水稻OsZ314基因克隆及转录激活验证

穗是水稻(Oryza sativa L.)重要的生殖器官,其生长发育直接影响水稻的产量和品质。前期研究中,我们对水稻生殖生长时期穗发育各阶段的转录组、蛋白组数据进行联合分析,筛选到一个MYB基因家族的转录因子OsZ314基因。生物学信息分析表明,该基因位于1号染色体上,拥有典型的R2R3-MYB型转录因子结构域,且在水稻幼穗时期表达量最高;亚细胞定位结果显示,OsZ314基因定位于细胞核中;转录激活试验表明,OsZ314基因具有转录激活功能。本研究为深入探索OsZ314基因在水稻穗发育时期的分子生物学功能奠定了良好的基础。     

马铃薯红外干燥特性研究

以马铃薯为原料,研究其红外干燥特性及数学模型。通过试验收集了不同切片厚度和干燥温度下马铃薯水分比(MR)随干燥时间(t)的变化数据,得到了马铃薯的干燥曲线,并计算了干燥过程中的有效水分扩散系数(Deff)和干燥活化能(Ea)。结果表明,干燥温度(T)与切片厚度(L)对马铃薯红外干燥特性有较大影响,干燥温度越高,切片厚度越薄,马铃薯的干燥速率(DR)越快,干燥时间越短;同时,通过拟合计算发现,在10种干燥模型中Modified Henderson and Pabis的预测值与实测值比较吻合,能够更好地反映干燥过程。在试验条件下,Deff在0.238 4×10-10~12.557 3×10-10m~2·s-1之间,且随着干燥温度和切片厚度的增加而增大。1、3、5、7 mm厚的马铃薯片红外干燥活化能分别为34.386 0、31.041 8、28.783 2、30.060 1 k J/mol。     

Hygroscopic salts support the stomatal penetration of glyphosate and influence its biological efficacy

The objective of this study was to better understand the role of chaotropic and kosmotropic salts in stomatal uptake, a process that occurs in parallel with cuticular penetration and affects the bioefficacy of glyphosate. In Trial 1, salt solutions of kosmotropic (NH₄)₂SO₄ and chaotropic NaClO₃, with or without the organosilicone surfactant, Break‐Thru® S233 (BT), and with or without glyphosate, were prepared. In Trial 2, sodium salts with a kosmotropic‐to‐chaotropic nature (Na₂SO₄, NaCl, NaNO₃ or NaClO₃) and BT were prepared with or without glyphosate. At very high concentrations, the salts of a kosmotropic nature induced a slight decrease in the surface tension, whereas those of a chaotropic nature triggered a significant decrease in the surface tension. Solution droplets were deposited onto the leaves of Viola arvensis and Chenopodium album. The dried deposits were analyzed with an environmental scanning electron microscope. The salts formed structures linking the exterior to the interior of the stomata in the crystalline ([NH₄]₂SO₄) or amorphous (NaClO₃) form. However, the low surface tension alone did not appear to be the unique driving force for stomatal uptake. With glyphosate, amorphous globular structures of glyphosate salt were formed in the Na₂SO₄ (kosmotropic) solution. Differently, the salts of a rather chaotropic nature (NaNO₃ or NaClO₃) formed a colloidal matrix. In general, salt residues were observed over the periclinal cell walls and inside the stomatal chamber. Neither (NH₄)₂SO₄ nor Na₂SO₄ had a significant impact on glyphosate bioefficacy. However, the chaotropic salt, NaNO₃, enhanced the bioefficacy of glyphosate the most, with a performance that was comparable to that of the solution glyphosate + organosilicone surfactant.     

