園藝學(xué)報2004,31(4):543 ~548lcta Horticulturae Sinica乙烯受體與果實成熟調(diào)控魏紹沖’陳昆松'* 羅 云波(!浙江大學(xué)果實分子生理實驗室,農(nóng)業(yè)部園藝植物生長發(fā)育與生物技術(shù)重點開放實驗室,杭州310029;2中國農(nóng)業(yè)大學(xué)食品科學(xué)與營養(yǎng)工程學(xué)院,北京100083 )摘要:綜述了有關(guān)乙烯受體和果實成熟衰老研究的最新進展,主要包括擬南芥乙烯受體和信號轉(zhuǎn)導(dǎo),番茄等果實乙烯受體家族基因的表達與功能研究,果實乙烯受體基因表達的調(diào)節(jié)等,對今后乙烯受體的相.關(guān)研究前景作了展望。乙烯受體轉(zhuǎn)基因等研究結(jié)果表明,乙烯的作用可以在受體水平實現(xiàn)高度調(diào)節(jié)。關(guān)鍵詞:果實成熟;乙烯受體;信號轉(zhuǎn)導(dǎo);綜述中圖分類號:S601 ; Q 946文獻標識碼: A文章編號: 0513-353X ( 2004 ) 04-0543-06 .Ethylene Receptor and Its Regulation in Ripening FruitsWei Shaochong' , Chen Kunsong', and Luo Yunbo2( ' Laboratory of Fruit Molecular Physiology and Biology , Zhejiang University ; The State Agriculture Ministry Laboratory of Horti-cultural Plant Growth , Development and Biotechnology , Hangzhou 310029 , China ; 2 College of Food Science and Nutritional En-gineering , China Agricultural University , Beijing 100083 , China )Abstract : The action of plant hormone ethylene is finally realized through ethylene receptor and its sig-nal transduction. The latest advances in researches on the ethylene receptor and fruit ripening is reviewed inhe present paper. The main contents include : the ethylene receptor and its signal transduction in Arabidopsis,and the expression of ethylene receptors in relation to their functions in ripening fruits. Meanwhile , the pros-pect of ethylene receptor is predicted as well.Key words : Fruit ripening ; Ethylene receptor ; Ethylene signal transduction ; Review植物激素乙烯對植物生長發(fā)育的許多過程,如種子萌發(fā)、幼苗生長、開花、結(jié)實、果實成熟和衰老等有著廣泛而深遠的影響'。乙烯也是-個植物適應(yīng)環(huán)境變化的信號,它調(diào)節(jié)了機械傷和病原反應(yīng)等脅迫反應(yīng)(2,32。Bradford 等4認為植物激素信號可以通過內(nèi)源水平及組織對其感受進行調(diào)節(jié),例如,果實對乙烯的敏感性可隨成熟進程不斷在發(fā)生改變。通過控制乙烯的感受仍可使果實成熟的相關(guān)變化延緩或中斷'5。乙烯的生物合成途徑已經(jīng)于20世紀70年代末被明確, ACC合酶( ACS)和ACC氧化酶( ACO)是乙烯生物合成的兩個關(guān)鍵酶。研究表明, ACS和ACO均由多基因家族編碼,這些基因?qū)Σ煌l(fā)育信號和環(huán)境刺激產(chǎn)生響應(yīng),從而有效地調(diào)節(jié)植物乙烯的生成與作用06-8)。隨著乙烯研究的不斷深入,人們開始逐漸轉(zhuǎn)向乙烯感受和信號轉(zhuǎn)導(dǎo)途徑的研究。通過擬南芥乙烯反應(yīng)不敏感突變體的分析,人們分離得到了一系列關(guān)鍵基因,并進行了大量的分子遺傳學(xué)分析,建立了擬南芥的乙烯信號轉(zhuǎn)導(dǎo)途徑初步輪廓(9。10]。本文綜述近年來乙烯受體研究的新進展及其在果實成熟衰老進程中的調(diào)控途徑。1擬南芥乙烯 受體和信號轉(zhuǎn)導(dǎo)中國煤化工以黑暗條件下乙烯對幼苗的”三重反應(yīng)” (即黑暗.MHC NMH G;在乙烯存在的條件下收稿日期: 2003 -09-20;修回日期:2003-11-06基金項目: 國家重點基礎(chǔ)研究發(fā)展規(guī)劃項目( 973項目) ( G2000046806 );國家自然科學(xué)基金項目( 30270917 );浙江省自然科學(xué)基金重點項目( ZD0004 )*通信陌方數(shù)據(jù)for corespondence ( E-mail : akun@ zju. edu. en)544園藝報31卷發(fā)生表型變化,包括下胚軸膨脹變短,頂端鉤狀芽彎曲加劇，莖桿偏向水平生長)作為篩選手段,人們從擬南芥中分離得到了許多乙烯合成和信號轉(zhuǎn)導(dǎo)發(fā)生改變的突變體"1),隨后CTR112),EIN2[13) , EIN314), ERF115) , ETR1'16)等多個乙烯信號轉(zhuǎn)導(dǎo)相關(guān)基因相繼被克隆。