植物環(huán)核苷酸離子門控通道的研究進(jìn)展摘要：環(huán)核苷酸門控離子通道（cyclicnucleotide-gatedchannels,CNGCs）在植物和動物體中廣泛存在，屬于非選擇性陽離子通道的一種，能直接被細(xì)胞內(nèi)信使小分子-核苷酸（cAMP和cGMP）活化。這種通道蛋白包含6個跨膜α-螺旋，其C端各具有一個交疊的環(huán)核苷酸與鈣調(diào)蛋白結(jié)合區(qū)。CNGCs在植物的生長發(fā)育中有著極其重要的作用，在調(diào)節(jié)花粉正常發(fā)育過程、維持體內(nèi)的離子穩(wěn)態(tài)、抵御生物脅迫和非生物脅迫等方面均發(fā)揮著重要作用。本文從結(jié)構(gòu)、分類、調(diào)控以及功能等方面綜述了植物中CNGCs近些年取得的一些研究進(jìn)展。關(guān)鍵詞：CGCNs，非選擇性陽離子通道，生長發(fā)育，調(diào)節(jié)，生物脅迫Abstract：Cyclicnucleotide-gatedchannels(CNGCs)iswidespreadinplantsandanimals.Itisakindofnonselectivecationchannels,whichcandirectlybeactivatedbyintracellularmessengermolecules-nucleotides(cAMPandcGMP).ThischannelproteincontainssixtransmembranealphahelixandtheCterminalhasanoverlappingcyclicnucleotideandcalmodulincombinationdomains.CNGCsplaysanextremelyimportantroleinregulatingthegrowthanddevelopmentofplantsandthenormalpollendevelopmentprocess.Moreover,italsomaintainsionhomeostasisinthebodyandresistsbiologicalandabioticstresses.Inthispaper,thetrendinCNGCsofplantsinrecentyearswasreviewedintermsofstructure,classification,regulationandfunctionKeywords：CGCNs,Nonselectivecationchannel,Growthanddevelopment,regulation,Bioticstress圖1所示，植物CNGC包含6個跨膜α-螺旋（S1-S6），在S5-S6的中間區(qū)域存在一個保守的環(huán)狀結(jié)構(gòu)(Ploop)，其C端還包含了CNBD結(jié)合域和CaMBD結(jié)合域。此外，植物CNGC中的環(huán)狀區(qū)域可能對離子的選擇性具有一定的影響，是植物CNGC所具有的一個重要特征，能夠與其他離子通道區(qū)別開來ADDINEN.CITEADDINEN.CITE.DATA[8-10]。與動物CNGC有所區(qū)別的是，植物CNGC的鈣調(diào)素結(jié)合域（Calmodulin-bindingdomain，CaMBD）位于其結(jié)構(gòu)的C端，而動物CNGC的CaMBD位于其N端，這就意味著調(diào)節(jié)蛋白質(zhì)活性的機(jī)制在動物和植物CNGCs之間可能有著不同的進(jìn)化。2植物CNGC的分類圖中At為擬南芥,Os為水稻,Nt為煙草,HvCBT1為大麥鈣調(diào)素結(jié)合轉(zhuǎn)運(yùn)蛋白。水稻CNGC中,a、b、c表示在同一條染色體上的不同的CNGC。模式植物擬南芥的CNGC基因家族里總共擁有20個成員(CNGC1-CNGC20),在擬南芥的不同器官和組織中均廣泛分布。不僅能參與調(diào)控擬南芥的生長和發(fā)育，還能與外界環(huán)境相互作用ADDINEN.CITE<EndNote><Cite><Author>Kaplan</Author><Year>2007</Year><RecNum>12</RecNum><DisplayText><styleface="superscript">[11]</style></DisplayText><record><rec-number>12</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588067965">12</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Kaplan,B.</author><author>Sherman,T.</author><author>Fromm,H.</author></authors></contributors><auth-address>NiritSeedsLtd.,MoshavHadar-Ham42935,Israel.boazk@</auth-address><titles><title>Cyclicnucleotide-gatedchannelsinplants</title><secondary-title>FEBSLett</secondary-title></titles><periodical><full-title>FEBSLett</full-title></periodical><pages>2237-46</pages><volume>581</volume><number>12</number><edition>2007/02/27</edition><keywords><keyword>AminoAcidSequence</keyword><keyword>Arabidopsis/genetics/metabolism</keyword><keyword>ArabidopsisProteins/chemistry/genetics/metabolism</keyword><keyword>Calcium/metabolism</keyword><keyword>Calmodulin/metabolism</keyword><keyword>CyclicNucleotide-GatedCationChannels</keyword><keyword>IonChannels/chemistry/genetics/*metabolism</keyword><keyword>Models,Molecular</keyword><keyword>MolecularSequenceData</keyword><keyword>Nucleotides,Cyclic/*metabolism</keyword><keyword>Phylogeny</keyword><keyword>PlantDevelopment</keyword><keyword>PlantProteins/chemistry/genetics/*metabolism</keyword><keyword>Plants/genetics/*metabolism</keyword><keyword>SequenceHomology,AminoAcid</keyword><keyword>SignalTransduction</keyword></keywords><dates><year>2007</year><pub-dates><date>May25</date></pub-dates></dates><isbn>0014-5793(Print) 0014-5793(Linking)</isbn><accession-num>17321525</accession-num><urls><related-urls><url>/pubmed/17321525</url></related-urls></urls><electronic-resource-num>10.1016/j.febslet.2007.02.017</electronic-resource-num></record></Cite></EndNote>[11]。