摘" " 要:【目的】探究DdSOC1基因調(diào)控德陽柿(Diospyros deyangensis)成花的分子機制?!痉椒ā客ㄟ^生物信息學、基因表達量分析、酵母雙雜篩庫和雙雜互作驗證等方法,解析DdSOC1基因在調(diào)控成花中的功能?!窘Y(jié)果】德陽柿DdSOC1序列和君遷子DlSOC1序列遺傳距離較近;在成花誘導過程中,DdSOC1在莖、葉、芽中隨開花進程出現(xiàn)差異表達;基于柿酵母文庫,篩選獲得7個DdSOC1的互作蛋白(MIOX、AGL14、JOINTLESS、GL2、NOVEIN、NBS、UBC7),酵母雙雜交和雙分子熒光互補試驗表明,DdSOC1和上述7個蛋白均互作;qRT-PCR結(jié)果顯示,一年生已開花的德陽柿SOC1、AGL14、JOINTLESS、NOVEIN、GL2、UBC7、NBS的表達量,幼葉高于成齡葉;二年生實生苗中,SOC1表達量差異不大,而AGL14、JOINTLESS、GL2、UBC7、MIOX表達量在開花實生苗中的表達量高于未開花實生苗。【結(jié)論】DdSOC1及其互作蛋白在德陽柿成花轉(zhuǎn)變中發(fā)揮著重要作用,為探究德陽柿短童期分子調(diào)控網(wǎng)絡提供了更多理論依據(jù)。
關鍵詞:德陽柿;DdSOC1;互作蛋白;酵母雙雜交;雙分子熒光互補;實時熒光定量分析
中圖分類號:S665.2 文獻標志碼:A 文章編號:1009-9980(2025)02-0276-12
Molecular mechanism of DdSOC1 gene regulating flower bud initiation in Diospyros deyangensis
WAN Jianqi1, DING Yu1, REN Han1, LI Wenxia1, YANG Yong1, HUANG Jinmeng2, GUAN Changfei1*
(1College of Horticulture, Northwest A amp; F University, Yangling 712100, Shaanxi, China; 2Guangxi Academy of Specialty Crops, Guilin 541004, Guangxi, China)
Abstract: 【Objective】 Seedlings of the new identified persimmon species Diospyros deyangensis have a short juvenile stage and can flower within one year after seed sowing. The function of the DdSOC1 gene in controlling flower bud initiation in D. deyangensis was investigated, along with its sequence characterization and expression pattern. 【Methods】 Plant materials were obtained from Nicotiana tabacum and 1- and 2-year-old persimmon (D. deyangensis) seedlings cultivated in the orchard at Northwest A amp; F University under natural conditions. Online analysis of the open reading frame of DdSOC1 was done using the ORF Finder. The physicochemical property of the encoded protein was predicted using Expasy ProtParam program. The MEGA7.0 software was used to create the phylogenetic tree. QRT-PCR was used to examine the expression features of DdSOC1. On the one-deficient and three-deficient plates, the self-toxicity and self-activation of DdSOC1 were explored. Verification of the screening library and yeast interaction was done on a four-lack plate. Confocal microscopy was used in the BiFC experiment. 【Results】 The findings demonstrated that D. deyangnsis SOC1 shared a close genetic distance with SOC1 from Diospyros lotus, Actinidia chinensis, Actinidia eriantha, Camellia sinensis and other species. Populus alba, Vitis vinifera, Malus domestica, Prunus persica, Mangifera indica and other species were distantly linked to D. deyangnsis SOC1 protein. Furthermore, D. deyangnsis SOC1 protein was the most distantly related to that of the herbaceous plants Triticum aestivum and Oryza sativa. Online analysis demonstrated that DdSOC1 protein encodes 126 amino acids. The molecular weight is 14.56 ku. Its isoelectric point is 5.62. SOC1 expression was the highest during flowering and lowest during the bud stage in annual flowering D. deyangnsis stems. As the flowering process progressed, SOC1 expression in the leaves rose. SOC1 expression in the buds peaked during the seedling stage and decreased during the flowering stage. For Y2H, the first deficient plate had plaques, whereas the third plate had none. It demonstrated that DdSOC1 did not have autotoxicity and autoactivation. Following that, DdSOC1 was employed as the bait protein to test the cDNA library of Fuping persimmon. Following