ZnCl2法制备的甘蔗渣活性炭对实验室有机废液的吸附特性

[目的]研究在不同条件下制得的海南甘蔗渣活性炭对有机实验室废水的处理能力。[方法]以ZnCl_2为活化剂,采用L16(43)正交试验法,研究以甘蔗渣为原材料制备活性炭的工艺,及其对实验室有机废液的吸附特性。[结果]影响活化效果的因素主次顺序为ZnCl_2溶液质量浓度、料液比、活化时间。在500℃时最佳活化的工艺条件为活化剂ZnCl_2溶液质量浓度180 g/L、料液比1.5、活化时间60 min,在该条件下制得的甘蔗渣活性炭对有机实验室废液的处理效果最好,活性炭粒径在100~120目为宜。[结论]该研究可为实验室有机废液处理提供科学依据。     

稳定表达山羊SLAM受体的BHK-21细胞系的建立及应用

信号淋巴激活分子(SLAM)又称为CD150,是小反刍兽疫病毒(PPRV)和犬瘟热病毒(CDV)等麻疹病毒属病毒感染淋巴细胞的主要受体,在病毒侵入细胞中发挥重要作用。为建立稳定表达山羊SLAM(g SLAM)的真核细胞系,本研究将人工合成的g SLAM基因克隆至真核表达质粒p IRESpuro3中,并在该基因的3'端引入Flag标签序列作为分子标记,构建了重组质粒p IRES3-g SLAM。将该重组质粒转染BHK-21细胞,经嘌呤霉素加压筛选及采用表达绿色荧光蛋白(GFP)的重组PPRV病毒(r PPRV/GFP)感染鉴定后,筛选到稳定表达g SLAM基因的细胞系。r PPRV/GFP感染和western blot鉴定表明,无论是否有嘌呤霉素压力的存在,该细胞系在传代至第20代,仍能稳定表达g SLAM蛋白。由于g SLAM氨基酸序列与犬的同源性较高,以表达GFP重组CDV强毒株(r CDV/GFP)感染该细胞系,病毒可以感染且能形成明显的细胞病变,表明该细胞系可用于CDV强毒分离和致弱机制等相关研究。     

No effect of exogenous melatonin on development of cryopreserved metaphase II oocytes in mouse

Background

This study was conducted to investigate effect of exogenous melatonin on the development of mouse mature oocytes after cryopreservation.

Results

First, mouse metaphase II (MII) oocytes were vitrified in the open-pulled straws (OPS). After warming, they were cultured for 1 h in M₂ medium containing melatonin at different concentrations (0, 10⁻⁹, 10⁻⁷, 10⁻⁵, 10⁻³ mol/L). Then the oocytes were used to detect reactive oxygen species (ROS) and glutathione (GSH) levels (fluorescence microscopy), and the developmental potential after parthenogenetic activation. The experimental results showed that the ROS level and cleavage rate in 10⁻³ mol/L melatonin group was significantly lower than that in melatonin-free group (control). The GSH levels and blastocyst rates in all melatonin-treated groups were similar to that in control. Based on the above results, we detected the expression of gene Hsp90aa1, Hsf1, Hspa1b, Nrf2 and Bcl-x1 with qRT-PCR in oocytes treated with 10⁻⁷, or 10⁻³ mol/L melatonin and untreated control. After warming and culture for 1 h, the oocytes showed higher Hsp90aa1 expression in 10⁻⁷ mol/L melatonin-treated group than in the control (P < 0.05); the Hsf1, Hsp90aa1 and Bcl-x1 expression were significantly decreased in 10⁻³ mol/L melatonin-treated group when compared to the control. Based on the above results and previous research, we detected the development of vitrified-warmed oocytes treated with either 10⁻⁷ or 0 mol/L melatonin by in vitro fertilization. No difference was observed between them.

Conclusions

Our results indicate that the supplementation of melatonin (10⁻⁹ to 10⁻³ mol/L) in culture medium and incubation for 1 h did not improve the subsequent developmental potential of vitrified-warmed mouse MII oocytes, even if there were alteration in gene expression.     