已有的研究表明，水稻、大麥、卷柏松、玉米、煙草等植物中均具有CNGC的同源序列。最新的研究發(fā)現(xiàn)，煙草基因組中具有35個CNGC基因，可將其分為4個系統(tǒng)發(fā)育組，其中有圖中At為擬南芥,Os為水稻,Nt為煙草,HvCBT1為大麥鈣調(diào)素結(jié)合轉(zhuǎn)運(yùn)蛋白。水稻CNGC中,a、b、c表示在同一條染色體上的不同的CNGC。圖圖2植物CNGC家族分類圖（Talke等人2003）擬南芥CNGC家族中各成員的氨基酸序列存在著一定的差別，根據(jù)其序列的相似度可將其編碼的蛋白質(zhì)歸類到4個亞家族。例如，將CNGC1、CNGC3、CNGC10、CNGC11、CNGC12和CNGC13等歸類于亞家族Ⅰ；將CNGC5、CNGC6、CNGC7、CNGC8、CNGC9歸類于亞家族Ⅱ；將CNGC14、CNGC15、CNGC16、CNGC17、CNGC18歸類于亞家族Ⅲ。其中，第Ⅰ、第Ⅱ、第Ⅲ亞家族具有很高的相似性，然而與前面三個亞家族有所區(qū)別的是，第Ⅳ亞家族的4個成員（CNGC2、CNGC4、CNGC19、CNGC20）之間，以及與其它3個亞家族的成員之間的相似性較小。此外，第Ⅳ亞家族又可被分為兩個類群，其中，CNGC19和CNGC20屬于類群ⅣA，CNGC2和CNGC4屬于類群ⅣBADDINEN.CITE<EndNote><Cite><Author>P</Author><Year>2001</Year><RecNum>17</RecNum><DisplayText><styleface="superscript">[13]</style></DisplayText><record><rec-number>17</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588166730">17</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>M?serP</author><author>ThomineS</author><author>SchroederJI</author><author>WardJM</author><author>HirschiK</author><author>SzeH</author><author>TalkeIN</author><author>AmtmannA</author><author>MaathuisFJ</author><author>SandersD</author><author>HarperJF</author><author>TchieuJ</author><author>GribskovM</author><author>PersansMW</author><author>SaltDE</author><author>KimSA</author><author>GuerinotML</author></authors></contributors><auth-address>DivisionofBiology,CellandDevelopmentalBiologySectionandCenterforMolecularGenetics,UniversityofCalifornia,SanDiego,LaJolla,California92093-0116,USA.</auth-address><titles><title>PhylogeneticrelationshipswithincationtransporterfamiliesofArabidopsis</title><secondary-title>Plantphysiology</secondary-title></titles><periodical><full-title>Plantphysiology</full-title></periodical><volume>126</volume><number>4</number><keywords><keyword>Non-programmatic</keyword></keywords><dates><year>2001</year></dates><isbn>0032-0889</isbn><urls></urls><remote-database-provider>Cnki</remote-database-provider></record></Cite></EndNote>[13]。植物CNGC的調(diào)控以及調(diào)節(jié)因子3.1植物CNGC的調(diào)控機(jī)制CNGC的活性是通過cGMP、cAMP或CaM與CNBD的可逆結(jié)合來進(jìn)行調(diào)節(jié)，從而變構(gòu)導(dǎo)致通道開放。CNGC作為植物信號轉(zhuǎn)導(dǎo)級聯(lián)系統(tǒng)中的一個極其重要的組成部分，參與了預(yù)防病原菌入侵的早期反應(yīng)。通過對Ca2+的內(nèi)流進(jìn)行調(diào)控，CNGC能將細(xì)胞外的信號轉(zhuǎn)變?yōu)榘麅?nèi)信號，從而進(jìn)一步調(diào)控細(xì)胞的生理活動ADDINEN.CITEADDINEN.CITE.DATA[14-16]。研究發(fā)現(xiàn)，一般情況下，在CNGCs的C末端，當(dāng)cNMPs與CNBD進(jìn)行綁定的時候，會發(fā)生變構(gòu)調(diào)節(jié)使通道打開，從而活化CNGCs，使得細(xì)胞外的Ca2+內(nèi)流。當(dāng)細(xì)胞胞內(nèi)的Ca2+濃度超出一定范圍后，CaM在CaMBD處結(jié)合CNGCs，通過限制cNMPs結(jié)合CNBD從而鈍化通道門控ADDINEN.CITEADDINEN.CITE.DATA[17,18]。FischerADDINEN.CITE<EndNote><Cite><Author>Fischer</Author><Year>2013</Year><RecNum>22</RecNum><DisplayText><styleface="superscript">[19]</style></DisplayText><record><rec-number>22</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588169932">22</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Fischer,C.</author><author>Kugler,A.</author><author>Hoth,S.</author><author>Dietrich,P.</author></authors></contributors><auth-address>MolekularePflanzenphysiologieandErlangenCenterofPlantScience,DepartmentBiology,Friedrich-Alexander-UniversitatErlangen-Nurnberg,Staudtstrasse5,D-91058Erlangen,Germany.