陳娜 邵勤 李曉鵬
摘要:WRKY轉錄因子是近20多年來發(fā)現的植物特有的最大的轉錄因子家族之一。WRKY的名稱來源于基因中最顯著的氨基酸序列特征WRKY結構域。WRKY結構域是一個高度保守的區(qū)域,由60個氨基酸組成,在其N端有1個保守的七肽段WRKYGQK,然后是1個分子式為C2H2或C2HC的鋅指基序。目的基因中保守的WRKY結構域同源結合位點稱為W box(C/TTGACT/C),幾乎所有WRKY轉錄因子都優(yōu)先結合該位點。越來越多的研究證實,WRKY轉錄因子在植物生長發(fā)育過程中扮演著重要角色。本文簡要介紹了WRKY轉錄因子家族的分子結構特征及分類,并綜述了番茄WRKY轉錄因子在響應生物與非生物逆境脅迫、調控生長發(fā)育、激素信號轉導等方面的生物學功能,以期為進一步研究番茄 WRKY基因家族的調控機制提供理論基礎與研究思路。
關鍵詞:番茄;WRKY轉錄因子;生物和非生物脅迫;生長發(fā)育;激素信號轉導
中圖分類號:S641.201? 文獻標志碼:A
文章編號:1002-1302(2023)13-0006-11
番茄(Solanum lycopersicum L.)是茄科茄屬一年生或多年生草本植物,原產于墨西哥,是世界上最重要的蔬菜作物之一,也是中國北方、南方普遍栽培的重要蔬菜[1-2]。2019年全球產量超過1.8×108 t,收獲面積略高于5×106 hm2。1999—2019年,全球番茄收獲面積增加了27%,產量增加了66%[3]。番茄富含維生素A、維生素C和維生素E,還含有大量水及鈣、煙酸等營養(yǎng)物質[4],這些營養(yǎng)物質可以降低患癌癥、心血管疾病和骨質疏松病的風險[5-6]。由此可見,番茄是一種重要的高營養(yǎng)蔬菜作物。
植物可以在復雜環(huán)境中調節(jié)自身的代謝和生長發(fā)育過程,而在這些生長發(fā)育過程往往會受到轉錄因子的調控。有研究證實,bZIP、NAC、MYB、WRKY和其他轉錄因子家族在植物生長發(fā)育過程中發(fā)揮著重要作用,參與了各種脅迫應答響應過程[7-8]。WRKY轉錄因子廣泛分布于陸生植物中,是植物中最大的特異轉錄因子家族之一,它們具有多種生物學功能,包括參與植物生長發(fā)育、非生物和生物脅迫的響應過程、植物次生生長和植物激素信號轉導過程等[9-13]。第1個WRKY基因是從甘薯(Ipomoea batatas)中分離得到的[14],隨著植物(特別是模式植物)全基因組測序工作的推進,更多WRKY基因得到鑒定,其中大豆(Glycine max)中有182個WRKY轉錄因子被發(fā)現[15],小麥(Triticum aestivum)中有171個WRKY基因被發(fā)現[16],玉米(Zea may)中有120個WRKY基因被發(fā)現[17],水稻(Oryza sativa)中有103個WRKY基因被發(fā)現[18],馬鈴薯(Solanum tuberosum)中有79個WRKY基因被發(fā)現[19],擬南芥(Arabidopsis thaliana)有72個WRKY基因被發(fā)現[20],黃瓜(Cucumis sativus)中有57個WRKY基因被發(fā)現[21],油菜(Brassica napus)中有46個WRKY基因被發(fā)現[22]。隨著番茄全基因組序列的公布,Huang等在番茄中鑒定到81個WRKY轉錄因子,此外,有研究發(fā)現,番茄WRKY基因在不同發(fā)育過程中及對各種生物、非生物脅迫的響應過程中表現出不同的時空表達模式[23-24]。
1 植物WRKY轉錄因子的結構和分類
WRKY結構域是WRKY轉錄因子最顯著的結構特征,該結構域在其N末端有1個高度保守的WRKYGQK七肽序列,在其C末端有1個鋅指基序,該鋅指基序可以是C2H2型(CX4~5CX22~23HXH),也可以是C2HC型(CX7CX23HXC)[25-26]。根據WRKY結構域的數量和鋅指基序的類型,WRKY蛋白可分為3種系統發(fā)育不同的族:GroupⅠ的WRKY蛋白包含2個WRKY結構域和1個CX4~5CX22~23HXH鋅指基序;GroupⅡ的WRKY蛋白包含1個WRKY結構域和1個CX4-5CX22-23HXH鋅指基序;Group Ⅲ的WRKY蛋白包含1個WRKY結構域和1個CX7CX23HXC鋅指基序。此外,通過系統發(fā)育分析發(fā)現,GroupⅡ的WRKY蛋白又可分為5個亞類:GroupⅡa、GroupⅡb、GroupⅡc、GroupⅡd和GroupⅡe[25-28]。
Huang等報道,番茄中有81個WRKY轉錄因子,并且除了第11號染色體,其他11條染色體中均有WRKY轉錄因子的分布[23-24]。其中5號染色體上分布的WRKY轉錄因子最多,有16個,而9號染色體上分布的WRKY轉錄因子最少,僅有4個[23-24]。番茄的81個WRKY轉錄因子中有15個成員屬于GroupⅠ,55個成員屬于GroupⅡ,這55個成員中又細分為GroupⅡa、GroupⅡb、GroupⅡc、GroupⅡd和GroupⅡe,分別有6、9、17、6、8個成員,最后9個成員屬于Group Ⅲ[24]。
2 番茄WRKY轉錄因子的生物學功能
有研究發(fā)現,番茄WRKY轉錄因子參與了植物生長發(fā)育、生物與非生物逆境脅迫及激素信號轉導過程,但是只有少數WRKY基因功能被驗證,絕大多數基因功能還尚待研究。下文綜述了番茄 WRKY家族相關基因在植物生長發(fā)育、生物和非生物逆境下及激素信號轉導過程的研究進展。
2.1 番茄WRKY轉錄因子參與了植物的生長發(fā)育過程
大量基因的有序表達構成了控制植物生長發(fā)育的基礎,其中轉錄因子充當協調基因表達的“開關”。WRKY轉錄因子在植物生長發(fā)育中發(fā)揮著重要作用[29-32]。此外,WRKY轉錄因子也參與了番茄植株的生長發(fā)育。Spyropoulou等報道,番茄SlWRKY78在葉片、毛狀體、根和花中表達,SlWRKY28是毛狀體的特異性基因,SlWRKY73在毛狀體、根和果實中表達,并參與調控萜烯生物合成的過程[33]。Li等發(fā)現,沉默SlWRKY17延遲了弱光誘導的花脫落,并且能夠與SlIDL6的啟動子結合[34]。Singh等從番茄中鑒定到1個主要在根中表達的WRKY轉錄因子SlWRKY23,通過研究發(fā)現,轉SlWRKY23基因植株的葉片數量更多,但蓮座更小。轉基因株系的開花時間縮短了,這些植株也顯示出更多的花序分枝、角果和種子。此外,這些植物的角果較長,并緊密充滿種子,但種子在尺寸上較小。與對照相比,轉SlWRKY23基因擬南芥在收獲時的根系生物量下降了25%。有研究表明,SlWRKY23在植物生長調控中扮演著重要角色[35]。
葉片衰老是植物一個重要的生理過程,它可以支持氮和其他營養(yǎng)物質的循環(huán)利用,促進包括種子、葉片和果實在內的新器官的生長發(fā)育。由此可見,調控植物衰老對野生種群的適合度和提高作物產量具有重要意義。WRKY轉錄因子已被證實參與到植物的衰老過程中[36-39]。有研究發(fā)現,一些WRKY轉錄因子參與了番茄葉片的衰老過程。王璐通過研究發(fā)現,番茄WRKY轉錄因子SlWRKY16/17/22/23/25/31/33/53/54在番茄葉片中的表達量變化趨勢與葉片的成熟度呈正相關,在葉片進入衰老狀態(tài)時表達量最高,表明上述SlWRKY可能與葉片衰老相關[40]。Wang等報道,茉莉酸甲酯(methyl jasmonate,MeJA)和暗處理(dark)均顯著誘導了茉莉酸(jasmonic,acid,JA)信號中番茄SlWRKY37和SlMYC2基因的表達水平。SlMYC2直接結合到SlWRKY37的啟動子上,激活其表達。敲除SlWRKY37可以抑制JA、dark誘導的葉片衰老。轉錄組分析和生化試驗結果表明,SlWRKY53和SlSGR1 (S. lycopersicum衰老誘導葉綠體保持綠色蛋白1)是SlWRKY37調控葉片衰老的直接轉錄靶點。此外,SlWRKY37與含有VQ基序的蛋白SlVQ7互作,該互作促進了SlWRKY37蛋白的穩(wěn)定性和下游靶基因的轉錄激活。研究結果揭示了SlWRKY37在葉片衰老過程中的生理和分子功能,并提供了1個靶基因,通過降低JA、dark等外部衰老信號的敏感性來延緩葉片黃化[41]。