colony PCR, the blue plaque on the four-deficient plate in the sieve library was forwarded for sequencing. By comparing the sequences obtained from the screening library with the NCBI BLAST and the genome annotation of D. deyangnsis, seven putative interacting proteins (MIOX, AGL14, JOINTLESS, GL2, NOVEIN, NBS and UBC7) were screened out. The AD vectors of JOINTLESS, NOVEIN, GL2 and other interacting proteins were introduced into BD-SOC1 yeast-competent cells to verify yeast two-hybrid interactions. PGBKT7-53 + pGADT7-T, pGBKT7-Lam + pGADT7-T, and BD-SOC1 + pGADT7 were used as positive, negative and blank control. The combined plasmid was effectively transferred into yeast strains. The findings demonstrated that nine sets of yeast combinations were able to establish white colonies on DDO plates. Plaque was absent from both negative and blank controls on QDO and QDO/X/A plates. On QDO/X/A plates, the positive control and seven yeast combinations (BD-SOC1+AD-NBS, BD-SOC1+AD-JOINTLESS, BD-SOC1+AD-UBC7, BD-SOC1+AD-MIOX, BD-SOC1+AD-GL2, BD-SOC1+AD-NOVEIN and BD-SOC1+AD-AGL14) could grow properly and turn blue. The SOC1 protein and interaction proteins MIOX, JOINTLESS, AGL14, NOVEIN, UBC7 and GL2 in D. deyangensis were evaluated based on the results of the yeast two-hybrid. The pSPYCE (CE) vector of putative interacting proteins and the pSPYNE (NE) vector of DdSOC1 were constructed. Following co-injection, YFP fluorescence signals were seen in tobacco cells. The findings demonstrated that JOINTLESS-cYFP + SOC1-nYFP produced the strongest yellow fluorescence in the tobacco cell membrane and nucleus out of the seven combinations. Other combinations (NOVEIN-cYFP + SOC1-nYFP, UBC7-cYFP + SOC1-nYFP, NBS-cYFP + SOC1-nYFP, GL2-cYFP + SOC1-nYFP and MIOX-cYFP + SOC1-nYFP) detected yellow fluorescence on the cell membrane, while the combination of AGL14-cYFP+SOC1-nYFP produced yellow fluorescence in the nucleus. According to the aforementioned findings, DdSOC1 interacted with seven potential plant interacting proteins. D. deyangensis seedlings with various characteristics (flowering and non-flowering) were examined for the expression of DdSOC1 and its interaction proteins in young leaves (leaves close to the apical bud) and mature leaves (adult leaves distant from the apical bud). According to the findings, juvenile leaves had higher expression levels of SOC1, AGL14, JOINTLESS, NOVEIN, GL2, UBC7 and NBS than mature leaves, but younger leaves had lower expression levels of MIOX. The expression levels of SOC1, NOVEIN and MIOX in young leaves were lower than those in mature leaves in the two-year-old D. deyangensis seedlings, whereas the other genes (GL2, UBC7, NBS, AGL14 and JOINTLESS) exhibited a contrast pattern. 【Conclusion】 This study isolated and cloned the DdSOC1 gene, which was relatively conserved in the evolution of woody plants; DdSOC1 integrated flowering signals from leaves to achieve the transition from vegetative growth to reproductive growth; the results from Y2H and BiFC confirmed that DdSOC1 interacted with interaction protein (MIOX, AGL14, JOINTLESS, GL2, NOVEIN, NBS and UBC7); MIOX may play a role in delaying flowering, while AGL14, JOINTLESS, GL2 and NBS may have a positive influence on the short-childhood of D. deyangensis.