</auth-address><titles><title>AnIQdomainmediatestheinteractionwithcalmodulininaplantcyclicnucleotide-gatedchannel</title><secondary-title>PlantCellPhysiol</secondary-title></titles><periodical><full-title>PlantCellPhysiol</full-title></periodical><pages>573-84</pages><volume>54</volume><number>4</number><edition>2013/02/07</edition><keywords><keyword>Arabidopsis/genetics/*metabolism</keyword><keyword>ArabidopsisProteins/genetics/metabolism</keyword><keyword>Calcium/metabolism</keyword><keyword>Calmodulin/genetics/*metabolism</keyword><keyword>CellMembrane/metabolism</keyword><keyword>CyclicNucleotide-GatedCationChannels/genetics/*metabolism</keyword><keyword>ProteinBinding</keyword></keywords><dates><year>2013</year><pub-dates><date>Apr</date></pub-dates></dates><isbn>1471-9053(Electronic) 0032-0781(Linking)</isbn><accession-num>23385145</accession-num><urls><related-urls><url>/pubmed/23385145</url></related-urls></urls><custom2>PMC3612182</custom2><electronic-resource-num>10.1093/pcp/pct021</electronic-resource-num></record></Cite></EndNote>[19]等學(xué)者發(fā)現(xiàn)，擬南芥的CNGC20以依賴Ca2+的方式與CaM結(jié)合，并與所有AtCaM壓型相互作用，但卻并不與CaM相似蛋白CML8和CML9發(fā)生相互作用。根據(jù)他們的綠色熒光蛋白（GFP）融合CNGC20蛋白的定位數(shù)據(jù)證明，這種相互作用發(fā)生在質(zhì)膜上，CaM結(jié)合位點被定位到一個異亮氨酸谷氨酰胺（IQ）基序，這在植物的CNGCs的研究中還沒有被發(fā)現(xiàn)。他們的結(jié)果表明，與目前研究的CNGCs中環(huán)狀核苷酸和CaM的重疊結(jié)合位點相比，它們在CNGC20中是按順序排列的。兩種替代的CaM結(jié)合模式的存在表明，植物CNGCs的配體門控比先前預(yù)期的更為復(fù)雜。由于IQ域在植物CNGCs中是保守的，該域增加了Ca2+依賴的通道控制機(jī)制的可變性，強(qiáng)調(diào)了這個基因家族的功能多樣性。3.2植物CNGC的調(diào)控因子多年來，對植物細(xì)胞中第二信使環(huán)核苷酸受體的本質(zhì)一直都尚未有一個明確的定義。隨著近些年來的研究發(fā)現(xiàn)，環(huán)核苷酸（cNMPs），如cAMP和cGMP，可能是植物中許多信號通路的重要元件，能參與植物的生長和發(fā)育過程，以及對各種壓力的反應(yīng)ADDINEN.CITEADDINEN.CITE.DATA[20]。有學(xué)者認(rèn)為CNGCs可能執(zhí)行著cNMPs受體的功能。然而這一說法眾說紛紜，答案尚未能完全統(tǒng)一，盡管如此，但還是有一些研究的發(fā)現(xiàn)能為這一說法提供證據(jù)。對模式植物擬南芥突變體的研究發(fā)現(xiàn)表明，CNGC能參與植物對病原菌信號響應(yīng)的級聯(lián)效應(yīng)ADDINEN.CITEADDINEN.CITE.DATA[21-23]。通過采用膜片鉗技術(shù)系統(tǒng)地測定了野生型擬南芥細(xì)胞中CNGC以及異源表達(dá)野生型擬南芥CNGC中Ca2+的含量，測定結(jié)果顯示，這兩種細(xì)胞類型的CNGC均能夠被cAMP激活A(yù)DDINEN.CITE<EndNote><Cite><Author>劉海嬌</Author><Year>2015</Year><RecNum>72</RecNum><DisplayText><styleface="superscript">[24]</style></DisplayText><record><rec-number>72</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588350660">72</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>劉海嬌</author><author>杜立群</author><author>林金星</author><author>李瑞麗</author></authors></contributors><auth-address>中國科學(xué)院植物研究所;杭州師范大學(xué)生命與環(huán)境科學(xué)學(xué)院;北京林業(yè)大學(xué)生物科學(xué)與技術(shù)學(xué)院;</auth-address><titles><title>植物環(huán)核苷酸門控離子通道及其功能研究進(jìn)展</title><secondary-title>植物學(xué)報</secondary-title></titles><periodical><full-title>植物學(xué)報</full-title></periodical><pages>779-789</pages><volume>50</volume><number>06</number><keywords><keyword>環(huán)核苷酸門控離子通道</keyword><keyword>植物</keyword><keyword>分類</keyword><keyword>調(diào)控因子</keyword><keyword>生物學(xué)功能</keyword></keywords><dates><year>2015</year></dates><isbn>1674-3466</isbn><call-num>11-5705/Q</call-num><urls></urls><remote-database-provider>Cnki</remote-database-provider></record></Cite></EndNote>[24]。當(dāng)利用對Ca2+敏感的水母熒光蛋白去檢測細(xì)胞質(zhì)中Ca2+的濃度時，也出現(xiàn)了與上述的研究相似的結(jié)果，這就說明了，cAMP能誘導(dǎo)擬南芥胞質(zhì)中Ca2+濃度水平升高。cGMP雖然也可能參與了CNGCs對植物的調(diào)控過程，但是其功能可能與cAMP有所區(qū)別。