值得注意的是ETR1顯性等位基因突變體的克隆,導(dǎo)致了番茄中包括NR在內(nèi)多個乙烯受體基因類似物的確定[7。ETR1蛋白與原核生物中普遍存在的雙組分系統(tǒng)高度同源,它主要位于細胞的內(nèi)質(zhì)網(wǎng)中18]。在細菌中,由感受器和反應(yīng)調(diào)節(jié)器組成的雙組分系統(tǒng)起到調(diào)節(jié)各種發(fā)育和刺激反應(yīng)的作用‘19]。遺傳和生化證據(jù)均表明ETR1編碼一個乙烯受體。ETR1 是以二聚體的形式存在,且在銅離子參與下表現(xiàn)出與乙烯具有高親和性20-23)。擬南芥的ETR家族由5個受體蛋白組成24-26) ,其相應(yīng)的編碼基因分別為ETR1、ETR2、EIN4、 ERSI 和ERS2。擬南芥乙烯受體蛋白從功能上可分為感受器、組氨酸激酶和反應(yīng)調(diào)節(jié)器3個結(jié)構(gòu)域(27)。(1)感受器(Sensor)結(jié)構(gòu)域:由3個疏水的跨膜節(jié)段組成。該區(qū)域高度保守,現(xiàn)在已知的所有引起乙烯不敏感的受體突變位點都處于這一區(qū)域,在乙烯不敏感的突變體(如etr1-1 )中,乙烯不能與受體蛋白結(jié)合。在這-結(jié)構(gòu)域的N末端中含有形成二聚體和結(jié)合銅離子必須的氨基酸。(2)組氨酸激酶(Histidinekinase,HK)結(jié)構(gòu)域:它比同源的細菌雙組分系統(tǒng)中的HK序列大。激酶結(jié)構(gòu)域由五個被稱為催化中心(H,N,Gl,F,G2)的亞結(jié)構(gòu)域組成。在ETR1和ERS1中包含所有的五個亞結(jié)構(gòu)域,而ETR2、EIN4 和ERS2三個乙烯受體中缺少一個或多個亞結(jié)構(gòu)域。ETR1 在體外可檢測到HK的活性[28] ,這是目前唯-表現(xiàn)HK活性的乙烯受體。理論上講, HK結(jié)構(gòu)域在乙烯信號轉(zhuǎn)導(dǎo)中起著向下游傳遞信息的作用。但是-個明顯的問題是,既然有的受體中不具有HK活性,那么,它們又是如何進行信號轉(zhuǎn)導(dǎo)的,仍不清楚。(3)反應(yīng)調(diào)節(jié)器( Response regulator)結(jié)構(gòu)域:這-結(jié)構(gòu)域中具有自我磷酸化的Asp殘基。與細菌相類似,植物的乙烯受體家族的一些成員中缺乏這-結(jié)構(gòu)域,如擬南芥中ERS家族成員ERS1和ERS2 ,而ETR1、ETR2 和EIN4則包含有反應(yīng)調(diào)節(jié)器結(jié)構(gòu)域。根據(jù)基因敲除( knock-out )對表型( phenotype )影響試驗結(jié)果得出的模式推測(29) :在無乙烯的狀態(tài)下乙烯受體應(yīng)該是有活性的，下游的CTR組分也具有活性,而此時乙烯誘導(dǎo)的相關(guān)基因表達處于被抑制狀態(tài);當乙烯與受體結(jié)合時會使受體及CTR失活,乙烯誘導(dǎo)基因表達的抑制作用也相應(yīng)被解除。然而,因為ERS2類受體無HK活性,所以受體活性的精確調(diào)節(jié)目前還不清楚。2果實乙烯受體研究進展.2.1番茄乙烯受體家族番茄是研究乙烯反應(yīng)和果實成熟衰老的模式植物。目前,番茄的6個乙烯受體基因( LeETRI ~6)已分別被分離和定性‘30-37]。其中LeETR3 (即NR )基因定位在番茄的9號染色體上,序列分析發(fā)現(xiàn)Nr(Neverripe)突變體只是由于NR蛋白36位上單個堿基突變而使Pro變成Leu造成的(37]。Nr突變體除果實不能正常成熟外,還顯示出乙烯不敏感突變株的多效突變效應(yīng),具體表現(xiàn)為:不表現(xiàn)乙烯的三重反應(yīng),葉柄不易脫落,葉和花瓣衰老進程明顯推遲(37]。研究表明,番茄乙烯受體( LeETR )家族的結(jié)構(gòu)與擬南芥乙烯受體家族十分相似,但番茄乙烯受體的各個成員在蛋白質(zhì)水平上差別較大,在序列.上表現(xiàn)出50%以下的同源性,其中從LeETR4和LeETRS兩個成員的序列中推測似乎存在第4個跨膜結(jié)構(gòu)域,這個結(jié)構(gòu)域可能是-個信號序列或者起中國煤化工接傳遞到細胞質(zhì)的作用。其中NR受體蛋白缺少接受器結(jié)構(gòu)域, LeETR4 ~6YHCNMH宅整的HK結(jié)構(gòu)域。盡管各番茄乙烯受體的結(jié)構(gòu)有顯著差異,但試驗已證明除克隆較晚的LeETR6外, 其它均已被證實為乙烯受體,因為它們都已被確定有結(jié)合乙烯的能力38。2.2番茄乙烯受體基因的表達 與功能研究當考慮受體表達對調(diào)節(jié)整個乙烯反應(yīng)的重要性時,需注意以下幾點。首先,乙烯受體在信號轉(zhuǎn)導(dǎo)3期魏紹沖等:乙烯受體與果實成熟調(diào)控545過程中顯然是作為負調(diào)節(jié)因子起作用。在缺乏乙烯的情況下,受體會抑制乙烯誘導(dǎo)的相關(guān)基因表達。