WRKY轉錄因子也參與調控植物果實的成熟[42-44]。賈寧通過研究得出,番茄WRKY轉錄因子SlWRKY16/17/53/54基因與番茄后熟過程緊密相關,同時SlWRKY17/53基因受到后熟重要轉錄因子的調控,參與后熟調控過程并起重要作用[45]。Liu等對紫番茄靛藍玫瑰的果皮、果肉進行了轉錄組比較分析,發(fā)現2個與花青素相關的WRKY基因(SlWRKY53和SlWRKY54)僅在成熟綠色階段的果皮和果肉之間存在顯著差異表達[46]。王璐通過研究發(fā)現,番茄SlWRKY16/17/22/23/25/31/33/53/54在番茄果實成熟過程中具有一定的時序性表達特性,但都在后熟階段顯著上調表達。進一步研究發(fā)現,WRKY 轉錄因子可能從多個途徑(葉綠素降解、番茄紅素合成、果實成熟衰老相關的轉錄因子ERF/RIN等)參與番茄果實成熟衰老的調控[40]。Yuan等報道,SlWRKY35為番茄中類胡蘿卜素生物合成的正調控因子。進一步研究得出,SlWRKY35可直接激活1-脫氧-D-木酮糖5-磷酸合酶(SlDXS1)基因的表達,將代謝重編程為2-C-甲基-D-赤蘚糖醇4-磷酸(MEP)途徑,從而增強類胡蘿卜素的積累。主調節(jié)因子SlRIN在番茄果實成熟過程中直接調節(jié)SlWRKY35的表達。與SlLCYE過表達系相比,SlWRKY35和SlLCYE的共表達可以進一步提高轉基因番茄果實中葉黃素的產生量。以上研究結果表明,SlWRKY35通過正向調控MEP途徑衍生的過程,如葉綠素、類胡蘿卜素的生物合成進而參與番茄代謝的新型調節(jié)因子[47]。Arhondakis等從番茄中鑒定到1個WRKY轉錄因子SlWRKY22-like,通過研究發(fā)現,SlWRKY22-like可能參與了6種鈣傳感基因表達的協調調控,從而調控番茄果實成熟[48]。Wang等從23個番茄SlWRKYs(這些基因是與其他植物響應乙烯相似或在果實成熟期間顯示上調的WRKY基因)中發(fā)現12個SlWRKYs在果實成熟過程中被乙烯處理上調表達,因此被命名為SlER-WRKYs。通過進一步研究得出,12個SlER-WRKYs中有8個可能直接調節(jié)與顏色變化相關的4個基因(SlPAO、SlPPH、SlPSY1和SlPDS)。以上研究結果表明,WRKY轉錄因子在果實成熟過程中起作用,特別是在顏色變化中起作用,并且與其他成熟調控因子的復雜調控網絡相關[49]。
以上研究結果表明,番茄WRKY轉錄因子參與了植物的生長發(fā)育過程,主要涉及根系生長、植株開花、葉片衰老及果實成熟等一系列過程,但相關研究較少,在生長發(fā)育的其他方面,如種子發(fā)育、次生壁形成等方面的研究仍是空白,因此其他番茄WRKY基因的功能仍有待探究,后續(xù)應開展番茄WRKY轉錄因子在調控植物生長發(fā)育方面作用的研究。
2.2 番茄WRKY轉錄因子參與非生物脅迫的響應過程
植物在其生長發(fā)育過程中經常受到高/低溫、鹽、干旱等非生物脅迫,這就要求植物在生理上適應和抵抗一系列條件。植物基因表達變化、信號轉導過程、生理生化變化等響應機制是一個復雜的過程,WRKY轉錄因子在這些過程中發(fā)揮著重要作用。近年來,越來越多的WRKY轉錄因子被研究,重點是它們在非生物脅迫響應中的調控作用[50-56]。許多研究也探討了WRKY基因在番茄植物非生物脅迫中的作用,其中鹽、干旱是影響番茄植株生長發(fā)育的主要非生物脅迫因素,番茄SlWRKY53、SlWRKY23、SlWRKY1、SlWRKY3、SlWRKY44、SlWRKY39、WRKY12和WRKY13、SlWRKY4、SlWRKY81被報道在植株抵抗鹽、干旱脅迫的響應中具有重要作用[57-67]。例如,孫曉春等用鹽脅迫處理3個獨立的轉SlWRKY23基因株系(WRKY23-1、WRKY23-5和WRKY23-7)后發(fā)現,轉基因植株表現出明顯的抗鹽表型,同時逆性相關基因SlRD22、SlDREB2A的表達量顯著高于野生型。該結果表明,SlWRKY23基因在番茄抗鹽脅迫過程中具有正調控作用,并通過上調逆性相關基因的表達量來增強番茄植株的抗逆性[58]。張凝等通過克隆得到番茄SlWRKY1基因,通過研究發(fā)現,過表達SlWRKY1植株對鹽脅迫表現出抗逆性,在脅迫條件下,轉基因植物中積累了大量脯氨酸(proline,Pro),推測SlWRKY1基因可能通過參與番茄Pro代謝調控過程從而調控植株對鹽脅迫的抗性[59]。Birhanu等通過研究發(fā)現,番茄WRKY12、WRKY13在番茄耐鹽脅迫中起負調控作用。SOS1在WRKY13_RNAi中上調,可能導致低Na+積累并有助于耐鹽性。APX在WRKY12和WRKY13_RNAi中的表達量上調,可能有助于這2種基因型的耐鹽機制[64]。Ahammed等通過研究得出,番茄SlWRKY81通過抑制SlRBOH1衍生的過氧化氫(hydrogen peroxide,H2O2)積累量來負調控氣孔關閉,從而減弱植物對干旱的耐受性。進一步研究得出,干旱誘導了SlWRKY81的表達并降低了植物的光合能力。并通過光學顯微鏡、生化分析和共聚焦激光掃描顯微鏡等研究發(fā)現,SlWRKY81可能通過抑制硝酸還原酶(nitrate reductase,NR)編碼的NR基因的轉錄來抑制保衛(wèi)細胞中一氧化氮(nitric oxide,NO)的積累以應對干旱,從而最終抑制氣孔關閉并減弱番茄的耐旱性[66-67]。
高/低溫也是番茄生長發(fā)育過程中的主要脅迫因素,在很大程度上影響了番茄的品質和產量。Zhou等通過研究發(fā)現,沉默番茄WRKY33基因降低了番茄的耐熱性,降低了熱誘導自噬相關基因(autophagy-related gene,ATG)的表達量和自噬小體的積累量[68]。Chen等從番茄基因組中鑒定出80個WRKY基因,轉錄分析結果顯示,番茄中有10個WRKY在低溫脅迫下被強烈誘導2倍以上。該結果能為以后深入研究番茄WRKY轉錄因子調控冷脅迫的分子機制奠定基礎[69]。Zhou等通過分子互補和基因沉默試驗證實,番茄2個WRKY基因(SlWRKY33A和SlWRKY33B)在植物對耐熱的脅迫響應中發(fā)揮了關鍵作用[70]。王夢琪通過研究發(fā)現,番茄WRKY6參與了番茄調控低溫抗性的過程[71]。王藝璇等通過研究發(fā)現,番茄81個WRKY轉錄因子中有27個能夠被低溫顯著誘導,進一步研究推測,轉錄因子可能參與了CBFs (C-repeat binding factors)介導的低溫響應途徑[72]。周靖翔從番茄中篩選到1個冷應激反應過程中的關鍵抗冷因子SlWRKY45,并通過病毒誘導的基因沉默(virus-induced gene silencing,VIGS)技術沉默該基因,使得番茄果實的冷害癥狀加重,初步表明SlWRKY45在番茄果實的冷害中起著一定作用[73]。此外Guo等研究發(fā)現,番茄WRKY33與冷敏感性相關[74]。
另外,Ye等通過研究發(fā)現,SlWRKY42負調控番茄果實的蘋果酸含量和鋁(Al)抗逆性[75]。Wang等通過研究發(fā)現,6個SlWRKY基因(SlWRKY3、SlWRKY6、SlWRKY16、SlWRKY37、SlWRKY39和SlWRKY71)可能參與了JA對鋁脅迫下番茄根系生長抑制的調控[76]。王茹等利用RT-PCR技術從番茄中克隆得到1個WRKY轉錄因子SlWRKY6,通過實時熒光定量 PCR分析得出,SlWRKY6基因的表達量在3種重金屬(CdCl2、CuCl2、HgSO4)脅迫下均上調,研究結果可為篩選番茄中響應重金屬脅迫功能基因的研究提供基礎[77]。以上研究結果表明,番茄WRKY轉錄因子在響應鋁、重金屬方面也有重要作用。
除此之外,番茄WRKY轉錄因子在鹽與干旱、鹽與低溫、干旱、鹽和寒冷等復合脅迫的響應過程中也扮演著重要角色[78-87]。例如,Li等利用同源克隆法從番茄中分離到SlWRKY基因,半定量 RT-PCR 分析結果表明,鹽和干旱處理能夠誘導SlWRKY的表達量上調。在煙草中過表達該基因,會使轉基因植株比野生型植株生長得旺盛,并通過提高抗氧化酶活性,降低電導率(EC)和丙二醛(malondialdehyde,MDA)含量,降低氧化損傷,從而使轉基因植株對鹽、干旱脅迫的耐受性提高。此外,Li等觀察到SlWRKY蛋白能夠調控下游基因,增加防御相關PR1、PR2基因的表達量[79]。Li等報道,鹽和干旱均能誘導番茄SpWRKY1基因的表達,在煙草中過表達SpWRKY1能夠顯著提高植株對鹽、干旱脅迫的耐受性。進一步研究發(fā)現,SpWRKY1可通過提高防御酶的活性、促進滲透調節(jié)物質的積累、調節(jié)相關信號途徑及抗性基因的表達,以正向調控方式參與番茄的防衛(wèi)反應[80-81]。Gao等報道,番茄SlWRKY8能夠被干旱、鹽和寒冷等非生物脅迫誘導,過表達SlWRKY8的轉基因植物在干旱、鹽脅迫下表現出較輕的萎蔫或褪綠表型,具有更高水平的脅迫誘導的滲透物質(如Pro)和更高的脅迫響應基因SlAREB、SlDREB2A和SlRD29的轉錄水平。與野生型植株相比,轉基因植物在干旱脅迫下的氣孔孔徑較小,葉片中的水分含量較高。此外,用H2O2和MDA濃度表示的氧化壓力在轉基因植物中也降低了,在脅迫下的抗氧化酶活性更高,表明SlWRKY8在植物對干旱和鹽脅迫的響應中起著正調控的作用[87]。