用病原菌感染擬南芥葉片細(xì)胞，幾分鐘后，發(fā)現(xiàn)cGMP的含量并沒有什么變化ADDINEN.CITEADDINEN.CITE.DATA[25]。然而，在用病原菌感染植物很長一段時間后，cGMP的含量才有所上升ADDINEN.CITE<EndNote><Cite><Author>Meier</Author><Year>2009</Year><RecNum>76</RecNum><DisplayText><styleface="superscript">[26]</style></DisplayText><record><rec-number>76</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588352332">76</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Meier,S.</author><author>Madeo,L.</author><author>Ederli,L.</author><author>Donaldson,L.</author><author>Pasqualini,S.</author><author>Gehring,C.</author></authors></contributors><auth-address>SouthAfricanNationalInstituteofBioinformatics,Bellville,SouthAfrica.</auth-address><titles><title>DecipheringcGMPsignaturesandcGMP-dependentpathwaysinplantdefence</title><secondary-title>PlantSignalBehav</secondary-title></titles><periodical><full-title>PlantSignalBehav</full-title></periodical><pages>307-9</pages><volume>4</volume><number>4</number><edition>2009/10/02</edition><keywords><keyword>3',5'-cyclicmonophosphate(cGMP)</keyword><keyword>ethylene</keyword><keyword>nitricoxide</keyword><keyword>ozone</keyword><keyword>plantstress</keyword><keyword>salicylicacid</keyword></keywords><dates><year>2009</year><pub-dates><date>Apr</date></pub-dates></dates><isbn>1559-2324(Electronic) 1559-2316(Linking)</isbn><accession-num>19794847</accession-num><urls><related-urls><url>/pubmed/19794847</url></related-urls></urls><custom2>PMC2664491</custom2><electronic-resource-num>10.4161/psb.4.4.8066</electronic-resource-num></record></Cite></EndNote>[26]。有學(xué)者利用雙電極電壓鉗技術(shù)測定了非洲爪蟾卵母細(xì)胞異種表達(dá)系統(tǒng)中CNGC11和CNGC12的通道活性。他們的結(jié)果表明，cNMPs對非洲爪蟾卵母細(xì)胞中CNGC11和CNGC12的活性沒有影響。然而，雖然CNGC11的活性不受與CaM共表達(dá)的影響，但是當(dāng)CaM1在卵母細(xì)胞中共表達(dá)時，CNGC12的活性顯著地增強(qiáng)ADDINEN.CITE<EndNote><Cite><Author>Zhang</Author><Year>2019</Year><RecNum>34</RecNum><DisplayText><styleface="superscript">[27]</style></DisplayText><record><rec-number>34</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588171156">34</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Zhang,Z.</author><author>Hou,C.</author><author>Tian,W.</author><author>Li,L.</author><author>Zhu,H.</author></authors></contributors><auth-address>CollegeofLifeSciences,CapitalNormalUniversity,Beijing,China.</auth-address><titles><title>ElectrophysiologicalStudiesRevealedCaM1-MediatedRegulationoftheArabidopsisCalciumChannelCNGC12</title><secondary-title>FrontPlantSci</secondary-title></titles><periodical><full-title>FrontPlantSci</full-title></periodical><pages>1090</pages><volume>10</volume><edition>2019/10/02</edition><keywords><keyword>Arabidopsis</keyword><keyword>Cngc12</keyword><keyword>Ca2+channelactivity</keyword><keyword>CaM1</keyword><keyword>cyclicnucleotidemonophosphates</keyword></keywords><dates><year>2019</year></dates><isbn>1664-462X(Print) 1664-462X(Linking)</isbn><accession-num>31572412</accession-num><urls><related-urls><url>/pubmed/31572412</url></related-urls></urls><custom2>PMC6749817</custom2><electronic-resource-num>10.3389/fpls.2019.01090</electronic-resource-num></record></Cite></EndNote>[27]。目前的研究并沒有直接的證據(jù)表明植物CNGC的活性受cNMPs的調(diào)控，只是有這一種可能，至于最終的結(jié)果如何，還需要更多的實驗去驗證。CaM作為真核生物中一種普遍的Ca2+感受器，被認(rèn)為能夠調(diào)控CNGC陽離子的進(jìn)出。細(xì)胞質(zhì)內(nèi)Ca2+含量在病原菌入侵后會明顯地增多，通過激活下游Ca2+依賴性的生理生化反應(yīng)來調(diào)控細(xì)胞相關(guān)的生理過程，同時，被激活的CaM也能對鈣信號進(jìn)行反饋抑制。