根據(jù)這種模式推測組織對乙烯的敏感性與受體水平之間呈負相關(guān)關(guān)系。要解除抑制,應(yīng)當需更多的乙烯使受體失活,反之亦然。另一個需考慮乙烯反應(yīng)的因素是受體有一個較長的與乙烯分離的半衰期，酵母中表達的ETR1測定的半衰期大約是12 h(20]。 這意味著受體一旦與乙烯結(jié)合,它將在較長的一段時間內(nèi)不能抑制乙烯誘導(dǎo)的相關(guān)基因。無論是在果實發(fā)育中或外界刺激下，番茄中的多個乙烯受體基因的表達發(fā)生明顯改變。當乙烯反應(yīng)啟動時,乙烯合成的快速增加會伴隨受體合成的增加。通常當-種植物激素的合成增加或施加某種激素,植物會迅速作出反應(yīng)以降低或解除這種反應(yīng),包括通過酶的合成直接消除激素的作用。例如,對擬南芥使用生長素可以導(dǎo)致生長素結(jié)合酶活性的增加59]。對于乙烯,還不知道會使哪些酶變化,因為它比較容易擴散。由于直到最近其它植物激素的受體基因才被克隆,所以還不知道其它激素的受體在激素增加時是否會出現(xiàn)同樣情況。2.3乙烯受體基因的表達與番茄果實成熟調(diào)節(jié)番茄乙烯受體基因在果實發(fā)育過程中表現(xiàn)出不同的表達模式。LeETR1 和LeETR2在不同發(fā)育時期所有組織中的表達基本保持不變,同時它們的表達不受乙烯誘導(dǎo)調(diào)控,這說明它們可能與果實成熟關(guān)系不密切。相比之下,其余4個基因( LeETR3 ~6)的表達模式則是受乙烯和果實發(fā)育高度調(diào)節(jié)的38。在果實成熟過程中,盛花期子房的NR mRNA具有高水平的表達,隨后趨下降,到果實成熟期其表達水平是子房的20倍(34)。LeETR4 , LeETRS和LeETR6在生殖器官(花和果實)中表達豐富,而在營養(yǎng)器官中表達水平較低(38)。目前對這些受體基因在生殖器官中的顯著高表達所產(chǎn)生的功能還不清楚。近年來,人們還從番茄中分離得到了乙烯信號轉(zhuǎn)導(dǎo)下游CTR1 , EIN3 , EREBP ( ERF1 )等組分同源的相關(guān)基因。Lin等'40]克隆了TCTR2,它與CTR1蛋白有41%的同源性。Zegzouti等41)分離得到了ER50 ,其編碼另一個與CTR1相似的蛋白，并推斷可能有多種MAP3K參與了乙烯作用的調(diào)節(jié)。TCTR2是組成型表達的，不受外源乙烯的誘導(dǎo)(40);而ER50 mRNA則在果實成熟過程中正向調(diào)節(jié)( up-regulated),并受外源乙烯的誘導(dǎo)(41。Alexander 等(42)認為, 番茄乙烯受體可以和與Raf蛋白激酶相似的LeCTR的至少5個家族成員直接作用。此外, Gu等43)還從番茄中分離得到了EREBP的類似物pti4。Tieman 等' 44從番茄中篩選到EIN3基因的類似物L(fēng)eEIL1 , LeEIL2 , LeEIL3基因。結(jié)合擬南芥和番茄乙烯信號轉(zhuǎn)導(dǎo)的研究結(jié)果,我們對乙烯受體基因的表達與果實成熟關(guān)系有了初步認識,即乙烯與膜上受體蛋白的結(jié)合會使乙烯受體及CTR失活，下游的EIL和EREBP等組分則被激活,引起一系列成熟相關(guān)基因的表達,最終導(dǎo)致果實成熟;而在受體蛋白不與乙烯結(jié)合的情況下,乙烯受體和CTR是具有活性的,下游EIL和EREBP組分被抑制不表達,果實不能正常成熟。但番茄果實在成熟階段發(fā)生對乙烯的敏感性與果實中乙烯受體基因的表達模式并不是-致的,相關(guān)調(diào)節(jié)模式還需要進-步試驗證實。2.4其它果實乙烯受體的研究盡管不同植物中乙烯受體有較大差異,但其編碼基因序列中仍存在相對保守的區(qū)域,特別是在其蛋白質(zhì)N-端與乙烯結(jié)合的結(jié)構(gòu)域。除番茄外,人們已相繼從香瓜(45)、西番蓮46.47、 桃48.49)、香蕉(S0)、口果5、蘋果'52]、梨s3.54)、柑橘55、黃瓜[S0]等果實中分離得到了多個乙烯受體同源基因。目前研究結(jié)果表明,乙烯受體基因在這些植物中也可能中國煤化工在。例如，香瓜、西番蓮、桃等果實中目前均已分別分離出了兩個以上的乙MHC N M H G研究的深入，可能每一種果實中將會有更多的乙烯受體基因不斷被克隆。不同類型果實的乙烯受體基因的表達是復(fù)雜多樣的,在西番蓮和桃果實中, ETR類型受體基因PeETR1和Pp-ETR1在果實發(fā)育和成熟過程中是組成型表達,與番茄果實中的LeETR1和LeETR2表達相似,基本不受乙烯生成的影響;但是在香瓜和口果果實中,瓦夜葵型受體基因Cm- ETR1和METR1的表達水平則隨果實成熟進程推進及乙烯合成能力增546藝報31卷強而增加?？梢?乙烯受體基因在各種果實中可能存在不同的表達和調(diào)節(jié)模式。2.5果實乙烯受體基因表達 的調(diào)節(jié)2.5.1受體基因表達的調(diào)節(jié)途徑 果實乙烯受體基因的表達受發(fā)育成熟度及果實部位、乙烯、乙烯受體抑制劑等因素調(diào)節(jié)。魏紹沖等(57)對不同成熟時期番茄果實不同部位的LeETR4表達模式研究表明,LeETR4在番茄外果皮中的表達水平明顯低于果實的輻射壁和中柱部位。乙烯對各乙烯受體基因表達的影響不一,已在前述番茄果實的基因表達部分中提及。乙烯作用抑制劑與乙烯競爭受體結(jié)合位點，阻止組織對乙烯響應(yīng),其對果實中各乙烯受體基因的表達影響不同。