NaCl胁迫对番茄叶片光合特性及蔗糖代谢的影响

为了从碳水化合物生产及代谢的角度分析盐胁迫影响番茄产量和果实品质的原因,以番茄品种‘辽园多丽’为试材,研究不同浓度的NaCl胁迫处理对番茄光合特性及叶片中糖代谢的影响。结果表明:盐胁迫导致番茄叶片的净光合速率下降,NaCl浓度越大降低得越多;盐胁迫降低了番茄叶片的气孔导度、胞间CO2浓度和蒸腾速率,降低了番茄叶片的叶绿素a、b和总叶绿素含量,这种降低与NaCl浓度正相关。NaCl胁迫导致番茄叶片中果糖和葡萄糖大量积累,NaCl浓度越高积累得越多;NaCl胁迫降低了番茄叶片中的蔗糖和淀粉含量;NaCl胁迫后,番茄叶片中的转化酶活性以及蔗糖合成酶活性均有所提高,而且随着盐浓度增加而增大。说明NaCl胁迫破坏了番茄叶片的光合机能,降低了光合作用效率,而且盐浓度越大降低得越多;NaCl改变了番茄叶片中的糖代谢方向,显著增加了淀粉和蔗糖的分解,提高了叶片中的果糖和葡萄糖含量,而且这种影响随着盐浓度增加而增大。     

Effect of miRNA-33 on ABCA1/ABCG1 expression in RAW264.7 macrophage-derived foam cells after Hcy treatment

AIM:To study whether homocysteine (Hcy) inhibits the expression of ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) by microRNA-33 (miRNA-33) signaling, and reduces the efficiency of reverse cholesterol transport (RCT).METHODS:RAW264.7 macrophages were induced by oxidized low-density lipoprotein (ox-LDL) to establish foam cell model. Oil red O staining was used to determine whether the model was established successfully. miRNA-33 mimics and miRNA-33 inhibitor were transfected into the cells by Lipofectamine 2000, and the cells were exposed to Hcy at concentration of 5 mmol/L for 24 h. The intracellular lipid droplets were observed by Oil red O staining. The expression of ABCA1 and ABCG1 at mRNA and protein levels was determined by real-time PCR and Western blot. The cellular cholesterol content was analyzed by HPLC, and effluent rate of cholesterol was detected by the method of liquid scintillation counting.RESULTS:Compared with blank control group, the lipid content in miRNA-33 mimics group was increased, and the expression of ABCA1 and ABCG1 at mRNA and protein levels was decreased (P<0.05). The intracellular cholesterol content was increased gradually (P<0.05), and the cellular cholesterol efflux rate was gradually decreased (P<0.05) in miRNA-33 mimics group. Compared with blank control group, the testing results in miRNA-33 inhibitor group were the opposition of those in miRNA-33 mimics group (P<0.05). No diffe-rence of the above indexes among blank control group, miRNA-33 mimics-NC group and miRNA-33 inhibitor-NC group was observed.CONCLUSION:Hcy inhibits the mRNA and protein expression of ABCA1 and ABCG1 through miRNA-33 signaling, and reduces the efficiency of RCT in RAW264.7 macrophage-derived foam cells.     

荒漠草原产流产沙过程及养分运移特征

[目的] 荒漠草原夏季降雨强度大且集中性强,水力侵蚀危害严重,明确荒漠草原区产流产沙过程及养分运移规律对该地区开展水土保持工作有重要意义。[方法] 试验基于天然降雨观测和人工模拟降雨的方法,研究荒漠草原区产流产沙过程及养分运移规律,并通过对植被进行不同处理研究植被对产流产沙的影响。[结果] (1)不同植被处理方式的水土保持效果不同。3种不同处理方式中天然草地的水土保持效果最好,减流率与减沙率分别为11.37%和49.67%。(2)产流产沙过程改变地表土壤物质组成,使地表土壤粗粒化,还对土壤养分产生影响。降雨后砂粒含量增加5.97%~15.71%,土壤速效N、P及有机质分别减少40.84%,27.08%,33.49%。(3)坡面产流产沙量随坡度和降雨强度的增加而增加,幂函数能较好地拟合降雨历时与产流量和产沙量的关系。随降雨强度增加,坡度为5°~25°的峰值产流量平均增加6.70 L;降雨强度0.6~2.0 mm/L时,产沙量增长速度加快的拐点出现在坡度15°~20°。[结论] 研究结果可为荒漠草原区水土流失的综合防治提供理论参考,有助于改善荒漠草原区生态环境,有利于该地区开展水土保持工作。     

单燃料燃气汽车发动机空燃比控制器设计

通过对单燃料燃气汽车发动机空燃比控制系统进行分析和研究,自行设计出了PI控制器,并且进行了仿真与实验研究。通过对燃气供给量的调整,保证发动机获得最佳性能,将空燃比精确地控制在理论值附近,在环境、温度发生变化和长期使用的情况下,仍能保证控制系统具有良好的性能。     

减氮配施有机肥对滴灌春小麦花后同化物转运和籽粒灌浆特性的影响

[目的]研究减氮条件下新疆滴灌小麦高产高效的调控途径,分析滴灌春小麦花后同化物转运和籽粒灌浆特性的调控效应,为新疆滴灌春小麦的高产优质栽培提供科学依据.[方法]设置不同减氮配施有机肥处理,采用裂区设计,氮素为主区,品种为副区;于2019年在田间滴灌条件下设置7种减氮配施有机肥水平(NCK、N5、N10、N15、N20、...     