CaM通常是作為Ca2+通道的一種傳感器，能對Ca2+的水平變化進(jìn)行自我調(diào)控，并能對一些特異的刺激做出反應(yīng)。HuaADDINEN.CITE<EndNote><Cite><Author>Hua</Author><Year>2003</Year><RecNum>80</RecNum><DisplayText><styleface="superscript">[28]</style></DisplayText><record><rec-number>80</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588435545">80</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Hua,B.G.</author><author>Mercier,R.W.</author><author>Leng,Q.</author><author>Berkowitz,G.A.</author></authors></contributors><auth-address>AgriculturalBiotechnologyLaboratory,DepartmentofPlantScience,UniversityofConnecticut,Connecticut06269-4163,USA.</auth-address><titles><title>Plantsdoitdifferently.Anewbasisforpotassium/sodiumselectivityintheporeofanionchannel</title><secondary-title>PlantPhysiol</secondary-title></titles><periodical><full-title>PlantPhysiol</full-title></periodical><pages>1353-61</pages><volume>132</volume><number>3</number><edition>2003/07/15</edition><keywords><keyword>AminoAcidSequence</keyword><keyword>Animals</keyword><keyword>ArabidopsisProteins/chemistry/genetics/*metabolism</keyword><keyword>CellLine</keyword><keyword>ElectricConductivity</keyword><keyword>Humans</keyword><keyword>*IonChannelGating</keyword><keyword>Models,Molecular</keyword><keyword>MolecularSequenceData</keyword><keyword>Oocytes</keyword><keyword>PotassiumChannels/chemistry/genetics/*metabolism</keyword><keyword>ProteinConformation</keyword><keyword>SequenceAlignment</keyword><keyword>SodiumChannels/chemistry/genetics/*metabolism</keyword><keyword>Structure-ActivityRelationship</keyword><keyword>Xenopuslaevis</keyword></keywords><dates><year>2003</year><pub-dates><date>Jul</date></pub-dates></dates><isbn>0032-0889(Print) 0032-0889</isbn><accession-num>12857817</accession-num><urls></urls><custom2>PMC167075</custom2><electronic-resource-num>10.1104/pp.103.020560</electronic-resource-num><remote-database-provider>NLM</remote-database-provider><language>eng</language></record></Cite></EndNote>[28]等人的研究發(fā)現(xiàn)，CNGCs能被細(xì)胞質(zhì)內(nèi)增多的Ca2+/CaM所抑制，這可能是因為Ca2+/CaM阻礙了病原菌所響應(yīng)的信號級聯(lián)中環(huán)核苷酸對CNGCs的激活作用ADDINEN.CITE<EndNote><Cite><Author>Ma</Author><Year>2011</Year><RecNum>41</RecNum><DisplayText><styleface="superscript">[17]</style></DisplayText><record><rec-number>41</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588327235">41</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Ma,W.</author><author>Berkowitz,G.A.</author></authors></contributors><auth-address>DepartmentofEnergy,PlantResearchLaboratory,MichiganStateUniversity,EastLansing,MI48824,USA.mawei@</auth-address><titles><title>Ca2+conductionbyplantcyclicnucleotidegatedchannelsandassociatedsignalingcomponentsinpathogendefensesignaltransductioncascades</title><secondary-title>NewPhytol</secondary-title></titles><periodical><full-title>NewPhytol</full-title></periodical><pages>566-72</pages><volume>190</volume><number>3</number><edition>2010/12/21</edition><keywords><keyword>Calcium/*metabolism</keyword><keyword>CyclicNucleotide-GatedCationChannels/*metabolism</keyword><keyword>Host-PathogenInteractions/*immunology</keyword><keyword>Models,Biological</keyword><keyword>Plants/*immunology/*metabolism</keyword><keyword>SignalTransduction/*immunology</keyword></keywords><dates><year>2011</year><pub-dates><date>May</date></pub-dates></dates><isbn>1469-8137(Electronic) 0028-646X(Linking)</isbn><accession-num>21166809</accession-num><urls><related-urls><url>/pubmed/21166809</url></related-urls></urls><electronic-resource-num>10.1111/j.1469-8137.2010.03577.x</electronic-resource-num></record></Cite></EndNote>[17]。