Nakatsuka 等[58)用1 -甲基環(huán)丙烯( 1-MCP )處理轉(zhuǎn)色期番茄果實,發(fā)現(xiàn)果實中NR mRNA累積受阻,果實成熟推遲,而另一-受體基因eTAE1 ( LeETR1 )的表達基本沒有改變; 1-MCP處理對桃果實的Pp-ETR1表達沒有影響,但對Pp-ERS1表達起到抑制作用49)。2.5.2調(diào)節(jié)乙烯受體基因表達的基因工程通過調(diào)節(jié)乙烯受體基因的表達水平調(diào)控果實的成熟衰老進程,是實現(xiàn)生物技術(shù)延緩果實后熟軟化的一個重要途徑。目前,番茄乙烯受體的多種轉(zhuǎn)基因植株已獲得成功,但在其它果實中未見成功的報道。Wilkinson 等' 59)將擬南芥乙烯受體基因ETR1-1突變序列轉(zhuǎn)入番茄中,發(fā)現(xiàn)能明顯推遲果實后熟及花的衰老。Ciardi等'60)通過連接組成型表達的35S啟動子的NR eDNA獲得過量表達NR的轉(zhuǎn)基因植株對乙烯敏感性降低(61]。這些結(jié)果與擬南芥中的研究結(jié)果完全吻合,表明乙烯受體系統(tǒng)存在-定程度過剩。但是減少LeETR4的表達對植株影響嚴重,呈現(xiàn)出乙烯組成型反應(yīng),表現(xiàn)在葉偏上性,花瓣脫落和果實成熟提前等'61。而當這些影響發(fā)生時,乙烯生成并沒有增加,說明這些反應(yīng)與乙烯受體表達水平發(fā)生改變有關(guān)。轉(zhuǎn)基因植物中受體基因表達的研究揭示了乙烯受體之間可能存在功能補償( functional compensation ),當反義控制NR的表達后, LeETR4的表達則相應(yīng)提高,植株通過某種方式增加LeETR4的表達以補償NR表達的降低,因此NR反義植株整體的乙烯受體水平并未受明顯影響。Whitelaw 等62采用反義手段抑制番茄LeETR1的表達后,研究表明反義植株的葉片中NR表達水平以及果實的著色和硬度基本未受影響,但植株的節(jié)間變短,花的衰老延遲。Hackett 等(63)反義抑制了Nr突變體植株中的NR基因表達后, 果實恢復(fù)了成熟能力,這在證明乙烯受體是負調(diào)控的同時,也表明NR可能并不是果實正常成熟所必需的?？傊?，這些轉(zhuǎn)基因研究結(jié)果將有助于我們更正確地認識各個番茄乙烯受體基因的功能以及它們之間的相互關(guān)系。3展望乙烯的生理作用最終是通過乙烯受體及其信號轉(zhuǎn)導(dǎo)過程完成的。目前,番茄乙烯受體研究已經(jīng)較為深入,借助番茄乙烯受體的研究成果繼續(xù)開展其它果實乙烯受體的研究將是今后乙烯作用研究的一個新熱點。隨著果實成熟生理及乙烯受體研究的深入,相信從乙烯受體水平上調(diào)控果實成熟進程的基因工程不久將會應(yīng)用于生產(chǎn)實踐,并可望產(chǎn)生巨大的經(jīng)濟和社會效益。此外,乙烯的作用并不是獨立的,還需要其它激素的配合,因此要全面了解乙烯的作用,需要從分子生物學(xué)水平上對植物生長發(fā)育過程中乙烯與其它植物激素的關(guān)系,特別是結(jié)合信號轉(zhuǎn)導(dǎo)開展研究。目前許多學(xué)者已開始致力研究ABA與乙烯信號轉(zhuǎn)導(dǎo)的關(guān)系(64,65)。隨著21世紀蛋白質(zhì)組學(xué)時代的到來,乙烯受體及信號轉(zhuǎn)導(dǎo)在果實發(fā)育等過程中蛋白水平的變化及其互作,如乙烯受體與CTR的相互作用等,將是未來研究的一個重要方向。中國煤化工參考文獻:MHCNMHG1 Abeles F B , MorganP W，Saltveit Jr M E. Ethylene in plant biology. 2nd edn. New York : Academic Press , 1992. 182 ~2212 O' Donnell PJ , Calvert C , Azom R , et al. Ethylene as a signal mediating the wound response of tomato. Plant Sci. , 1996 , 274 : 1914~ 1917Boller T. Ethylene in pathogenesis and disease resistance. In : Mattoo A K , Suttle J C eds. The plant hormone ethylene. Boca Raton ,Florida: CRC Press, 1991. 293 ~314Bradford k個附振as A. Sensitivity thresholds and variable time scales in plant hormone action. Plant Physiol. , 1994 , 105 : 1029 ~ 10363期魏紹沖等:乙烯受體與果實成熟調(diào)控5475 Hoeberichts F A , Van Der PlasL H W , Woltering E J. Ethylene perception is required for the expression of tomato ripening-related genes andassociated physiological changes even at advanced stages of ripening. Postharvest Biol. Technol. , 2002 ,26: 125 -1366 YuemingJ , Jiarnui F. Ethylene regulation