以上研究結果表明,影響番茄的主要非生物脅迫因素有干旱、鹽堿、高/低溫、水分虧缺、冷害、重金屬等,而番茄WRKY轉錄因子調控這些非生物脅迫的作用機制還有待深入解析,因此,關于番茄的相關研究工作還有待深入。
2.3 番茄WRKY轉錄因子參與生物脅迫的響應過程
除了各種非生物脅迫,在整個生命周期中,植物還經常受到病原體的攻擊,如細菌、真菌和病毒。因此,植物在長期進化過程中逐漸形成了復雜的抗病機制,而WRKY轉錄因子在這些機制中發(fā)揮著重要作用[88-94]。關于番茄WRKY轉錄因子參與生物脅迫抗性的研究也有報道。有研究發(fā)現,番茄LeWRKY1、Sl-WRKY1、LeWRKY2、SlDRW1、SlWRKY33A和SlWRKY33B、SlWRKY3、SlWRKY46、SlWRKY31參與了植株對灰霉菌(Botrytis cinerea)抗性的響應過程[71,95-102]。孫清鵬等通過研究得出,番茄B. cinerea可以誘導LeWRKY2基因的表達,且在接種后4 h時其表達量達到最高值。用JA處理番茄幼苗后,LeWRKY2基因的相對含量在處理后 0~60 min與JA處理時間成正比;在處理后60~150 min 則與JA處理時間成反比,表明LeWRKY2是一種參與番茄防御反應的早期快速反應基因[97]。Liu等通過研究得出,B. cinerea能夠顯著誘導SlDRW1的表達,而假單胞桿菌(Pseudomonas syringae pv. tomato DC3000,Pst DC3000)不誘導SlDRW1的表達。沉默SlDRW1基因會導致B. cinerea的嚴重程度增加,但不影響Pst DC3000引起的病害表型。此外,SlDRW1的沉默也導致其對氧化脅迫的耐受性下降,但不影響其對干旱脅迫的耐受性。SlDRW1基因沉默后感染B. cinerea,引起防御相關基因的表達,從而減弱植株的防御反應。上述研究結果表明,SlDRW1是番茄抗B. cinerea和氧化脅迫防御反應的正向調節(jié)因子[98]。蔡俊通過對TPK1b(Tomato Protein Kinase 1b)啟動子的酵母單雜交釣庫試驗,篩選并鑒定到1個能夠負調控番茄對B. cinerea抗性的WRKY蛋白SlWRKY3,進一步對SlWRKY3的抗性調控機制進行初步解析,得出SlWRKY3能夠負調控TPK1b基因的表達,進而影響水楊酸(salicylic acid,SA)、ROS等信號,最終實現對番茄抗灰霉病抗性的調控[100]。Huang等研究發(fā)現,番茄中的SlJAZ相互作用蛋白SlVQ15與SlWRKY31相互作用,以協同、正向方式調控JA介導的番茄對B. cinerea的防衛(wèi)響應過程[102]。
孫曉春等對3個獨立的轉SlWRKY23株系(WRKY23-1、WRKY23-5和WRKY23-7)接Pst DC3000后發(fā)現,轉基因植株表現明顯的抗病表型,抗病防御相關基因SlPR1、SlPR1a1的表達量顯著高于野生型,從而推測番茄中的SlWRKY23基因可能通過上調防御相關基因的表達量來調控在番茄對Pst DC3000的抗性[58]。除了SlWRKY23轉錄因子,SlWRKY80、SlWRKY1、SlWRKY39、SlWRKY8、SlWRKY22和SlWRKY25也被證實參與了番茄調控Pst DC3000的抗性響應過程[59,87,103-105]。Sun等研究發(fā)現,番茄SlWRKY39可能通過激活致病相關基因SlPR1、SlPR1a1和脅迫相關基因SlRD22、SlDREB2A的表達來調控植株對Pst DC3000的抗性[104]。Gao等研究得出,過表達番茄SlWRKY8能夠增強植株對Pst DC3000的抗性,同時與病原相關的2個基因SlPR1a1、SlPR7的轉錄水平提高。上述結果表明,SlWRKY8可能通過調控病原相關基因的表達,從而在植物對病原體的防衛(wèi)響應中起到正調控作用[87]。
致病疫霉(Phytophthora infestans)也是番茄中比較重要的病害,前人研究發(fā)現,番茄SpWRKY2、WRKY1、SpWRKY6、SpWRKY3、SpWRKY6均是植株對P. infestans抗性響應的正調控因子[80-81,106-110]。如Cui等對接種、不接種P. infestans的番茄進行了轉錄組比較分析,發(fā)現SpWRKY3能夠被P. infestans顯著誘導,進一步研究發(fā)現,SpWRKY3能夠通過誘導PR基因的表達并減少活性氧(reactive oxygen,ROS)積累以防止細胞膜損傷,從而增強了植株對P. infestans的抗性[108]。Hong等用VIGS方法沉默番茄SpWRKY6,可以降低番茄對P. infestans的抗性。相比而言,過表達SpWRKY6的番茄植株對P. infestans的抗性增強,并伴有壞死細胞數量、病變大小和疾病指數的下降。此外,過表達SpWRKY6的轉基因番茄植株感染P. infestans后,其PR基因的表達量顯著高于野生型植株,而壞死細胞數量和ROS積累量較少且較低。上述研究結果表明,SpWRKY6通過調節(jié)ROS水平、PR基因的表達水平來減輕細胞膜損傷,是番茄抗P. infestans侵染的正向調控因子[109]。
除此之外,番茄WRKY基因(LpWRKY1、SlWRKY16、SlWRKY1/11/39/53/70、SlWRKY23、SaWRKY1、WRKY40與WRKY53、WRKY2229和WRKY33等)還被報道參與其他生物脅迫(如枯萎病、卷葉病、早疫病、青枯病等)的響應過程[60,111-119]。另外,Huang等從番茄中鑒定到6個能夠響應番茄黃葉卷曲病病毒(tomato yellow leaf curly virus,TYLCV)的WRKY轉錄因子(SolyWRKY41、SolyWRKY42、SolyWRKY53、SolyWRKY54、SolyWRKY80和SolyWRKY81),在SolyWRKY41和SolyWRKY54沉默后的抗性番茄葉片中,番茄TYLCV的含量顯著低于對照,表明SolyWRKY41和SolyWRKY54負調控番茄TYLCV的侵染。進一步研究發(fā)現,上述轉錄因子還可以通過與其他基因啟動子區(qū)域中存在的順式元件結合來與其他蛋白質相互作用,從而調節(jié)病原體相關基因的表達[120]。Aamir等通過全基因組計算分析發(fā)現,在番茄枯萎病病菌(Fusarium oxysporum f. sp. lycopersici,Fol)侵染期間,WRKY基因家族中有16個不同成員參與其中,其中只有4個WRKY基因(SolyWRKY4、SlWRKY31、SolyWRKY33和SolyWRKY37)的表達差異顯著,并伴隨著H2O2的產生和積累以及木質化組織的增強[121-122]。Gharsallah等研究發(fā)現,植株接種番茄黃化曲葉病(tomato yellow leaf curl disease,TYLCD)病毒后,抗病材料中SlWRKY8、SlWRKY31和SlWRKY39的表達水平均顯著上調,而在TYCLD和鹽聯合脅迫下的表達水平有所降低。進一步通過建立WRKY轉錄因子的相互作用網絡得出,SlWRKY39、SlWRKY8和SlWRKY33似乎是相互關聯的。此外,SlWRKY39、SlWRKY8與植物防御反應的正向調控因子MPK3 (絲裂原活化蛋白激酶)互作,SlWRKY31與MAPK7共表達。同時發(fā)現NAC1與SlWRKY31、SlWRKY39存在共同表達。值得注意的是,SlWRKY39和SlWRKY8似乎與CNGIC基因相互作用。CNGIC是1個環(huán)核苷酸門控離子通道1型基因,可能與環(huán)腺苷酸(cyclic adenosine monophosphate,camp)誘導的鈣進入細胞有關,是植物脅迫反應信號轉導的一部分。SlERF通過與其他蛋白質相互作用參與不同的功能途徑。SlERF16連接SlWRKY31和MAPK3。SlERF80與HSFA3(熱應激因子A3)相關,而SlERF9與熱應激因子共表達。由此可見,轉錄因子通過復雜的調控網絡提高對非生物、生物脅迫的抗性[123]。