AliADDINEN.CITEADDINEN.CITE.DATA[21]等人所做的電生理學(xué)實驗顯示，Ca2+在施加CaM拮抗劑后會不斷內(nèi)流。這些研究表明，CaM可能對CNGC具有調(diào)控作用。4植物CNGC的功能的研究進(jìn)展CNGC對植物生長發(fā)育的影響cNMPs在動物的嗅覺、味覺、感官等諸多重要的生理活動中起著關(guān)鍵的作用。動物CNGCs在神經(jīng)和非神經(jīng)細(xì)胞的各個區(qū)域中都有表達(dá)，同樣地，cAMP和cGMP也與重要的植物生理過程的調(diào)控有關(guān)，如氣孔功能、葉綠體發(fā)育、赤霉素信號轉(zhuǎn)導(dǎo)和生殖過程等ADDINEN.CITE<EndNote><Cite><Author>Martinez-Atienza</Author><Year>2007</Year><RecNum>83</RecNum><DisplayText><styleface="superscript">[29]</style></DisplayText><record><rec-number>83</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588439177">83</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Martinez-Atienza,J.</author><author>VanIngelgem,C.</author><author>Roef,L.</author><author>Maathuis,F.J.</author></authors></contributors><auth-address>BiologyDepartment;UniversityofYork;York,UnitedKingdom.</auth-address><titles><title>Plantcyclicnucleotidesignalling:factsandfiction</title><secondary-title>PlantSignalBehav</secondary-title></titles><periodical><full-title>PlantSignalBehav</full-title></periodical><pages>540-3</pages><volume>2</volume><number>6</number><edition>2007/11/01</edition><keywords><keyword>cAMP</keyword><keyword>cGMP</keyword><keyword>cyclicnucleotide</keyword><keyword>kinase</keyword><keyword>signalling</keyword></keywords><dates><year>2007</year><pub-dates><date>Nov</date></pub-dates></dates><isbn>1559-2316(Print) 1559-2316(Linking)</isbn><accession-num>19704553</accession-num><urls><related-urls><url>/pubmed/19704553</url></related-urls></urls><custom2>PMC2634363</custom2><electronic-resource-num>10.4161/psb.2.6.4789</electronic-resource-num></record></Cite></EndNote>[29]。CNGC參與了許多植物的生理過程，從花粉尖端極化生長，根毛的尖端生長，葉片衰老再到豆科植物根的根瘤菌與菌根共生等方向都有所研究ADDINEN.CITEADDINEN.CITE.DATA[30-33]。然而，就目前而言，關(guān)于CNGC對植物生長發(fā)育的影響的研究主要集中在植物的生殖過程，尤其是花粉管的生長和發(fā)育。遺傳證據(jù)表明?；ǚ酃艿纳L需需要CNGC18的參與，CNGC18主要是在花粉中進(jìn)行表達(dá)，缺乏CNGC18的擬南芥突變體表現(xiàn)出雄性不育，不育的根本原因被確定為花粉管生長的缺陷，導(dǎo)致花粉管彎曲、短小、常薄ADDINEN.CITE<EndNote><Cite><Author>Frietsch</Author><Year>2007</Year><RecNum>84</RecNum><DisplayText><styleface="superscript">[33]</style></DisplayText><record><rec-number>84</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588441529">84</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Frietsch,S.</author><author>Wang,Y.F.</author><author>Sladek,C.</author><author>Poulsen,L.R.</author><author>Romanowsky,S.M.</author><author>Schroeder,J.I.</author><author>Harper,J.F.</author></authors></contributors><auth-address>BiochemistryDepartmentMS200,UniversityofNevada,Reno,NV89557,USA.</auth-address><titles><title>Acyclicnucleotide-gatedchannelisessentialforpolarizedtipgrowthofpollen</title><secondary-title>ProcNatlAcadSciUSA</secondary-title></titles><periodical><full-title>ProcNatlAcadSciUSA</full-title></periodical><pages>14531-6</pages><volume>104</volume><number>36</number><edition>2007/08/30</edition><keywords><keyword>Arabidopsis/cytology/genetics/growth&development/metabolism</keyword><keyword>Calcium/metabolism</keyword><keyword>CellMembrane/metabolism</keyword><keyword>*CellPolarity</keyword><keyword>CyclicNucleotide-GatedCationChannels</keyword><keyword>Escherichiacoli/genetics/metabolism</keyword><keyword>GeneExpression</keyword><keyword>GeneExpressionRegulation,Plant</keyword><keyword>IonChannelGating</keyword><keyword>IonChannels/classification/genetics/*metabolism</keyword><keyword>Pollen/cytology/*growth&development/*metabolism</keyword></keywords><dates><year>2007</year><pub-dates><date>Sep4</date></pub-dates></dates><isbn>0027-8424(Print) 