SCFAs对奶牛瘤胃上皮细胞Ca2+信号通路相关基因表达的影响

为探究短链脂肪酸(SCFAs)对奶牛瘤胃上皮细胞(BRECs)Ca~(2+)信号通路相关基因表达的影响,试验分为3个处理组,分别为野生型BRECs组,含20mmol/L SCFAs BRECs组,含20mmol/L SCFAs且通过CRISPR/Cas 9系统敲除GPR41基因的BRECs组,每个处理组3个重复,每组细胞均培养24h后,收集细胞提取总RNA,通过qRT-PCR对Ca~(2+)信号通路相关基因的mRNA表达量和细胞内Ca~(2+)浓度进行测定。结果表明,与野生型BRECs相比,添加20mmol/L SCFAs可极显著增加PLCB2的mRNA表达量(P0.01),显著增加IP3R1的mRNA表达量(P0.05),对PLCE1、PLCL1、PKCB和PKCG的mRNA表达量无显著差异(P0.05),可增加细胞内Ca~(2+)浓度但无显著差异(P0.05);敲除SCFAs的受体GPR41后,添加20 mmol/L SCFAs可显著降低IP3R1的mRNA表达量(P0.05),极显著上调PLCE1和PLCB2的mRNA表达量(P0.01),但对PLCL1、PKCB和PKCG的mRNA表达量无显著影响(P0.05),细胞内Ca~(2+)浓度有降低趋势但无显著差异(P0.05)。综上,SCFAs可以通过激活其受体GPR41来调控BRECs内Ca~(2+)信号通路中相关基因的表达和细胞内Ca~(2+)的释放。     

超高效液相色谱—串联质谱法检测鸡血液样品中喹诺酮类药物残留

旨在建立鸡血液样品中多种喹诺酮类药物残留的超高效液相色谱—串联质谱方法。样品经乙腈提取,经Waters Acquity UPLC BEH C₁₈色谱柱分离,以甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱,电喷雾正离子（ESI⁺）模式电离,MRM扫描模式检测。经方法学验证,该方法的线性关系、回收率、精密度均符合要求。应用超高效液相色谱—串联质谱法建立了鸡血液样品中多种喹诺酮类药物同时检测的方法,实现了动物血液样品中12种喹诺酮类药物同时定性、定量分析。     

Exogenous application of allelopathic water extracts helps improving tolerance against terminal heat and drought stresses in bread wheat (Triticum aestivum L. Em. Thell.)

The allelopathic water extracts (AWEs) may help improve the tolerance of crop plants against abiotic stresses owing to the presence of the secondary metabolites (i.e., allelochemicals). We conducted four independent experiments to evaluate the influence of exogenous application of AWEs (applied through seed priming or foliage spray) in improving the terminal heat and drought tolerance in bread wheat. In all the experiments, two wheat cultivars, viz. Mairaj‐2008 (drought and heat tolerant) and Faisalabad‐2008 (drought and heat sensitive), were raised in pots. Both wheat cultivars were raised under ambient conditions in the wire house till leaf boot stage (booting) by maintaining the pots at 75% water‐holding capacity (WHC). Then, managed drought and heat stresses were imposed by maintaining the pots at 35% WHC, or shifting the pots inside the glass canopies (at 75% WHC), at booting, anthesis and the grain filling stages. Drought stress reduced the grain yield of wheat by 39%–49%. Foliar application of AWEs improved the grain yield of wheat by 26%–31%, while seed priming with AWEs improved the grain yield by 18%–26%, respectively, than drought stress. Terminal heat stress reduced the grain yield of wheat by 38%. Seed priming with AWEs improved the grain yield by 21%–27%; while foliar application of AWEs improved the grain yield by 25%–29% than the heat stress treatment. In conclusion, the exogenous application of AWEs improved the stay green, accumulation of proline, soluble phenolics and glycine betaine, which helped to stabilize the biological membranes and improved the tolerance against terminal drought and heat stresses.     

