓬属植物的耐盐机制,今后的工作应注重碱蓬属植物响应和适应盐胁迫的信号网络和调控机制研究,基于系统生物学研究思路,采用现代组学技术探索该属植物响应盐胁迫的由复杂信号网络调控的特殊生理特征和特异代谢途径.     

Genome-wide identification and analysis of the regulation wheat DnaJ family genes following wheat yellow mosaic virus infection

The co-chaperone DnaJ plays an important role in protein folding and regulation of various physiological activities, and participates in several pathological processes. DnaJ has been extensively studied in many species including humans, drosophila, mushrooms, tomatoes, and Arabidopsis. However, few studies have examined the role of DnaJ in wheat (Triticum aestivum), and the interaction mechanism between TaDnaJs and plant viruses. Here, we identified 236 TaDnaJs and performed a comprehensive genome-wide analysis of conserved domains, gene structure and protein motifs, chromosomal positions and duplication relationships, and cis-acting elements. We grouped these TaDnaJs according to their domains, and randomly selected six genes from the groups for tissue-specific analysis, and expression profiles analysis under hormone stress, and 17 genes for plant virus infection stress. In qRT-PCR, we found that among the 17 TaDnaJ genes tested, 16 genes were up-regulated after wheat yellow mosaic virus (WYMV) infection, indicating that the TaDnaJ family is involved in plant defense response. Subsequent yeast two-hybrid assays verified the WYMV NIa, NIb and 7KD proteins interacted with TaDJC (TraesCS7A02G506000), which had the most significant changes in gene expression levels after WYMV infection. Insights into the molecular mechanisms of TaDnaJ-mediated stress tolerance and sensitivity could inform different strategies designed to improve crop resistance to abiotic and biotic stress. This study provides a basis for future investigation of the TaDnaJ family and plant defense mechanisms.     

水分胁迫对水稻结实期活性氧产生和保护系统的影响

 【目的】探索不同抗旱品种在结实期水分胁迫条件下叶片活性氧对水稻膜脂的伤害和清除机制。【方法】选用抗旱性不同的3个杂交水稻品种，在干旱棚内分别在正常供水和水分胁迫条件下，研究水稻结实期超氧阴离子自由基（O2-）、双氧水（H2O2）、丙二醛（MDA）、还原型谷胱甘肽（GSH）、抗坏血酸（AsA）及保护性酶活性等生理性状变化。【结果】结实期随土壤水分胁迫加剧和时间延长，细胞膜脂过氧化加重，抗旱性弱的品种膜脂过氧化更为严重；O2- 和H2O2积累迅速，抗旱性弱的品种比抗旱性强的品种积累速度快、幅度大；GSH、AsA、叶绿素含量和叶片相对含水量下降，且表现为，抗旱性弱的品种降速快、幅度大。抽穗后0～14 d随胁迫时间的延长叶片内超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）3种酶活性升高，随后下降。【结论】抗旱性强的品种具有较强的抗氧化能力；O2-积累速率、H2O2含量、叶片MDA含量、GSH含量、AsA含量及保护性酶活性的变化幅度与品种的抗旱性密切相关。     

番茄USP1响应干旱和高温胁迫的研究

DDB1作为CUL4泛素连接酶的核心组件参与细胞内许多重要的生命活动。前期研究发现番茄CUL4-DDB1复合物（CRL4）调节植物细胞的非生物胁迫应答。为进一步阐明DDB1在植物抗逆中的调控机制和生理功能,通过酵母双杂交筛选,发现普遍应激蛋白USP1与DDB1存在相互作用, USPs家族蛋白参与提高生物体对逆境胁迫的耐受;进一步研究发现USP1定位于细胞质中,且其基因表达受到多种胁迫条件诱导。此外泛素化实验揭示USP1可以被泛素化修饰降解,上调USP1表达导致植株对干旱和高温抗性的增强,表明USP1可能正调控番茄植株对逆境下胁迫的应答,且它的作用受CUL4-DDB1泛素连接酶的靶向降解调控。结果不仅揭示新的植物抗逆机理,而且为植物抗逆分子育种提供新的基因资源和技术途径。