0027-8424</isbn><accession-num>17726111</accession-num><urls></urls><custom2>PMC1964830</custom2><electronic-resource-num>10.1073/pnas.0701781104</electronic-resource-num><remote-database-provider>NLM</remote-database-provider><language>eng</language></record></Cite></EndNote>[33]。鈣依賴性蛋白激酶（CPK32）作為Ca2+的下游效應(yīng)分子，控制著花粉管的極性生長。CPK32和CNGC18的共同表達(dá)使得非洲爪蟾卵母細(xì)胞CNGC18的激活，而CNCG18的單獨表達(dá)并沒有表現(xiàn)出明顯的鈣通道活性，這個結(jié)果說明了CPK32和CNGC18的共表達(dá)具有協(xié)同作用，這也提供了一個潛在的前饋機(jī)制，在花粉管的極性生長中，鈣激活的CPK32激活CNGC18，然后再進(jìn)一步促進(jìn)對Ca2+的吸收ADDINEN.CITEADDINEN.CITE.DATA[34]。GaoADDINEN.CITEADDINEN.CITE.DATA[35]等人的研究發(fā)現(xiàn)，在8個Ca2+通道中（包括6個CNGCs和2個谷氨酸受體通道），CNGC18是花粉管誘導(dǎo)的唯一必須通道。開花植物的成功受精和繁殖依賴于花粉管的正確延伸，而花粉管的生長與花粉管頂端的鈣離子波動密切相關(guān)，鈣離子波動信號對于維持花粉管極性延伸和完成生命繼代延續(xù)起到了十分關(guān)鍵的作用。雖然已經(jīng)清楚CNGC18在植物花粉管的發(fā)育中有著重要的作用，但如何維持花粉管頂端鈣離子的波動的分子機(jī)制尚未清楚。PanADDINEN.CITEADDINEN.CITE.DATA[36]等人的研究發(fā)現(xiàn)，花粉管特異性環(huán)核苷酸門控通道（CNGC18，CNGC8和CNGC7）與CaM2/3能共同構(gòu)成鈣波動信號編碼器，具有鈣依賴循環(huán)開關(guān)的波動特性。鈣通道的開啟或關(guān)閉受細(xì)胞內(nèi)Ca2+濃度的調(diào)控。在低濃度鈣離子的情形中時，Apo-CaM2與CNGC18-CNGC8復(fù)合物相互作用，從而激活通道，導(dǎo)致鈣離子內(nèi)流；在高濃度鈣離子情形中時，Calcium-bound-CaM2與CNGC18-CNGC8異源四聚體分離，從而關(guān)閉通道。這項研究構(gòu)建了依賴于Ca2+-CaM-CNGCs而形成的鈣波動編碼器的模型，這是植物領(lǐng)域發(fā)現(xiàn)的首個能調(diào)控花粉管節(jié)律延伸的鈣離子信號編碼器，也是首次在植物學(xué)領(lǐng)域發(fā)現(xiàn)的由多蛋白復(fù)合體所組成的依賴鈣離子濃度變化的分子開關(guān)。這一研究發(fā)現(xiàn)不僅揭示了花粉管延伸機(jī)制，也為調(diào)節(jié)其他生理過程的鈣波動編碼器的探索和發(fā)現(xiàn)指明了方向。CNGC在植物免疫反應(yīng)中的作用由于有預(yù)測防御系統(tǒng)和誘導(dǎo)防御系統(tǒng)的存在，植物同其他生物體一樣，能夠免受病原微生物的侵染ADDINEN.CITE<EndNote><Cite><Author>Moeder</Author><Year>2011</Year><RecNum>101</RecNum><DisplayText><styleface="superscript">[37]</style></DisplayText><record><rec-number>101</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588693451">101</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Moeder,W.</author><author>Urquhart,W.</author><author>Ung,H.</author><author>Yoshioka,K.</author></authors></contributors><auth-address>DepartmentofCellandSystemsBiology,UniversityofToronto,25WillcocksStreet,Toronto,ONM5S3B2,Canada.</auth-address><titles><title>Theroleofcyclicnucleotide-gatedionchannelsinplantimmunity</title><secondary-title>MolPlant</secondary-title></titles><periodical><full-title>MolPlant</full-title></periodical><pages>442-52</pages><volume>4</volume><number>3</number><edition>2011/04/05</edition><keywords><keyword>CyclicNucleotide-GatedCationChannels/genetics/*metabolism</keyword><keyword>Phenotype</keyword><keyword>PlantDiseases/genetics/immunology/microbiology</keyword><keyword>PlantImmunity/genetics/*immunology</keyword><keyword>Plants/genetics/immunology/microbiology</keyword><keyword>SignalTransduction/immunology</keyword></keywords><dates><year>2011</year><pub-dates><date>May</date></pub-dates></dates><isbn>1752-9867(Electronic) 1674-2052(Linking)</isbn><accession-num>21459831</accession-num><urls><related-urls><url>/pubmed/21459831</url></related-urls></urls><electronic-resource-num>10.1093/mp/ssr018</electronic-resource-num></record></Cite></EndNote>[37]。