Mapping the spatial distribution of shade provision of street trees in Boston using Google Street View panoramas

Street trees provide shade and increase human thermal comfort during hot summer. In this study, we investigated the spatial distribution of shade provision of street trees in Boston, Massachusetts. The sky view factor (SVF), which influences the solar radiation to the ground and affects human thermal comfort, was used to indicate the contribution of street trees on shade provision. Google Street View (GSV) panoramas were used to calculate the photographic method based SVF (SVF_P), with the consideration of all kinds of obstructions within street canyons. A building height model was used to calculate the simulation based SVF (SVFs), with consideration of obstruction of building blocks only. Considering the fact that street trees and building blocks are the two major obstructions of radiation within street canyons, therefore, the difference between the two SVF estimation results can be considered as the shade provision of street trees. The results show that street trees help to decrease the SVF by 24.61% in Boston, Massachusetts. The shading level varies spatially in the study area. Generally, the southwestern area has much higher shading level than the north and the east. We further explored the shading variation among different socioeconomic groups in the study area. Result shows that Hispanics tend to live in neighborhoods with lower shading level. This study can help to provide a reference for future urban greening projects for global climate change adaption.     

Relationships between body size and secondary sexual characters,and sperm characters in male Dolly Varden char (Salvelinus malma)

In Salmonidae, subordinate males are exposed to higher risks of sperm competition than dominant males and thus are expected to improve the sperm characteristics (sperm concentrations, sperm velocity and sperm longevity). In this study, we investigated the relationships between body size and secondary sexual characters (breeding colour, hump height and snout length), and sperm characteristics of one‐year‐old (newly matured) Dolly Varden char. Small males displayed higher sperm concentrations than large males. Moreover, males with dull breeding colours, but not with lesser snout length and hump height, displayed an increased sperm velocity compared to males with bright colours, suggesting a trade‐off between sperm quantity and the investment in breeding colour. In addition, sperm longevity decreased as sperm swimming velocity increased. These findings indicate that small males with dull breeding colours improve the quantity and quality of their sperm to a great extent to enhance their chances of reproductive success.     

大豆质核互作雄性不育系NJCMS1A与其保持系NJCMS1B的生理生化特性比较分析

以大豆质核互作雄性不育系NJCMS1A及其保持系NJCMS1B的花芽为试验材料,利用试剂盒法和紫外分光光度计测定分析了糖分含量(可溶性糖和淀粉)和总ATPase、蔗糖磷酸合成酶(SPS)、磷酸烯醇式丙酮酸羧激酶(PEPCK)、抗坏血酸氧化酶(AO)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)以及过氧化物酶(POD)等酶活性的变化情况。结果表明:相较于保持系NJCMS1B,总ATPase、PEPCK、AO和CAT活性在不育系NJCMS1A中显著下降;糖分含量、SPS和SOD活性在不育系NJCMS1A中下降水平不显著;POD活性在不育系NJCMS1A中显著上升。根据结果分析推测,与能量代谢或胁迫响应等相关的物质或酶活性在不育系NJCMS1A中的亏损现象可能是NJCMS1A花粉败育的主要原因。     

不同施肥处理对枳及柠檬容器苗生长的影响

研究9个不同施肥处理对枳及柠檬容器苗生长的影响。结果表明:不同施肥处理对枳容器苗的苗高、地径、分枝高度及嫁接后柠檬苗的发芽率、株高、茎粗、分枝数及生物量都存在显著差异;不同施肥处理对枳及柠檬容器苗综合表现最好的为T4(撒施柠檬专用肥1.6 g)处理,其次是T2(撒施尿素0.6 g)、T3(撒施柠檬专用肥0.8 g)处理,表现最差的是T8(浇施5%柠檬专用肥)和T7(浇施3%柠檬专用肥)处理。在一定施肥浓度范围内,施肥对嫁接后柠檬容器苗的生物量积累有明显促进作用。柠檬容器苗培育时建议采用在基质中撒施柠檬专用肥1.6 g。     

青霉菌发酵液对大豆幼苗生长及生理特性的影响

采用室内生理检测及生物化学方法,研究了青霉菌发酵液对大豆幼苗生长及生理特性的影响。结果表明:用一定浓度的青霉菌发酵液对大豆浸种和茎叶处理,大豆幼苗的生长呈明显上升趋势,处理后大豆的株高、根长、株鲜重和根鲜重均明显得到了提高,且生长状态好于对照,不同浓度处理间具有明显差异,在发酵液浓度为5 g·L-1时,效果最佳。尤其是对根鲜重的影响,促进率最高可达56.21%,同时增强了幼苗根系活力,最大可以提高57.82%,浸种和茎叶处理后,分别提高了叶绿素含量41.25%和15.40%;超氧化物歧化酶活性12.20%和11.70%;过氧化物酶31.33%和29.95%;过氧化氢酶活性42.8%和20.0%,这为发酵液在大豆田推广应用、提高大豆产量提供了重要理论依据。     

Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.