番茄WRKY轉錄因子除了在病害方面具有調控作用外,在蟲害的調控響應中也有相關作用。如Bhattarai等報道,擬南芥轉錄因子AtWRKY72的2個番茄直系同源物SlWRKY72a、SlWRKY72b在由R基因Mi-1介導的抗性期間轉錄水平上調。在番茄中沉默這2個基因會導致Mi-1介導的抗性及對根結線蟲(root-knot nematodes,RKN)和馬鈴薯蚜蟲的基礎防御能力明顯降低,表明SlWRKY72a、SlWRKY72b在這些防御調控過程中具有重要作用[124]。Atamian等利用VIGS技術沉默SlWRKY70后,減弱了Mi-1介導的對馬鈴薯蚜蟲、根結線蟲RKN的抗性,表明SlWRKY70是Mi-1功能所必需的。此外,還發(fā)現SlWRKY70轉錄物可誘導響應蚜蟲侵染和RKN接種。Mi-1介導的對害蟲的識別調節(jié)了這種轉錄反應。如之前關于AtWRKY70的研究發(fā)現,SlWRKY70轉錄水平被SA上調并被MeJA抑制,表明WRKY70調控的某些方面在遠親真雙子葉植物中是保守的[125]。Chinnapandi等發(fā)現,根結線蟲能夠顯著誘導番茄SlWRKY45的表達,同時WRKY45受到特定植物激素的高度誘導,包括細胞分裂素、生長素和防御信號分子SA,而不是JA。進一步研究發(fā)現,SlWRKY45可能通過激素信號途徑調控根結線蟲在根組織中的發(fā)育過程[126]。Birhanu等發(fā)現,沉默番茄WRKY5會導致壞死病變、膜滲漏增加和細胞凋亡標記基因的表達量增加,從而推測WRKY5可能是細胞死亡的負調控因子[64]。
目前,番茄WRKY轉錄因子家族在生物脅迫方面的研究主要集中在枯萎病、灰霉病、致病疫霉、卷葉病、早疫病和丁香假單胞菌等病害脅迫方面。此外,番茄植株在其生長發(fā)育過程中還受到晚疫病病原、黃萎病病原、綿疫病病原、細菌性潰瘍病病原、猝倒病病原等生物病害的影響,有關番茄WRKY轉錄因子在生物脅迫方面的作用仍需要更系統、更深入研究。
2.4 番茄WRKY轉錄因子參與激素信號的轉導過程
植物激素在細胞分裂和伸長、組織器官分化、開花和結果、成熟和衰老、休眠和萌發(fā)及離體組織培養(yǎng)等方面調節(jié)植物的生長發(fā)育和分化。因此,植物激素對植物的生長發(fā)育具有重要的調控作用。WRKY轉錄因子可以通過調控與脫落酸(abscisic acid,ABA)、JA、SA、乙烯(ethylene,ET)等植物激素的合成來調控植物的生長發(fā)育或抗逆性[127-131]。有研究發(fā)現,番茄B. cinerea及JA能夠誘導LeWRKY1的表達,而SA對該基因沒有明顯的誘導作用,從而推測番茄LeWRKY1可能是通過JA依賴而SA非依賴的信號途徑參與番茄對番茄B. cinerea防御反應的應答,且LeWRKY1的表達不依賴生物體內JA的從頭合成[95,99,132-133]。Atamian等通過研究發(fā)現,番茄SlWRKY70是Mi-1介導的抗蚜蟲、根結線蟲所必需的,SlWRKY70轉錄水平被SA上調并被MeJA抑制,表明SlWRKY70可能通過激素信號途徑來調控番茄對Mi-1介導的抗性[125]。Mandal等通過研究發(fā)現,SA處理增加了SlWRKY16SlTRN1(對細胞擴張、靜脈形成很重要的基因)的轉錄水平。進一步研究得出,SA通路的激活會誘導SlWRKY16的表達,進而調節(jié)SlTRN1基因的轉錄,從而調控番茄植株對番茄卷葉病(tomato leaf curl disease)的抗性[112]。Lindo等通過試驗,從番茄中鑒定到1個WRKY40轉錄因子,且該轉錄因子在存在麥角甾醇、角鯊烯的情況下負調控SA相關基因并正調控ET、JA相關基因,從而參與調控植物的生長和防衛(wèi)過程[134]。周濤等通過研究表明番茄SlWRKY6轉錄因子可能通過參與ABA途徑來響應非生物脅迫[135]。Singh等從番茄中鑒定到1個主要在根中表達的基因SlWRKY23,通過研究發(fā)現,當用ET、細胞分裂素BAP和SA處理后,番茄WRKY轉錄因子SlWRKY23的轉錄水平上調,而用生長素(indoleacetic acid,IAA)處理后則抑制了其轉錄水平。轉基因擬南芥中SlWRKY23的表達影響了植株對ET、JA和IAA的敏感性,轉基因植株表現出對ET、JA和IAA介導的主根生長抑制的敏感性。這種超敏與介導對這些激素響應的ERF1、ARF5的高度表達相關。有研究結果表明,SlWRKY23可能通過調控與激素響應相關的基因來調控植物生長[35]。Shu等報道,SlWRKY46可能通過抑制抗氧化劑、抗病酶的活性,調節(jié)SA、JA信號通路及調節(jié)ROS穩(wěn)態(tài),在B. cinerea感染中發(fā)揮負調控作用[101]。Zhao等報道,番茄WRKY32能夠與YELLOW FRUITED-TOMATO 1 (YFT1)啟動子調控區(qū)域中的W-box、W-box-like基序結合并誘導其表達,而YFT1已證實是ET信號轉導途徑中的重要組成部分。進一步利用RNAi技術沉默WRKY32后,番茄果實中的ET信號傳導減弱,從而導致ET釋放受到抑制,染色質發(fā)育延遲,類胡蘿卜素積累減少,果實表型呈黃色。有研究發(fā)現,番茄WRKY32轉錄因子是通過調控ET信號轉導的核心成分YFT1來影響番茄果實顏色的[136]。Wang等通過研究發(fā)現,番茄SlWRKY37在葉片衰老中具有重要的作用,并通過降低對外部衰老信號(如JA和dark)的敏感性來延緩葉片變黃[137]。Rosado等報道,番茄在避陰響應(shade-avoidance response,SAR)過程中,遮陰誘導的WRKY26/45/75基因和ET重組基因在根中的表達會限制其生長發(fā)育[13]。
以上研究結果表明,番茄WRKY家族基因對激素的響應過程都是通過一系列信號傳導途徑及非常復雜的調控網絡來加以實現的,因此在后續(xù)研究中還有待深入探究其各個信號通路之間的機制及相關的生理代謝調控過程,從而為后期更好地研究番茄WRKY基因功能提供有效的信息資源。
3 展望
植物特異性的WRKY轉錄因子家族成員已在數十種植物中被發(fā)現,對其結構、表達特性和生物學功能的研究也越來越多。經過十幾年時間,番茄中WRKY轉錄因子家族的研究也取得了一定進展。部分基因的生物學功能得到鑒定,一些基因的分子機制也得到解析,這些研究結果能夠為后續(xù)研究提供一定的基礎。但是,番茄大部分WRKY基因的功能還有待研究,且基因的調控也不僅是單一的途徑,而是復雜的動態(tài)網絡,因此對番茄WRKY家族功能的解析仍然是具有挑戰(zhàn)的重大任務。隨著分子生物技術的發(fā)展,使基因工程技術能夠對關鍵WRKY轉錄因子進行調控和轉化,并可用于植物關鍵性狀的改良。因此,不斷挖掘和鑒定番茄中的WRKY轉錄因子,對番茄品種分子育種和改良的進展具有重要意義。
參考文獻:
[1]王榮青,楊悅儉,周國治,等. 番茄抗青枯病篩選方法及其在抗青枯病育種中的應用[J]. 浙江農業(yè)學報,2007,19(2):89-92.
[2]孫 妍,陳思宇,肖 健,等. 不同果實形狀番茄品種莖部內生細菌群落結構及代謝功能特征[J]. 西南農業(yè)學報,2021,34(12):2586-2595.
[3]Chitwood-Brown J,Vallad G E,Lee T G,et al. Breeding for resistance to Fusarium wilt of tomato:a review[J]. Genes,2021,12(11):1673.
[4]Olaniyi J O,Akanbi W B,Adejumo T,et al. Growth,fruit yield and nutritional quality of tomato varieties[J]. African Journal of Food Science,2010,4(6):398-402.
[5]Bhowmik D,Kumar K P S,Paswan S,et al. Tomato-a natural medicine and its health benefits[J]. Journal of Pharmacognosy and Phytochemistry,2012,1(1):33-43.
[6]Sujeet K,Ramanjini G P H,Banashree S,et al. Screening of tomato genotypes against bacterial wilt (Ralstonia solanacearum) and validation of resistance linked DNA markers[J]. Australasian Plant Pathology,2018,47:365-374.