of fruit ripening : molecular aspects. Plant Growth Regul. ,2000 ,30 :193 -2007 Bary CS ,Llop-Tous M I ,Grierson D. The regulation of 1-aminocyclopropane-1 -carboxylic acid synthase gene expression during the transtionfrom system-1 to system-2 ethylene synthesis in tomato. Plant Physiol. ,2000 , 123 :979 ~986Llop-Tous I , Barry C S , Grierson D. Regulation of ethylene biosynthesis in response to pollination in tomato flowers. Plant Physiol. ,2000 ,123 :971 ~9789 Bleecker A B , Kende H. Ethylene : a gaseous signal molecule in plants. Annu. Rev. Cell. Dew. Biol. ,2000 ,16 :13 ~1810 Chang C , Stadler R. Ethylene hormone receptor action in Arabidopsis. Bioessays ,2001 ,23 :619 ~62711 Stepanova A N , Ecker J R. Ethylene signaling : from mutants to molecules. Cur. Opin. Plant Biol. , 2000 ,3 :353 ~ 36012 Kieber JJ ,Rothenberg M , Roman G ,et al. CTR1 ,a negative regulator of the ethylene response pathway in Arabidopsis , encodes a memberof the Raf family of protein kinases. Cell , 1993 ,72 :427 ~4413 AlonsoJ M , Hirayama T , Roman G ,et al. EIN2 , a bifunctional transducer of ethylene and stress responses in Arabidopsis Science ,1999 ,284 :2148 ~215214 Chao Q , Rothenberg M , Solano R , et al. Activation of the ethylene gas response pathway in Arabidopsis by the nuclear protein THYLENEIN-SENSITIVE3 and related proteins. Cell ,1997 ,89 :1133~ 114415 Solano R ,Stepanova A , Chao Q M ,et al. Nuclear events in ethylene signaling : a transduction cascade mediated by ETHYLENE-INSENSI-TIVE3 and ETHYLENERESPONSE-FACTORI. Genes Devel. ,1998 ,12 :3703 ~371416 Chang C ,Kwok S F , Bleecker A B ,et al. Arabidopsis ethylene-response gene ETR1 : similarity of product to two-comopnent regulators. Sci-ence , 1993 ,262 :539 ~ 54417 Giovannoni J. Molecular biology of fruit maturation and ripening. Annu. Rev. Plant Physiol. Plant Mol. Biol. , 2001 ,52 :725 ~7498 Chen Y F , Randlett M D , Findell JL , et al. Localization of the ethylene receptor ETR1 to the endoplasmie reticulum of Arabidopsis. J. Biol.Chem. ,2002 ,277 : 19861 ~ 1986619 Stock A M ,Robinson V L , Goudreau P N. Two-component signal transduction. Annu. Rev. Biochem. ,2000 ,69 :183 ~21520 Schaller G E , Beecker A B. Ethylene-binding sites generated in yeast expressing the Arabidopsis ETRI gene. Science ,1995 ,270 :1809~ 181121 SchallerG E , Ladd A N , Lanahan M B ,et al. The ethylene response mediator ETRI from Arabidopsis forms a disufide-linked dimer. J. Biol. Chem. ,1995 ,270 :12526 ~ 1253022 Hirayama T , AlonsoJ M. Ethylene captures a melal !Metal ions are involved in ethylene perception and signal transduction. Plant Cell Physi-ol. ,2000 ,41 :548 ~55523 RodriguezF I ,EschJJ ,Hall A E ,et al. A copper cofactor for the ethylene receptor ETRI from Arabidopsis. Science ,1999 ,283 :996 -99824 HuaJ ,ChangC , Sun Q ,et al. Ethylene insensitivity conferred by Arabidopsis ERS gene. Science ,1995 ,269 :1712 ~171425 HuaJ , Sakai H , NourizadehS ,et al. EIN4 and ERS2 are members of the putative ethylene receptor gene family in Arabidopsis. Plant Cell ,1998 ,10 :1321 ~ 133226 Sakai H ,HuaJ ,ChenQG ,et al. Meyerowitz EM ETR2 is an ETRI .like gene involved in ethylene signaling in Arabidopsis. Proc. Natl.Acad. Sci. USA , 1998 ,95 :5812 -581727 Ciardi J , Klee H. Regulation of ethylene -mediated responses at the level of the receptor. Ann. Bot. ,2001 , 88 :813 ~ 82228 Gamble R L ,Coonfield M L , Schaller G E. Histidine kinase activity of the ETRI ethylene receptor from Arabidopsis. Proc. Natl. Acad. Sei.USA ,1998 ,95 :7825 -782929 HuaJ ,Meyerovitz E M. Ethylene responses are negatively regulated by a receptor gene fanily in Arabidopsis thaliana. Cell ,1998 ,94 :261 ~271 .30 WilkinsonJ ,Lanahan M , Yen H ,et al. An ethylene-inducible component of signal transduction encoded by Never-ripe. Science , 1995 ,270 :1807 ~ 180931 Zhou D B , Kalaitzis P MattooA K ,et al. The mRNA for an ETRI homologue in tomato is costitutively expressed in vegtative and repro-ductive tssues. Plant Mol. Biol. , 1996 ,30 :1331 ~ 133832 Zhou D , Matto A K ,Tucker M L. Molecular cloning of a tomato cDNA enc中國煤化工d. ,196 ,10:45 -143633 PaytonS ,Fray R G , Brown s ,et al. Ethylene receptor expression is regul:YHC N M H Gnescence and absission. PlantMol. Biol. , 1996 ,31 :1227 ~ 123134 Lashbrook C C , Tieman D M , Klee H J. Differential regulation of the tomato ETR gene family throughout plant development. Plant J. ,1998 ,15 :243 ~ 25235 Tieman D M。Klee H J. Diferential expression of two novel members of the tomato ethylene-receptor farily. Plant Physiol. , 199 ,120 :165 ~17236 Klee H tin齊撈M. The tonato ethylene receptor gene family : Form and function. Physiol. Plant ,2002 ,115 :336 ~ 341548園藝報31卷37 Lanahan M B , Yen H C , Giovannoni J J ,et al. The Never ripe mutation blocks ethylene perception in tomato. Plant Cell ,1994 ,6 :521 ~ 53038 Klee H J. Control of ethylene mediated processes in tomato at the level