OVER- EXPRESSION OF AN AUX1 HOMOLOG TRIGGERS OVARY INITIATION IN VITRO OF POPULUS TOMENTOSA CARR.

INTRODUCTIONPolar transport is one key feature of auxin action was believed as a positional signal plays a wide arrange ofroles in plantgrowth and development,such as the gravity response[1],the initiation of lateral roots[2],positiondetermination of leaf primordial[3,4],differentiation of flower primordial[5],the axis formation in developingembryos[6~8],the patterned differentiation of vascular tissues[9~11].Polar auxin transport(PAT)system contributes indole-3-acetic acid(IAA)thorough …     

干巴菌菌丝营养生理特性的初步研究

本文报道了不同碳源、氮源、微量元素及维生素培养基对干巴菌菌丝生长的影响。试验表明,干巴菌菌丝利用最好的的碳源是葡萄糖,其次是蔗糖。利用最好的氮源是硝酸钙,其次是硝酸铵和硫酸铵,对蛋白胨和尿素的利用效果差。缺少碳源或氮源时,菌丝生长细弱、稀少,不形成原基。微量元素和维生素均对干巴菌菌丝生长有促进作用,其中以锰、铜和维生素Ｂ２的作用尤为突出。     

土壤溶质运移参数估计图解方法

基于土壤中溶质运移的对流 弥散方程 (CDE)提出了溶质运移参数估计的图解方法。根据土柱溶质运移“穿透曲线”(BTC)数据计算通量浓度随时间变化 (dc/dt)。应用绘图软件 ,例如MicrosoftExcel,绘制出t1 5dc/dt和dc/dt相对于时间的变化曲线。这两条曲线都是单峰曲线 ,并被用于估计CDE中延迟因子(R)和弥散系数 (D0 )。设计算例和穿透实验数据被用于校正图解法估计参数的精度和稳定性。参数估计的稳定性由估计参数对它们平均值的标准差评价 ;参数的估计精度与CXTFIT法和等斜率法比较。结果表明图解法具有较高的精度和较好的稳定性 ,特别是对于运移参数R的估值。图解法是一个确定性方法 ,它具备确定性方法中估计参数唯一性特点 ,克服了统计方法中需要给定参数初值的缺点。因此 ,这个方法是土壤溶质运移参数估计的可选方法之一。     

2003和2004年春季台北大气悬浮物中的水溶性离子(英文)

IntroductionTheoccurrenceofAsianduststorms(ADS)iscommonduringthemonthsoflatewinterandspringinEastAsia.Underfavorablesynopticconditions,significantamountsoftheAsiandustmaybetransportedtoTaiwan(Chen&Chen1987).Inrecentyears,ADSoverTaiwanreceivedsubstantialattentionbecauseoftheirimpactontheairquality.Besideshigherconcentrationsofmineralelements,highlevelsofanthropogenicspeciessuchassulfateandnitratehavebeenobservedintheoutflowfromtheAsiancontinent(Clarkeetal.2001).Thus,inthiswork,theinfluen…     

基于三维点云的运输车粮箱动态均匀装载方法研究

为了解决联合收获机-运输车协同作业时,运输车粮箱装载不均匀,导致粮箱装载利用率低的问题,提出了一种基于三维点云的动态均匀装载方法。该方法利用相机获取运输车粮箱内装载物的三维点云作为状态反馈信息,建立装载均匀性评估方式,以最均匀装载状态为目标,通过实时调整卸料装载点位置,使粮箱保持在均匀的装载状态。针对装载物相互遮挡对相机形成视觉盲区的问题,通过建立装载物的堆体模型和相机的遮挡模型,以最小期望误差为目标对盲区内装载物高度进行估计,并据此进行点云填充,从而得到能完整反映粮箱装载状态的三维点云。在搭建平台进行的实验中,对粮箱装载过程中可能出现的轻载、中载和重载3种装载状态进行测量,并对盲区点云位置进行估计,其盲区估计的平均误差低于5 cm。仿真结果表明,动态均匀装载方法能在有限装载周期内,将粮箱从任意的初始装载状态装载为均匀状态。单次装载量的平均高度增量为2 cm、粮箱的初始装载状态为空载时,装载物的最大高度方差为1 cm²。单因素仿真结果表明,稳定状态下的装载物高度方差与单次装载量正相关。