[7]Golldack D,Lüking I,Yang O. Plant tolerance to drought and salinity:stress regulating transcription factors and their functional significance in the cellular transcriptional network[J]. Plant Cell Reports,2011,30(8):1383-1391.
[8]劉子剛,田佩耕,王 寧,等. 馬鈴薯StWRKY轉錄因子的克隆和生物信息學分析[J]. 西南農業(yè)學報,2022,35(2):432-437.
[9]Chen Y,Zhang H,Zhang M,et al. Salicylic acid-responsive factor TcWRKY33 positively regulates taxol biosynthesis in Taxus chinensis in direct and indirect ways[J]. Frontiers in Plant Science,2021,12:697476.
[10]Kang G J,Yan D,Chen X L,et al. HbWRKY82,a novel IIc WRKY transcription factor from Hevea brasiliensis associated with abiotic stress tolerance and leaf senescence in Arabidopsis[J]. Physiologia Plantarum,2021,171(1):151-160.
[11]Feng X,Abubakar A S,Yu C,et al. Analysis of WRKY resistance gene family in Boehmeria nivea (L.) Gaudich:crosstalk mechanisms of secondary cell wall thickening and cadmium stress[J]. Frontiers in Plant Science,2022,13:812988.
[12]Sun S S,Ren Y X,Wang D X,et al. A group I WRKY transcription factor regulates mulberry mosaic dwarf-associated virus-triggered cell death in Nicotiana benthamiana[J]. Molecular Plant Pathology,2022,23(2):237-253.
[13]Rosado D,Ackermann A,Spassibojko O,et al. WRKY transcription factors and ethylene signaling modify root growth during the shade-avoidance response[J]. Plant Physiology,2022,188(2):1294-1311.
[14]Ishiguro S,Nakamura K. Characterization of a cDNA encoding a novel DNA-binding protein,SPF1,that recognizes SP8 sequences in the 5′ upstream regions of genes coding for sporamin and pamylase from sweet potato[J]. Molecular and General Genetics,1994,244(6):563-571.
[15]Bencke-Malato M,Cabreira C,Wiebke-Strohm B,et al. Genome-wide annotation of the soybean WRKY family and functional characterization of genes involved in response to Phakopsora pachyrhizi infection[J]. BMC Plant Biology,2014,14(1):236.
[16]Ning P,Liu C C,Kang J Q,et al. Genome-wide analysis of WRKY transcription factors in wheat (Triticum aestivum L.) and differential expression under water deficit condition[J]. Peer J,2017,5:e3232.
[17]Zhang T,Tan D F,Zhang L,et al. Phylogenetic analysis and drought-responsive expression profiles of the WRKY transcription factor family in maize[J]. Agri Gene,2017,3:99-108.
[18]Ramamoorthy R,Jiang S Y,Kumar N,et al. A comprehensive transcriptional profiling of the WRKY gene family in rice under various abiotic and phytohormone treatments[J]. Plant and Cell Physiology,2008,49(6):865-879.
[19]Zhang C,Wang D D,Yang C H,et al. Genome-wide identification of the potato WRKY transcription factor family[J]. PLoS One,2017,12(7):1-20.
[20]Dong J X,Chen C H,Chen Z X. Expression profiles of the Arabidopsis WRKY gene superfamily during plant defense response[J]. Plant Molecular Biology,2003,51(1):21-37.
[21]Ling J,Jiang W J,Zhang Y,et al. Genome-wide analysis of WRKY gene family in Cucumis sativus[J]. BMC Genomics,2011,12:471.
[22]Yang B,Jiang Y Q,Rahman M H,et al. Identification and expression analysis of WRKY transcription factor genes in canola (Brassica napus L.) in response to fungal pathogens and hormone treatments[J]. BMC Plant Biology,2009,9(1):68.
[23]Huang S X,Gao Y F,Liu J K,et al. Genome-wide analysis of WRKY transcription factors in Solanum lycopersicum[J]. Molecular Genetics and Genomics,2012,287(6):495-513.
[24]張 紅,姜景彬,許向陽,等. 番茄WRKY基因家族的生物信息學分析[J]. 分子植物育種,2016,14(8):1965-1976.
[25]Eulgem T,Rushton P J,Robatzek S,et al. The WRKY superfamily of plant transcription factors[J]. Trends in Plant Science,2000,5(5):199-206.
[26]Rushton P J,Somssich I E,Ringler P,et al. WRKY transcription factors[J]. Trends in Plant Science,2010,15(5):247-258.
[27]Wu K L,Guo Z J,Wang H H,et al. The WRKY family of transcription factors in rice and Arabidopsis and their origins[J]. DNA Research,2005,12(1):9-26.
