简介:Theannualseriesofδ13CweremeasuredintreeringsofthreeCryptomeriafortuneidisks(CF-1,CF-2,andCF-3)collectedfromWestTianmuMountain,ZhejiangProvince,China,accordingtocross-datingtreeringages.Therewasnoobviousdecreasingtrendoftheδ13CannualtimeseriesofCF-2before1835.However,from1835to1982thethreetreeringδ13Cannualseriesexhibitedsimilardecreasingtrendsthatweresignificantly(P≤0.001)correlated.Thedistributioncharacteristicsofascatterdiagrambetweenestimatedδ13CseriesofCF-2frommodelingandtheatmosphericCO2concentrationextractedfromtheLawDomeicecorefrom1840to1978wereanalyzedandacurvilinearregressionequationforreconstructingatmosphericCO2concentrationwasestablishedwithR2=0.98.Also,atestofindependentsamplesindicatedthatbetween1685and1839thereconstructedatmosphericCO2concentrationusingtheδ13CseriesofCF-2hadacloserelationshipwiththeLawDomeandSipleicecores,withastandarddeviationof1.98.ThegeneralincreasingtrendofthereconstructedatmosphericCO2concentrationcloselyreflectedthelong-termvariationofatmosphericCO2concentrationrecordedbothbeforeandaftertheIndustrialRevolution.Between1685and1840theevaluatedatmosphericCO2concentrationwasstable,butafter1840itexhibitedarapidincrease.Givenalongerδ13Cannualtimeseriesoftreerings,itwasfeasibletorebuildarepresentativetimeseriestodescribetheatmosphericCO2concentrationforanearlierperiodandforyearsthatwerenotintheicecorerecord.
简介:对香蕉束顶病毒(BBTV)广州分离物MGHDNA组分6全序列进行了克隆及序列分析。并对来自广州、海南、台湾、澳大利亚及印度的BBTV组分6进行了分析,结果表明:BBTV组分6都含有CR-SL(stem-loopcommonregions),CR-M(majorcommonregions)结构等典型的特征序列。BBTV组分6的核苷酸全序列、开放阅读框(ORF)核苷酸、CR-M核苷酸序列及其氨基酸序列系统进化树结果显示,BBTV分离物可分为2个组群:亚洲组和南太平洋组。CR-M结构在2个组群间有明显的差异,南太平洋组分离物的CR-M结构中有一段不完全保守的16个核苷酸的重复序列,而在亚洲组的分离物中这个序列并不重复。对BBTV组分6蛋白质进行了二级结构预测和理化性质分析发现,这2个类群蛋白质的二级结构有差异,但是理化性质无明显差异。
简介:西红花总苷是栀子果实中的次生代谢产物,具有重要的药理作用,也是国际流行的天然色素"栀子黄"的主要成分。番茄红素β-环化酶b(lycopeneβ-cyclase,LCYb)催化合成了西红花总苷代谢途径的前体化合物-β-胡萝卜素。本研究利用RACE技术,从栀子果实中克隆了一条长1672bp的序列,含有一个1500bp的开放阅读框,编码499个氨基酸组成的蛋白质。该蛋白具有番茄红素β-环化酶的结构域,分子量为56.39kD,N端有一个40个氨基酸组成的质体定位的信号肽,属于LCYb亚家族,因此命名为GjLCYb2。进行密码子优化后,利用两种原核表达系统诱导GjLCYb2融合蛋白表达,pSYNO-1系统可以在大肠杆菌中表达出可溶蛋白,pET-28a(+)系统表达的蛋白以包涵体形式存在。荧光绝对定量qPCR检测结果表明,在栀子果实发育成熟的过程中,GjLCYb2基因的表达量变化与西红花总苷的合成量变化趋势一致,表明GjLCYb2基因可以作为遗传操作的靶点,进行栀子果实中西红花总苷生物合成途径的调控。
简介:Bacterialleafblightofrice(BLB),causedbyXanthomonasoryzaepv.oryzae,isoneofthemostdestructivediseasesinAsianricefields.Ahigh-qualityricevariety,LT2,wasusedastherecipientparent.IRBB21,whichcarriestheXa21gene,wasusedasthedonorparent.TheresistancegeneXa21wasintroducedintoLT2bymarker-assistedbackcrossing.ThreeXooraceswereusedtoinoculatetheimprovedlinesfollowingtheclippingmethod.ElevenBC3F3linescarryingXa21wereobtainedbasedonmolecularmarkersandagronomicperformance.The11linesweretheninoculatedwiththethreeXooraces.Allthe11improvedlinesshowedbetterresistancetoBLBthantherecipientparentLT2.BasedonthelevelofresistancetoBLBandtheiragronomicperformance,fivelines(BC3F35.1.5.1,BC3F35.1.5.12,BC3F38.5.6.44,BC3F39.5.4.1andBC3F39.5.4.23)wereselectedasthemostpromisingforcommercialrelease.Theseimprovedlinescouldcontributetoriceproductionintermsoffoodsecurity.