Acidulated activation of phosphate rock enhances release,lateral transport and uptake of phosphorus and trace metals upon direct-soil application

Phosphate rock (PR) was activated via acidulation with HCl, EDTA, and oxalic acid to enhance its reactivity. The release, lateral transport, and uptake of phosphorus (P) along with trace metals from pristine and activated PRs were investigated in a soil micro-block system over a period of 27 days, using wheat (Triticum aestivum L.) plants. Significantly (p < 0.05) higher amounts of available soil P, Fe, Mn, and Zn were released from all the PRs after application to soil within first 9 days of seedling transplantation, while the release of other trace metals (Cd, Co, Cr, Cu, Ni, and Pb) was minimal (<1.2 mg kg^?1). On cumulative basis, APR-O (oxalic acid activated PR) was the most efficient amendment releasing 164% more available P, followed by APR-E (EDTA activated PR) releasing 130% more available P, compared to the pristine PR. Similar results were also observed in the release of available Fe, Mn, Zn, and other trace metals. The highest diffusive mass fluxes for available P, Mn, Fe, and Zn in soil were observed after 3 days of seedling transplantation, which reduced subsequently. The uptake of P, Fe, Mn, and Zn by wheat plants was increased by 394%, 715%, 92%, and 91%, respectively, in APR-O application compared to the pristine PR, while it was increased by 280%, 188%, 16%, and 27%, respectively, in APR-E application compared to the pristine PR. Subsequently, APR-O and APR-E amendments resulted in enhanced shoot lengths, root lengths, shoot dry matter, and root dry matter contents of wheat plants. Hence, it was concluded that activation of PR with oxalic acid and EDTA prior to direct soil application may enhance the reactivity of PR and could serve as a cost-effect fertilization strategy for higher wheat crop production.     

Bromine Accumulation in Some Crops and Grasses as Determined by Neutron Activation Analysis

Till now information on bromine (Br) in the environment is still incomplete. The purposes of this research were the following: to study accumulation of Br in plants grown under different environmental conditions and to assess the factors controlling Br uptake by different plant species when the plants grow in soil uncontaminated with Br. For the determination of Br and other elements, neutron activation analysis was used. This method allows for determining a wide range of elements in various samples with high sensitivity and accuracy. Model tests and greenhouse experiments demonstrated different abilities of plants to uptake Br from various media and transfer it from roots to upper plant parts. It was shown that the main source of Br for a plant was soil. As a result of the plant growth concentration of Br in the rhizosphere soil decreased. The characteristics of soil have a pronounced effect on the Br uptake by plants.     

不同化学激活方法及卵丘细胞层数对牛体外成熟卵母细胞孤雌发育的影响

为探索适宜的牛体外成熟卵母细胞孤雌激活方式,提高核移植效率及研究胚胎孤雌发育.研究比较了不同浓度的乙醇(EH)、离子霉素( ionomycin)、钙离子载体A23187与蛋白激酶抑制剂6-二甲氨基嘌呤(6-DMAP)、细胞松驰素(cytochalasin B,CCB)对牛卵母细胞激活发育的影响,并在相同条件下,比较了不同卵丘细胞层数对卵母细胞激活后胚胎发育能力的影响.结果表明:(1)5 μmol· L-1 Ionomycin,10 μmol·L-1A23187,7% EH分别联合2 mmol· L-1 6-DMAP,CCB均可以有效地激活牛孤雌胚,其中以lonomycin+6-DMAP+CCB组囊胚发育率极显著高于其他各组(P＜0.01),并且激活液中CCB的存在对牛孤雌胚胎的发育有利；(2)卵母细胞包被的卵丘细胞层数不同对卵母细胞成熟激活有显著的影响,卵丘细胞层数3～5层和多于6层的卵丘—卵母细胞复合体(COCs)孤雌激活的分裂率和囊胚率分别为69.09%,31.58%和75.14%,38.85%,这2组之间差异不显著(P＞0.05),但其显著高于1～2层组与混合组(P＜0.05),因此,这2组细胞是最佳的试验研究材料.