[28]Zhang Y J,Wang L J. The WRKY transcription factor superfamily:its origin in eukaryotes and expansion in plants[J]. BMC Evolutionary Biology,2005,5:1-13.
[29]Yang L,Zhao X,Yang F,et al. PtrWRKY19,a novel WRKY transcription factor,contributes to the regulation of pith secondary wall formation in Populus trichocarpa[J]. Scientific Reports,2016,6:18643.
[30]Wang Y,Li Y,He S P,et al. A cotton (Gossypium hirsutum) WRKY transcription factor (GhWRKY22) participates in regulating anther/pollen development[J]. Plant Physiology Biochemistry,2019,141:231-239.
[31]Zhou T T,Yang X M,Wang G B,et al. Molecular cloning and expression analysis of a WRKY transcription factor gene,GbWRKY20,from Ginkgo biloba[J]. Plant Signaling & Behavior,2021,16(10):1930442.
[32]Zhang Y,Yang X Q,Nvsvrot T,et al. The transcription factor WRKY75 regulates the development of adventitious roots,lateral buds and callus by modulating hydrogen peroxide content in poplar[J]. Journal of Experimental Botany,2022,73(5):1483-1498.
[33]Spyropoulou E A,Haring M A,Schuurink R C. RNA sequencing on Solanum lycopersicum trichomes identifies transcription factors that activate terpene synthase promoters[J]. BMC Genomics,2014,15(1):402.
[34]Li R,Shi C L,Wang X,et al. Inflorescence abscission protein SlIDL6 promotes low light intensity-induced tomato flower abscission[J]. Plant Physiology,2021,186(2):1288-1301.
[35]Singh D,Debnath P,Roohi,et al. Expression of the tomato WRKY gene,SlWRKY23,alters root sensitivity to ethylene,auxin and JA and affects aerial architecture in transgenic Arabidopsis[J]. Physiology and Molecular Biology of Plants,2020,26(6):1187-1199.
[36]Gu L J,Dou L L,Guo Y N,et al. The WRKY transcription factor GhWRKY27 coordinates the senescence regulatory pathway in upland cotton (Gossypium hirsutum L.)[J]. BMC Plant Biology,2019,19(1):116.
[37]Doll J,Muth M,Riester L,et al. Arabidopsis thaliana WRKY25 transcription factor mediates oxidative stress tolerance and regulates senescence in a redox-dependent manner[J]. Frontiers in Plant Science,2020,10:1734.
[38]Li L,Li K,Ali A,et al. AtWAKL10,a cell wall associated receptor-like kinase,negatively regulates leaf senescence in Arabidopsis thaliana[J]. International Journal of Molecular Sciences,2021,22(9):4885.
[39]Cao Z Y,Wu P Y,Gao H M,et al. Transcriptome-wide characterization of the WRKY family genes in Lonicera macranthoides and the role of LmWRKY16 in plant senescence[J]. Genes Genomics,2022,44(2):219-235.
[40]王 璐. 番茄果實后熟與葉片衰老相關的S1WRKY轉錄因子功能分析[D]. 廣州:華南農業(yè)大學,2016:31-46.
[41]Wang Z R,Gao M,Li Y F,et al. SlWRKY37 positively regulates jasmonic acid-and dark-induced leaf senescence in tomato[J]. Journal of Experimental Botany,2022,73(18):6207-6225.
[42]Cheng Y,Ahammed G J,Yu J H,et al. Corrigendum:Putative WRKYs associated with regulation of fruit ripening revealed by detailed expression analysis of the WRKY gene family in pepper[J]. Scientific Reports,2017,7:43498.
[43]Gan Z Y,Yuan X,Shan N,et al. AcWRKY40 mediates ethylene biosynthesis during postharvest ripening in kiwifruit[J]. Plant Science,2021,309:110948.
[44]Zhang W W,Zhao S Q,Gu S,et al. FvWRKY48 binds to the pectate lyase FvPLA promoter to control fruit softening in Fragaria vesca[J]. Plant Physiology,2022,189(2):1037-1049.
[45]賈 寧. 番茄后熟相關WRKY基因的表達調控[D]. 廣州:華南農業(yè)大學,2018:31-54.
[46]Liu X X,Huang Y M,Qiu Z K,et al. Comparative transcriptome analysis of differentially expressed genes between the fruit peel and flesh of the purple tomato cultivar ‘Indigo Rose[J]. Plant Signaling Behavior,2020,15(6):1752534.
[47]Yuan Y,Ren S R,Liu X F,et al. SlWRKY35 positively regulates carotenoid biosynthesis by activating the MEP pathway in tomato fruit[J]. New Phytologist,2022,234(1):164-178.
[48]Arhondakis S,Bita C E,Perrakis A,et al. In silico transcriptional regulatory networks involved in tomato fruit ripening[J]. Frontiers in Plant Science,2016,7:1234.
[49]Wang L,Zhang X L,Wang L,et al. Regulation of ethylene-responsive SlWRKYs involved in color change during tomato fruit ripening[J]. Scientific Reports,2017,7(1):16674.
[50]Shi W Y,Du Y T,Ma J,et al. The WRKY transcription factor GmWRKY12 confers drought and salt tolerance in soybean[J]. International Journal of Molecular Sciences,2018,19(12):4087.
[51]Dabi M,Agarwal P,Agarwal P K. Functional validation of JcWRKY2,a group Ⅲ transcription factor toward mitigating salinity Stress in transgenic tobacco[J]. DNA and Cell Biology,2019,38(11):1278-1291.
[52]Wang M Q,Huang Q X,Lin P,et al. The overexpression of a transcription factor gene VbWRKY32 enhances the cold tolerance in Verbena bonariensis[J]. Frontiers in Plant Science,2020,10:1746.
[53]Gulzar F,Fu J Y,Zhu C Y,et al. Maize WRKY transcription factor ZmWRKY79 positively regulates drought tolerance through elevating ABA biosynthesis[J]. International Journal of Molecular Sciences,2021,22(18):10080.
[54]Niu Y T,Li X T,Xu C,et al. Analysis of drought and salt-alkali tolerance in tobacco by overexpressing WRKY39 gene from Populus trichocarpa[J]. Plant Signaling Behavior,2021,16(7):1918885.
[55]Fei J,Wang Y S,Cheng H,et al. The Kandelia obovata transcription factor KoWRKY40 enhances cold tolerance in transgenic Arabidopsis[J]. BMC Plant Biology,2022,22(1):274.
[56]Yu S J,Lan X,Zhou J C,et al. Dioscorea composita WRKY3 positively regulates salt-stress tolerance in transgenic Arabidopsis thaliana[J]. Journal of Plant Physiology,2022,269:153592.
[57]劉 暢,牛向麗,劉繼愷,等. 番茄轉錄因子SlWRKY53的分離及生物學功能鑒定[J]. 四川大學學報(自然科學版),2013,50(6):1347-1354.
[58]孫曉春,高永峰,李會容,等. 番茄SlWRKY23基因的克隆及其抗病性和耐鹽性分析[J]. 中國農業(yè)科技導報,2014,16(5):39-46.
[59]張 凝,高永峰,孫曉春,等. 番茄SlWRKY1轉錄因子在植物生物和非生物脅迫中的調控[J]. 四川大學學報(自然科學版),2015,52(2):435-440.
[60]Kissoudis C. Genetics and regulation of combined abiotic and biotic stress tolerance in tomato[D]. Wageningen:Wageningen University,2016:32-54.
[61]Hichri I,Muhovski Y,iková E,et al. The Solanum lycopersicum WRKY3 transcription factor SlWRKY3 is involved in salt stress tolerance in tomato[J]. Frontiers in Plant Science,2017,8:1343.
[62]樊 蕾,高志英. 番茄SlWRKY44基因的克隆及表達[J]. 北方園藝,2018(22):6-10.
[63]Albaladejo I,Egea I,Morales B,et al. Identification of key genes involved in the phenotypic alterations of res (restored cell structure by salinity) tomato mutant and its recovery induced by salt stress through transcriptomic analysis[J]. BMC Plant Biology,2018,18(1):213.
[64]Birhanu M W,Kissoudis C,van der Linden C G,et al. WRKY gene silencing enhances tolerance to salt stress in transgenic tomato[J]. Journal of Biology,Agriculture and Healthcare,2020,10(17):14-25.