of recepors. J. Exp. Bot. ,2002 ,53 :2057 -206339 Ostin A , Kowalyczk M , Bhalerao R P , et al. Metabolism of indole-3-acetic acid in Arabidopsis. Plant Physiol. ,1998 ,118 :285 ~ 29640 LinZ , Hackett R M ,Payton s ,et al. A tomato sequence encoding an Arabidopsis CTR1 homologue. Plant Physiol. ,1998 ,117 :112541 Zegzouti H ,Jones B , Frasse P ,et al. Ethylene -regulated gene expression in tomato fruit : charaterizaion of novel ethylene-responsive andripening- related genes isolated by differential display. Plant J. ,1999 ,18 :589 ~ 60042 Alexander L ,Grierson D. Ethylene biosynthesis and action in tomato :a model for climacteric fruit ripening. J. Exp. Bot. ,2002 ,53 :2039 ~205543 Gu Y Q ,YangC ,TharaV K ,et al. Pri4 is induced by ethylene and saliceylic acid , and is product is phosphorylated by the Plokinase. PlantCell ,2000 ,12 :771 -78514 Tieman D M ,Taylor MG ,Giardi. J A ,et al. Members of the tomato LeEIL ( EIN3-like ) gene family are functionally redundant and regulateethylene responses throughout plant development. Plant J. ,2001 ,26 :47 ~5845 Sato-Nara K , Yuhashi K 1 ,Higashi K ,et al. Stage- and tseific expression of ethylene receptor homolog genes during fruit developmentin muskmelon. Plant Physiol. ,1999 ,120 :321 ~32946 Mita S , Kawamura S , Yamawaki K ,et al. Differential expression of genes involved in the biosynthesis and perception of ethylene during ripe-ning of passion fruit ( Pasifora edulis Sims ). Plant Cell Physiol. , 1998 ,39 :1209 ~ 121747 Mita S , KawarmuraS , Asai T. Regulation of the expression of a putative ethylene receptor , PeERS2 , during the development of passion fruit( Psiflora edulis). Plhysiol. Plant ,2002 ,114 :271 -28048 Bassett C L , Artlip T S. Isolation of an ETRI ethylene receptor homologue from peach [ Prunus persica( L. ) Batsch]. HortSci. , 1999 ,34 :54249 Rasori. A , Ruperti B , Bonghi C ,et al. Characterization of two putative ethylene receptor genes expressed during peach fruit development andabscision. J. Exp. Bot. ,2002 ,53 :2333 ~233950 Wu HT,Do Y Y , Huang P L. Nucleotide sequence of a eDNA encoding ethylene reeptor from banana fruits. Plant Physiol. ,1999 ,119 :80551 Martinez R L , G6mez M A. Gomez. _Lim ldentification of an ETRI-homologue from mango fruit expressing during fruit ripening and wounding.J. Plant Physiol. ,2001 , 158 :101 ~ 10852 LeeS A ,Ross GS , Gardner R C. An apple ( Malus domestica L. Borkh ev. Granny Smith ) homolog of the ethylene receptor gene ETR1.Plant Physiol. ,1998 ,117 :112553 李正國, El-Sharkaw , Lelievre J~M.