Ca2+參與了植物細(xì)胞信號轉(zhuǎn)導(dǎo)的級聯(lián)反應(yīng)，在植物免疫應(yīng)答中，CNGC依賴型Ca2+濃度的升高會導(dǎo)致H2O2和NO等防御分子的產(chǎn)生，從而誘導(dǎo)防御基因的表達(dá)ADDINEN.CITE<EndNote><Cite><Author>Walker</Author><Year>2013</Year><RecNum>98</RecNum><DisplayText><styleface="superscript">[38]</style></DisplayText><record><rec-number>98</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588687835">98</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Walker,R.K.</author><author>Berkowitz,G.A.</author></authors></contributors><auth-address>DepartmentofPhysiologyandBiophysics,CollegeofMedicine,HowardUniversity,Washington,DC,USA.</auth-address><titles><title>Detectionofreactiveoxygenspeciesdownstreamofcyclicnucleotidesignalsinplants</title><secondary-title>MethodsMolBiol</secondary-title></titles><periodical><full-title>MethodsMolBiol</full-title></periodical><pages>245-52</pages><volume>1016</volume><edition>2013/05/18</edition><keywords><keyword>Arabidopsis/cytology/genetics/*metabolism</keyword><keyword>Biochemistry/*methods</keyword><keyword>GeneExpressionRegulation,Plant</keyword><keyword>HydrogenPeroxide/metabolism</keyword><keyword>LuminescentMeasurements</keyword><keyword>Nucleotides,Cyclic/*metabolism</keyword><keyword>Phenols/metabolism</keyword><keyword>PlantStomata/cytology</keyword><keyword>ReactiveOxygenSpecies/*metabolism</keyword><keyword>Real-TimePolymeraseChainReaction</keyword><keyword>*SignalTransduction</keyword><keyword>StainingandLabeling</keyword><keyword>Sulfoxides/metabolism</keyword></keywords><dates><year>2013</year></dates><isbn>1940-6029(Electronic) 1064-3745(Linking)</isbn><accession-num>23681584</accession-num><urls><related-urls><url>/pubmed/23681584</url></related-urls></urls><electronic-resource-num>10.1007/978-1-62703-441-8_17</electronic-resource-num></record></Cite></EndNote>[38]。AtCNGC2的無義突變植株dnd1在被病原體感染時，不僅表現(xiàn)出超敏反應(yīng)（hypersensitivityreaction,HR）表型的缺失，而且表現(xiàn)出機(jī)體的防御反應(yīng)，如水楊酸（SA）濃度的升高，病原體相關(guān)基因的表達(dá)，對毒性和無毒性丁香假單胞菌都展現(xiàn)出很強(qiáng)的抗性ADDINEN.CITEADDINEN.CITE.DATA[39,40]。此外，AtCNGC2將Ca2+導(dǎo)入細(xì)胞，并提供了一個將Ca2+電流與下游NO的產(chǎn)生聯(lián)系起來的模型。NO是一種極其重要的信號分子，能誘導(dǎo)植物對病原體產(chǎn)生先天免疫應(yīng)答。無AtCNGC2功能的擬南芥突變體缺乏這種細(xì)胞膜Ca2+電流，也不產(chǎn)生超敏反應(yīng)ADDINEN.CITEADDINEN.CITE.DATA[21,23]。CNGC4的無義突變體(hlm1/dnd2,HR-likelesionmimicl/defenseno-death2)與CNGC2的突變體具有極其相似的表型，具有抵御而不致死的特征，二者同源性也最高，也具有植物防御的作用ADDINEN.CITEADDINEN.CITE.DATA[41,42]。AtCNGC2和AtCNGC4的無義突變體的研究顯示，這兩個基因可能參與植物抵御病原微生物的信號轉(zhuǎn)導(dǎo)ADDINEN.CITE<EndNote><Cite><Author>Demidchik</Author><Year>2007</Year><RecNum>110</RecNum><DisplayText><styleface="superscript">[43]</style></DisplayText><record><rec-number>110</rec-number><foreign-keys><keyapp="EN"db-id="e5edrtp5vv29s4ezfe4vwad9w55dsa2xt9ps"timestamp="1588867230">110</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Demidchik,V.</author><author>Maathuis,F.J.</author></authors></contributors><auth-address>DepartmentofBiologicalSciences,UniversityofEssexCO43SQ,Colchester,UK.vdemid@essex.ac.uk</auth-address><titles><title>Physiologicalrolesofnonselectivecationchannelsinplants:fromsaltstresstosignallinganddevelopment</title><secondary-title>NewPhytol</secondary-title></titles><periodical><full-title>NewPhytol</full-title></periodical><pages>387-404</pages><volume>175</volume><