[65]Karkute S G,Easwaran M,Gujjar R S,et al. Protein modeling and molecular dynamics simulation of SlWRKY4 protein cloned from drought tolerant tomato (Solanum habrochaites) line EC520061[J]. Journal of Molecular Modeling,2015,21(10):255.
[66]Ahammed G J,Li X,Yang Y,et al. Tomato WRKY81 acts as a negative regulator for drought tolerance by modulating guard cell H2O2-mediated stomatal closure[J]. Environmental and Experimental Botany,2019,171:103960.
[67]Ahammed G J,Li X,Mao Q,et al. The SlWRKY81 transcription factor inhibits stomatal closure by attenuating nitric oxide accumulation in the guard cells of tomato under drought[J]. Physiologia Plantarum,2021,172(2):885-895.
[68]Zhou J,Wang J,Yu J Q,et al. Role and regulation of autophagy in heat stress responses of tomato plants[J]. Frontiers in Plant Science,2014,5:174.
[69]Chen L,Yang Y,Liu C,et al. Characterization of WRKY transcription factors in Solanum lycopersicum reveals collinearity and their expression patterns under cold treatment[J]. Biochemical and Biophysical Research Communications,2015,464(3):962-968.
[70]Zhou J,Wang J,Zheng Z Y,et al. Characterization of the promoter and extended C-terminal domain of Arabidopsis WRKY33 and functional analysis of tomato WRKY33 homologues in plant stress responses[J]. Journal of Experimental Botany,2015,66(15):4567-4583.
[71]王夢琪. 番茄乙烯響應因子ERF15在低溫抗性中的作用[D]. 杭州:浙江大學,2016:15-45.
[72]王藝璇,孟慶偉,馬娜娜. 番茄低溫響應WRKY轉錄因子的鑒定和分析[J]. 植物生理學報,2021,57(6):1349-1362.
[73]周靖翔. 低溫脅迫下番茄果實的冷應激反應及抗冷相關因子的篩選與分析[D]. 淄博:山東理工大學,2021:23-54.
[74]Guo M Y,Yang F J,Liu C X,et al. A single-nucleotide polymorphism in WRKY33 promoter is associated with the cold sensitivity in cultivated tomato[J]. New Phytologist,2022,236(3):989-1005.
[75]Ye J,Wang X,Hu T X,et al. An InDel in the promoter of Al-ACTIVATED MALATE TRANSPORTER9 selected during tomato domestication determines fruit malate contents and aluminum tolerance[J]. The Plant Cell,2017,29(9):2249-2268.
[76]Wang Z R,Liu L,Su H,et al. Jasmonate and aluminum crosstalk in tomato:identification and expression analysis of WRKYs and ALMTs during JA/Al-regulated root growth[J]. Plant Physiology Biochemistry,2020,154:409-418.
[77]王 茹,陳 超,于麗杰,等. 番茄SlWRKY6基因克隆及其在重金屬脅迫下的表達分析[J]. 華北農學報,2021,36(1):54-62.
[78]金 慧,欒雨時. 番茄WRKY基因的克隆與分析[J]. 西北農業(yè)學報,2011,20(4):96-101.
[79]Li J B,Luan Y S,Jin H. The tomato SlWRKY gene plays an important role in the regulation of defense responses in tobacco[J]. Biochemical and Biophysical Research Communications,2012,427(3):671-676.
[80]Li J B,Luan Y S,Liu Z. Overexpression of SpWRKY1 promotes resistance to Phytophthora nicotianae and tolerance to salt and drought stress in transgenic tobacco[J]. Physiology Plantarum,2015,155(3):248-266.
[81]Li J B,Luan Y S,Liu Z. SpWRKY1 mediates resistance to Phytophthora infestans and tolerance to salt and drought stress by modulating reactive oxygen species homeostasis and expression of defense-related genes in tomato[J]. Plant Cell,Tissue and Organ Culture,2015,123(1):67-81.
[82]魏娟娟,楊 偉,潘 宇,等. 番茄WRKY41基因的克隆、表達分析與轉基因植株的獲得[J]. 西南大學學報(自然科學版),2017,39(1):46-54.
[83]Jafarov H R,Gasimov K G. Expression pattern of SlWRKY33 and SlERF5 in tomato plants under elevated salt concentration and water deficit[J]. Factors of Experimental Evolution of Organisms,2017,20:266-270.
[84]陳青奇,張 紅,姜景彬,等. 番茄部分WRKY基因非生物脅迫表達和SlWRKY50基因沉默分析[J]. 東北農業(yè)大學學報,2018,49(7):8-18.
[85]Ashrafi-Dehkordi E,Alemzadeh A,Tanaka N,et al. Meta-analysis of transcriptomic responses to biotic and abiotic stress in tomato[J]. PeerJ,2018,6:e4631.
[86]周 濤,王 娟,王露露,等. 番茄轉錄因子基因SlWRKY16的克隆及原核表達分析[J]. 園藝學報,2020,47(7):1312-1322.
[87]Gao Y F,Liu J K,Yang F M,et al. The WRKY transcription factor WRKY8 promotes resistance to pathogen infection and mediates drought and salt stress tolerance in Solanum lycopersicum[J]. Physiology Plantarum,2020,168(1):98-117.
[88]Liu Q,Li X,Yan S J,et al. OsWRKY67 positively regulates blast and bacteria blight resistance by direct activation of PR genes in rice[J]. BMC Plant Biology,2018,18(1):257.
[89]Cui X X,Yan Q,Gan S P,et al. GmWRKY40,a member of the WRKY transcription factor genes identified from Glycine max L.,enhanced the resistance to Phytophthora sojae[J]. BMC Plant Biology,2019,19(1):598.
[90]Wang X,Li J J,Guo J,et al. The WRKY transcription factor PlWRKY65 enhances the resistance of Paeonia lactiflora (herbaceous peony) to Alternaria tenuissima[J]. Horticulture Research,2020,7:57.
[91]Chen T T,Li Y P,Xie L H,et al. AaWRKY17,a positive regulator of artemisinin biosynthesis,is involved in resistance to Pseudomonas syringae in Artemisia annua[J]. Horticulture Research,2021,8(1):217.
[92]Yang S,Zhang Y W,Cai W W,et al. CaWRKY28 Cys249 is required for interaction with CaWRKY40 in the regulation of pepper immunity to Ralstonia solanacearum[J]. Molecular Plant-Microbe Interactions,2021,34(7):733-745.
[93]Wang Z,Deng J,Liang T T,et al. Lilium regale Wilson WRKY3 modulates an antimicrobial peptide gene,LrDef1,during response to Fusarium oxysporum[J]. BMC Plant Biology,2022,22(1):257.
[94]Xu X H,Wang H,Liu J Q,et al. OsWRKY62 and OsWRKY76 interact with importin α1s for negative regulation of defensive responses in rice nucleus[J]. Rice,2022,15(1):12.
[95]王麗芳,于涌鯤,杜希華,等. 茉莉酸等3種因素刺激番茄LeWRKY1的表達特征分析[J]. 中國農學通報,2010,26(23):73-76.
[96]Molan Y Y,El-Komy M H. Expression of Sl-WRKY1 transcription factor during B. cinerea tomato interaction in resistant and susceptible cultivars[J]. International Journal of Plant Breeding Genetics,2010,4(1):1-12.
[97]孫清鵬,李 娜,于涌鯤,等. LeWRKY2基因的克隆及功能分析[J]. 中國農業(yè)科學,2012,45(7):1257-1264.
[98]Liu B,Hong Y B,Zhang Y F,et al. Tomato WRKY transcriptional factor SlDRW1 is required for disease resistance against Botrytis cinerea and tolerance to oxidative stress[J]. Plant Science,2014,227(5):145-156.
[99]Lu M,Wang L F,Du X H,et al. Molecular cloning and expression analysis of jasmonic acid dependent but salicylic acid independent LeWRKY1[J]. Genetics and Molecular Research,2015,14(4):15390-15398.
[100]蔡 俊. SlWRKY3通過TPK1b負調控番茄對灰霉病的抗性[D]. 武漢:華中農業(yè)大學,2020:25-33.
[101]Shu P,Zhang S J,Li Y J,et al. Over-expression of SlWRKY46 in tomato plants increases susceptibility to Botrytis cinerea by modulating ROS homeostasis and SA and JA signaling pathways[J]. Plant Physiology and Biochemistry,2021,166:1-9.