溫度、丙稀和1 - MCP對西洋梨果實乙烯合成和乙烯受體ETR1同源基因表達的影響.園藝學(xué)報,2000 ,27 :313-31654 EI-Sharkawy I , Jones B ,LiZG ,et al. Isolation and characterization of four ethylene perception elements and their expression during ripeningin pears ( Pyrus communis L. ) with/without cold requirement. J. Exp. Bot. ,2003 ,54 :1615 ~ 162555 Li C ,Jacob-Wilk D , Zhong G ,et al. A Full-length cDNA encoding an ethylene receptor ERS homologue from citrus. Plant Physiol. , 1998 ,118 :153456 Yamasaki S , Fujli N , Takahashi H. The ethylene-regulated expression of CS ETR2 and CS ERS genes in cucumber plants and their possibleinvolvement with sex expression in flowers. Plant Cell Physiol. ,2000 ,41 :608 ~61657 魏紹沖,朱本忠,羅云波，等.乙烯受體基因LeETRI和LeETR4的克隆及在番茄果實中的表達.農(nóng)業(yè)生物技術(shù)學(xué)報,2003 ,10:167 ~ 17058 Nakatsuka A , Murachi S , Okunishi H ,et al. Differential expression and interal feedback regulation of 1-aminocylopropane-1 -carboxylatesynthase , I-aminocyclopropane-I -carboxylate oxidase , and ethylenereceptor genes in tomato fruit during development and ripening. PlantPhysiol. , 1998 ,118 : 1295 ~ 130559 Wilkinson JQ ,Lanahan M B ,Clark DG ,et al. A dominant mutation receptor from Arabidopsis confers ethylene insensitivity in heterologousplants. Nature Biotech. ,1997 ,15 :444 ~44760 CiardiJ A ,Tieman D M ,LundS T ,et al. Response to Xanthomonas campestris pv. vesicatoria in tomato involves regulation of ethylene re-ceptor gene expression. Plant Physiol. ,2000 ,123 :81 -9261 Tieman D M ,Taylor M G ,CiardiJ A ,et al. The tomato ethylene receptors NR and LeETR4 are negative regulators of ethylene response andexhibit functional compensation within a muligene family. Proc. Natl.中國煤化工566862 Whitelaw C A , Iyssenko N N ,Chen L ,et al. Delayed absisions and sh:IYHc N M H Guction in lhe ehylene reporLeETR1 transcript in transgenic tomato. Plant Physiol. ,2002 , 128 :97863 Hackett R M ,HoC W ,LinZF ,et al. Antisense inhibition of the Nr gene restores normal ripening to the tomato Never-ipe mutant ,consist-ent with the ethylene receptor inhibition model. Plant Physiol. ,2000 , 124 :1079 ~ 108564 Gazarini S , McCourt P. Genetic interactions betwen ABA ,elhylene and sugar signaling pahways. Cur. Opin. Plant Biol. ,2001 ,4 :387 -~39165 BeaudoinC , Gosti F ,et al. Interactions between abscisic acid and ethylene signaling cascades. Plant Cell ,2000 ,12 :1103 -1115