Key words: Diospyros deyangensis; DdSOC1; Interaction protein; Y2H; BiFC; qPCR
德陽柿(Diospyros deyangensis)原產(chǎn)于四川省德陽市,是柿科(Ebenaceae)柿屬(Diospyros)多年生木本植物,屬于雌雄異株落葉果樹樹種,又稱紅花野毛柿。前人通過形態(tài)學觀察、分子標記、染色體倍性分析等手段發(fā)現(xiàn)德陽柿為四倍體,屬于柿屬植物新種[1-2]。木本果樹植物的生命周期分為童期、成年期和衰老期,其中,童期指從種子萌發(fā)至具備正常開花能力的時期。木本植物的童期普遍較長,一般為3~8 a(年)[3],云杉甚至需要20~25 a才能進入成年期[4]。然而,德陽柿作為栽培柿(Diospyros kaki)的近緣種,在播種數(shù)月后即可開花[5],是研究柿屬植物短童期花發(fā)育機制的優(yōu)良試材。研究短童期調(diào)控的分子機制對促進柿早花結(jié)實、提高育種效率具有重要的理論意義和實踐價值。
通過對模式植物擬南芥的研究,發(fā)現(xiàn)了調(diào)控植物開花的重要整合因子SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1)[6]。SOC1隸屬于MADS-box基因家族,它可以整合來自光周期、春化作用、自主途徑等多個開花調(diào)控途徑的信號,隨后將信號傳遞給下游的花分生組織基因進而促進植物成花轉(zhuǎn)化[6-7]。目前已從多種植物,如甜橙(Citrus sinensis)、銀白楊(Populus trichocarpa)、蘋果(Malus domestica)、歐洲葡萄(Vitis vinifera)中克隆出SOC1同源基因[8-11]。SOC1調(diào)控開花的機制也被廣泛研究[12]。前人研究發(fā)現(xiàn),B3結(jié)構(gòu)域轉(zhuǎn)錄因子REM16通過結(jié)合SOC1和FT(FLOWERING LOCUS T)的啟動子促進擬南芥開花[13];BjuWRKY71-1通過調(diào)節(jié)SOC1的表達促進芥菜開花[14];應激誘導型啟動子rd29A通過促進AtSOC1的過表達可以將干旱脅迫下菊花的開花時間提前[15]。以上研究表明SOC1作為轉(zhuǎn)錄因子受到其他蛋白或核酸的調(diào)控后調(diào)節(jié)植物的開花時間。此外,SOC1也可以與其他蛋白質(zhì)形成二聚體或高階復合物靶向調(diào)控開花基因進而影響植物開花節(jié)奏[16]。SOC1和AGL6亞家族同源物DAL1相互作用介導松樹營養(yǎng)生長到生殖生長的轉(zhuǎn)變[4];TaSOC1通過與MADS-box開花調(diào)節(jié)因子TaVRT2競爭結(jié)合TaVRN1,形成TaSOC1-TaVRN1模塊,整合光周期和春化信號,調(diào)控小麥開花[17];BrSOC1b通過與BrAGL9a、BrAGL9b、BrAGL2和BrAGL8蛋白相互作用,共同參與調(diào)節(jié)白菜的開花[18];擬南芥中SOC1與AGL16形成蛋白質(zhì)復合物,共同作用于開花靶標基因[19]。SOC1在調(diào)控植物開花時間的過程中起到關鍵的作用,然而至今還未有德陽柿SOC1基因相關的報道,SOC1基因在德陽柿短童期中的作用也尚不清楚。
