简介:全球平均气温的不断上升对陆地生态系统的碳收支产生了深远的影响.本研究基于LI-6400便携式光合仪和密闭箱式法,并通过设置开顶箱(OTCS)增温装置来模拟增温状态,研究了2017青海湖流域的小泊湖高寒湖滨湿地7~9月净生态系统碳交换(NEE)、生态系统呼吸(ER)、总生态系统生产力(GEP)对增温的响应.研究结果表明:1)NEE、ER、GEP均表现为明显的日变化和月变化特征,且在整个研究阶段生态系统表现为碳汇;2)增温对NEE、GEP抑制作用明显,对ER的影响较小,增温处理下的生态系统碳交换与对照相比较弱,从而降低了整个湿地生态系统的碳汇能力.
简介:为研究黄金茶出芽早的分子机制,本研究采用SMART-RACE技术,获得了与解除休眠相关的转录因子CsDAM2基因的全长eDNA序列,并进一步对该氨基酸序列进行了生物信息学分析。研究发现CsDAM2基因全长为1386bp,序列分析表明,该序列含有一个完整的编码区,大小为657bp,编码区GC含量为50.45%。此编码区可以编码分子量为24.86kD的亲水性蛋白,该蛋白由218个氨基酸组成,理论等电点(pI)为8.96。黄金茶CsDAM2蛋白有11个磷酸化位点,属跨膜蛋白,与毛白杨DAM3的相似性为71%,与已登录茶树MADS.box蛋白的一致性为35%。本研究为进一步揭示黄金茶春芽萌发早的分子机制提供了理论依据。
简介:TheimpactsofelevatedtemperatureandCO2onyoungsilverbirch(BetulapendulaRoth)saplingsafter0,25,50or75%artificialdefoliationwereassessedbymeasuringplantheightanddrymassofabovegroundcompartmentsandrootsandvariousmorphologicalandphysiologicalvariables.Defoliationeitherincreasedordecreasedplantgrowthdependingontheseverityofdamageandtheclimatictreatment.At21Cand400mgL-1CO2,defoliatedplantswerenotabletocompensateforthelostfoliage,butgrowthcompensationandadaptationtothechangedconditionsweregreater;growthofyoungdefoliatedsilverbirchsaplingsincreased,whichledtoincreasedheightandatendencytoenhancefinalabovegroundandrootbiomassandleafnitrogenandcarboncontentcomparedtothenondefoliatedcontrols.Nevertheless,theshort-termeffectofthedifferentclimaticconditionsdidnotresultinasignificantovergrowthofdefoliatedplants.AslightincreaseintemperatureandCO2werethemostacceptableconditionsfordefoliatedplants;however,a4CincreasewithcorrespondinglyhigherCO2wasmorestressfulasshownbylessgrowthinheightandbiomassallocationtoleaves,stemsandroots.Thefindingsfromthepilotexperimentaremoreapplicabletoyoungbirchtrees,butstressonyoungtreesmaybereflectedinfuturetreegrowth.
简介:Smallubiquitin-likemodifier(SUMO)-conjugatingenzymesareinvolvedinpost-translationalregulatoryprocessesineukaryotes,includingtheconjugationofSUMOpeptidestoproteinsubstrate(SUMOylation).SUMOylationplaysanimportantroleinimprovingplanttolerancetoabioticstresssuchassalt,drought,heatandcold.Herein,wereportedtheisolationofOsSCE1(LOC_Os10g39120)geneencodingaSUMO-conjugatingenzymefromrice(Oryzasativacv.Nipponbare)anditsfunctionalvalidationinresponsetodroughtstress.TheE2enzyme,OsSCE1,isoneofthreekeyenzymesinvolvedintheconjugationofSUMOtoitstargetproteins.ActivatedSUMOistransferredtothecysteineofanE2enzymeandthentothetargetlysineresidueofthesubstrate,withorwithoutthehelpofanE3SUMOligase.ExpressionofOsSCE1wasstronglyinducedbypolyethyleneglycol6000(PEG6000)treatment,whichsuggestedOsSCE1maybeinvolvedinthedroughtstressresponse.OverexpressionofOsSCE1(OsSCE1-OX)inNipponbarereducedthetolerancetodroughtstress.Conversely,thedroughttolerancewasslightlyimprovedbytheknockdownofOsSCE1(OsSCE1-KD).TheseresultswerefurthersupportedbymeasurementofprolinecontentinOsSCE1-OXandOsSCE1-KDtransgeniclinesunderinduceddroughtstress,whichshowedOsSCE1-KDtransgeniclinesaccumulatedhigherprolinecontentthanthewildtype,whereasOsSCE1-OXlinehadlowerprolinecontentthanthewildtype.ThesefindingssuggestedOsSCE1mayplayaroleasanegativeregulatorinresponsetodroughtstressinrice.
简介:本研究以普通小麦品种‘中国春’染色体组DNA为封阻,用生物素(biotin-16-dUTP)标记的大麦染色体组DNA作为探针,通过基因组原位杂交法解析了来自杂交组合CS×(CS+Betzes2H)杂种后代X99-13的遗传组成,此材料含有42条染色体,其中1条大麦染色体,2条小麦-大麦易位染色体和39条小麦染色体,鉴定为小麦-大麦代换易位系。以小麦第二部分同源群短臂探针psr131进行RFLP分析,结果表明此代换易位系是涉及小麦染色体2B和大麦染色体2H的代换易位。为进一步选育小麦-大麦2H纯合易位系及利用其上的α-淀粉酶抑制蛋白基因打下了坚实的物质基础。
简介:大针茅(Stipagrandis)草原是内蒙古典型草原重要组成部分,对畜牧业的发展和生态环境有重要意义.本文通过野外取样,结合室内分析,对不同草地利用方式下大针茅草原群落功能性状进行了研究,分析了群落植株高度(CWMH)、叶片长度(CWMLL)、叶面积(CWMLA)、叶片碳含量(CWMLCC)、叶片氮含量(CWMLCC)及叶片碳氮比(CWMC/N)6个功能性状指标在不同利用方式下的差异及其相关性,旨在探讨大针茅草原群落功能性状对利用方式的响应.结果表明:与对照(CK)相比,放牧(G)与刈割(M)显著增加了群落叶片长度(CWMLL)及叶片氮含量(CWMLNC)(p〈0.05),显著降低了群落叶片碳含量(CWMLCC)及叶片碳氮比(CWMC/N)(p〈0.05);放牧(G)显著降低了群落植株高度(CWMH)、叶片面积(CWMLA)(p〈0.05);刈割(M)显著增加了群落叶片面积(CWMLA)(p〈0.05).并且,放牧(G)与围封(CK)均表现出植株高度(CWMH)与叶片长度(CWMLL)呈显著或极显著的正相关关系,而刈割使二者关系不显著,使植株高度(CWMH)与叶片面积(CWMLA)二者关系显著;刈割(M)使得叶片碳含量(CWMLCC)与叶片氮含量(CWMLCC)呈极显著的负相关关系.