[102]Huang H,Zhao W C,Li C H,et al. SlVQ15 interacts with jasmonate-ZIM domain proteins and SlWRKY31 to regulate defense response in tomato[J]. Plant Physiology,2022,190(1):828-842.
[103]曾 輝,高永峰,劉繼愷,等. 番茄SlWRKY80基因共抑制表達影響轉基因植株抗逆性的研究[J]. 四川大學學報(自然科學版),2014,51(5):1035-1042.
[104]Sun X C,Gao Y F,Li H R,et al. Over-expression of SlWRKY39 leads to enhanced resistance to multiple stress factors in tomato[J]. Journal of Plant Biology,2015,58(1):52-60.
[105]Ramos R N,Martin G B,Pombo M A,et al. WRKY22 and WRKY25 transcription factors are positive regulators of defense responses in Nicotiana benthamiana[J]. Plant Molecular Biology,2021,105(1/2):65-82.
[106]Li J B,Luan Y S. Molecular cloning and characterization of a pathogen-induced WRKY transcription factor gene from late blight resistant tomato varieties Solanum pimpinellifolium L3708[J]. Physiological and Molecular Plant Pathology,2014,87:25-31.
[107]劉 震. 番茄SpWRKY6轉錄因子的抗病功能研究[D]. 大連:大連理工大學,2016:19-52.
[108]Cui J,Xu P S,Meng J,et al. Transcriptome signatures of tomato leaf induced by Phytophthora infestans and functional identification of transcription factor SpWRKY3[J]. Theoretical and Applied Genetics,2018,131(4):787-800.
[109]Hong Y H,Cui J,Liu Z,et al. SpWRKY6 acts as a positive regulator during tomato resistance to Phytophthora infestans infection[J]. Biochemical and Biophysical Research Communications,2018,506(4):787-792.
[110]Cui J,Jiang N,Meng J,et al. LncRNA33732-respiratory burst oxidase module associated with WRKY1 in tomato-Phytophthora infestans interactions[J]. The Plant Journal,2019,97(5):933-946.
[111]Hofmann M G,Sinha A K,Proels R K,et al. Cloning and characterization of a novel LpWRKY1 transcription factor in tomato[J]. Plant Physiology and Biochemistry,2008,46(5/6):533-540.
[112]Mandal A,Sarkar D,Kundu S,et al. Mechanism of regulation of tomato TRN1 gene expression in late infection with tomato leaf curl New Delhi virus (ToLCNDV)[J]. Plant Science,2015,241:221-237.
[113]Roylawar P,Panda S,Kamble A. Comparative analysis of BABA and Piriformospora indica mediated priming of defence-related genes in tomato against early blight[J]. Physiological and Molecular Plant Pathology,2015,91:88-95.
[114]Shinde B A,Dholakia B B,Hussain K,et al. Dynamic metabolic reprogramming of steroidal glycol-alkaloid and phenylpropanoid biosynthesis may impart early blight resistance in wild tomato (Solanum arcanum Peralta)[J]. Plant Molecular Biology,2017,95(4/5):411-423.
[115]Shinde B A,Dholakia B B,Hussain K,et al. WRKY1 acts as a key component improving resistance against Alternaria solani in wild tomato,Solanum arcanum Peralta[J]. Plant Biotechnology Journal,2018,16(8):1502-1513.
[116]崔丹丹. 番茄青枯病發(fā)病過程中ARFs和WRKYs的表達分析[D]. 廣州:華南農業(yè)大學,2018:29-35.
[117]Naveed Z A,Ali G S. Comparative transcriptome analysis between a resistant and a susceptible wild tomato accession in response to Phytophthora parasitica[J]. International Journal of Molecular Sciences,2018,19(12):3735.
[118]Pentimone I,Colagiero M,Ferrara M,et al. Time-dependent effects of Pochonia chlamydosporia endophytism on gene expression profiles of colonized tomato roots[J]. Applied Microbiology and Biotechnology,2019,103(20):8511-8527.
[119]Du H S,Wang Y Q,Yang J J,et al. Comparative transcriptome analysis of resistant and susceptible tomato lines in response to infection by Xanthomonas perforans Race T3[J]. Frontiers in Plant Science,2015,6(428):161-171.
[120]Huang Y,Li M Y,Wu P,et al. Members of WRKY Group Ⅲ transcription factors are important in TYLCV defense signaling pathway in tomato (Solanum lycopersicum)[J]. BMC Genomics,2016,17(1):788.
[121]Aamir M,Singh V K,Dubey M K,et al. Structural and functional dissection of differentially expressed tomato WRKY transcripts in host defense response against the vascular wilt pathogen (Fusarium oxysporum f. sp. lycopersici)[J]. PLoS One,2018,13(4):1-43.
[122]Aamir M,Kashyap S P,Zehra A,et al. Trichoderma erinaceum bio-priming modulates the WRKYs defense programming in tomato against the Fusarium oxysporum f. sp. lycopersici (Fol) challenged condition[J]. Frontiers in Plant Science,2019,10:911.
[123]Gharsallah C,Gharsallah Chouchane S,Werghi S,et al. Tomato contrasting genotypes responses under combined salinity and viral stresses[J]. Physiology and Molecular Biology of Plants,2020,26(7):1411-1424.
[124]Bhattarai K K,Atamian H S,Kaloshian I,et al. WRKY72-type transcription factors contribute to basal immunity in tomato and Arabidopsis as well as gene-for-gene resistance mediated by the tomato R gene Mi-1[J]. Plant Journal,2010,63(2):229-240.
[125]Atamian H S,Eulgem T,Kaloshian I. SlWRKY70 is required for Mi-1-mediated resistance to aphids and nematodes in tomato[J]. Planta,2012,235(2):299-309.
[126]Chinnapandi B,Bucki P,Braun Miyara S. SlWRKY45,nematode-responsive tomato WRKY gene,enhances susceptibility to the root knot nematode;M. javanica infection[J]. Plant Signaling Behavior,2017,12(12):e1356530.
[127]Hu Z R,Wang R,Zheng M,et al. TaWRKY51 promotes lateral root formation through negative regulation of ethylene biosynthesis in wheat (Triticum aestivum L.)[J]. The Plant Journal,2018,96(2):372-388.
[128]Ma Q B,Xia Z L,Cai Z D,et al. GmWRKY16 enhances drought and salt tolerance through an ABA-mediated pathway in Arabidopsis thaliana[J]. Frontiers in Plant Science,2019,9:1979.
[129]Zhao L,Zhang W J,Song Q H,et al. A WRKY transcription factor,TaWRKY40-D,promotes leaf senescence associated with jasmonic acid and abscisic acid pathways in wheat[J]. Plant Biology,2020,22(6):1072-1085.
[130]Bi M M,Li X Y,Yan X,et al. Chrysanthemum WRKY15-1 promotes resistance to Puccinia horiana Henn. via the salicylic acid signaling pathway[J]. Horticulture Research,2021,8(1):6.
[131]LimC,KangK,ShimY,etal.InactivatingtranscriptionfactorOsWRKY5 enhances drought tolerance through abscisic acid signaling pathways[J]. Plant Physiology,2022,188(4):1900-1916.
[132]于涌鯤,王麗芳,杜希華,等. LeWRKY1基因的克隆及分析[J]. 植物生理學報,2010,46(12):1225-1231.
[133]Wang L F,Yu Y K,Du X H,et al. Research on expression of LeWRKY1 in tomato induced by jasmonic acid and other two factors[J]. Agricultural Science & Technology,2011,12(8):1133-1135,1138.
[134]Lindo L,Cardoza R E,Lorenzana A,et al. Identification of plant genes putatively involved in the perception of fungal ergosterol-squalene[J]. Journal of Integrative Plant Biology,2020,62(7):927-947.
[135]周 濤,王 娟,胡佳蕙,等. 番茄轉錄因子基因SlWRKY6的克隆與原核表達分析[J]. 西北植物學報,2020,40(11):1824-1832.
[136]Zhao W H,Li Y H,Fan S Z,et al. The transcription factor WRKY32 affects tomato fruit colour by regulating YELLOW FRUITED-TOMATO 1,a core component of ethylene signal transduction[J]. Journal of Experimental Botany,2021,72(12):4269-4282.
[137]Wang Z R,Gao M,Li Y F,et al. SlWRKY37 positively regulates jasmonic acid-and dark-induced leaf senescence in tomato[J]. Journal of Experimental Botany,2022,73(18):6207-6225.