筆者在本研究中基于前期獲得的德陽柿基因組數(shù)據(jù),分離DdSOC1基因并分析其序列特征,探究DdSOC1基因在不同組織器官中的表達模式;通過酵母雙雜交(Y2H)篩庫得到DdSOC1的互作蛋白并進行了Y2H、雙分子熒光互補(BiFC)的互作驗證;分析1年生、2年生德陽柿實生苗蕾期葉片中互作蛋白基因的表達量,以期探究DdSOC1基因在德陽柿短童期中的功能,為研究德陽柿短童期分子調(diào)控網(wǎng)絡提供理論依據(jù)。
1 材料和方法
1.1 試驗材料
植物材料為種植于陜西楊凌西北農(nóng)林科技大學國家柿種質(zhì)資源圃(34°17′42.80″ N,108°04′8.21″ E)的1年生、2年生德陽柿(D. deyangensis)實生苗;本氏煙(Nicotiana tabacum)。用于實時熒光定量的試驗材料取自1年生、2年生德陽柿蕾期實生苗葉片。
菌株:富平尖柿的酵母雙雜交文庫,Y2H Gold酵母菌株以及轉(zhuǎn)入pGBKT7空載、陽性對照(pGBKT7-53+pGADT7-T)、陰性對照(pGBKT7-Lam+pGADT7-T)的酵母菌株。
載體:Y2H載體pGBKT7(BD)、pGADT7(AD);BiFC載體pSPYNE(NE)、pSPYCE(CE)。
1.2 DdSOC1基因的克隆和序列分析
使用天根生化科技有限公司多糖多酚試劑盒(DP441)提取德陽柿葉片RNA,使用艾科瑞生物工程有限公司Evo M-MLV反轉(zhuǎn)錄試劑盒(AG11728)將所提RNA反轉(zhuǎn)錄合成模板cDNA。根據(jù)基因組數(shù)據(jù)查詢基因的序列,利用SnapGene Viewer 2.4.3軟件進行引物設計(表1)。采用艾科瑞高保真試劑盒(AG12202)擴增CDS序列。DNA片段連接到pMD19-T載體后轉(zhuǎn)化至大腸桿菌DH5α中,經(jīng)過菌落PCR和測序,最終得到陽性克隆。
使用ORF Finder(https://www.ncbi.nlm.nih.gov/orffinder/)在線分析開放閱讀框,使用Expasy中的ProtParam(https://www.expasy.org/)工具預測編碼蛋白的等電點和分子質(zhì)量,在NCBI上進行SOC1-like蛋白搜索,下載相似性較高的蛋白質(zhì)序列,利用MEGA 7.0軟件,選擇鄰接法將相關物種的SOC1序列構(gòu)建系統(tǒng)進化樹(bootstrap設為1000次)。
1.3 DdSOC1基因的表達特征
采用qRT-PCR分析DdSOC1基因的表達特征,引物見表1。將cDNA質(zhì)量濃度稀釋至200 ng·μL-1后作為模板,用SYBR Green Pro Taq HS預混型qPCR試劑盒(含Rox)(AG11718)進行定量實驗。
取一年生開花德陽柿實生苗莖、葉、芽三個部位,在苗期、蕾期以及花期測定DdSOC1表達水平。
1.4 DdSOC1自毒自激活驗證及互作蛋白篩選
1.4.1 DdSOC1自激活驗證 以DdSOC1的連T載體質(zhì)粒為模板,設計pGBKT7(簡稱BD)引物(表1)并擴增,用SmaⅠ和BamHⅠ對BD進行雙酶切,同源重組后,通過菌液PCR和測序比對獲得重組載體pGBKT7-DdSOC1(BD-SOC1)。依照酵母感受態(tài)制備及轉(zhuǎn)化試劑盒(PT1183,源葉生物),獲得BD-SOC1陽性酵母菌株。
在SD/-Trp培養(yǎng)基上分別點BD-SOC1和BD空載的酵母菌液,28 ℃倒置培養(yǎng)2~3 d后觀察酵母生長情況,若BD-SOC1在SD/-Trp平板上正常生長則表明其對酵母菌株無毒性。
在SD/-Trp/-Ade/-His+X-α-Gal(TDO/X)上分別點上陽性對照(pGBKT7-53+pGADT7-T)、陰性對照(pGBKT7-Lam+pGADT7-T)、pGBKT7空載(BD-empty)、BD-SOC1,觀察酵母的生長情況。若BD-SOC1的菌液在三缺板上不長斑則說明不存在自激活,可直接進行后續(xù)的篩庫試驗,若在三缺板上長斑并變藍,則需篩選合適的抑制劑濃度抑制其自激活。
1.4.2 DdSOC1酵母文庫篩選 將柿的核次級文庫質(zhì)粒轉(zhuǎn)入BD-SOC1的酵母感受態(tài)細胞中,經(jīng)過轉(zhuǎn)化后,將菌液涂布至SD/-Trp/-Leu/-Ade/-His(QDO)培養(yǎng)基上,觀察單菌落生長情況。挑取單菌落,稀釋后點至SD/-Trp/-Leu/-Ade/-His/X-α-Gal/AbA(QDO/X/A)上,觀察是否有變藍的菌落。
菌落PCR及測序:將藍色單菌落挑至離心管中加入20 μL裂解液(Lysis Buffer for Microorganism to Direct PCR,9164,寶日醫(yī)),熱變性后低速離心,取上清液作為模板進行菌落PCR。選擇電泳條帶大于500 bp且單一的菌落PCR產(chǎn)物送至上海生工生物工程有限公司測序(表2)。
1.4.3 互作蛋白克隆 將篩庫測序得到的序列在NCBI的BLAST數(shù)據(jù)庫中進行比對,根據(jù)功能注釋篩選互作蛋白,在德陽柿基因組中找出對應的CDS序列,并設計擴增引物(表3)。
1.5 酵母雙雜交(Y2H)
設計互作蛋白pGADT7(AD)的引物(表4)并擴增,用SmaⅠ和BamHⅠ對AD載體進行雙酶切,同源重組后,對菌落PCR、提質(zhì)粒及測序。
參照1.4.2方法,將空載(AD-empty)質(zhì)粒及互作蛋白的AD質(zhì)粒分別轉(zhuǎn)入BD-SOC1酵母感受態(tài)細胞,處理后的菌液涂布至DDO(SD/-Trp/-Leu)平板上。培養(yǎng)至長出單菌落后,挑取單菌落點至DDO、QDO/X/A板上,觀察酵母生長及變色情況。設置陽性和陰性對照。
1.6 雙分子熒光互補(BiFC)
設計DdSOC1的pSPYNE(NE)以及互作蛋白pSPYCE(CE)的引物(表1,表5)并擴增,同源重組后測序檢測,并提取重組質(zhì)粒備用。
參照農(nóng)桿菌感受態(tài)說明書將重組質(zhì)粒轉(zhuǎn)化至農(nóng)桿菌感受態(tài)GV3101中,利用菌落PCR鑒定陽性菌株,在雙抗LB液體培養(yǎng)基中培養(yǎng)。離心后棄上清液,用MES溶液重懸菌液,OD600值調(diào)整至0.8后加入乙酰丁香酮,室溫黑暗靜置。將CE和NE侵染液等比例混合,將農(nóng)桿菌侵染液注射進煙草葉背,暗培養(yǎng)48 h。使用激光共聚焦顯微鏡(TCS SP8 SR,Leica,德國)觀察YFP熒光。
1.7 互作基因表達分析
參照1.3的方法,設計互作蛋白的定量引物(表6),取蕾期1年生、2年生德陽柿(D. deyangensis)實生苗頂芽附近3~4枚葉(幼葉)及枝條基部的成年葉分析互作基因表達量。
1.8 數(shù)據(jù)統(tǒng)計和分析
所有處理均包括3次重復,數(shù)據(jù)均表示為平均值±標準誤差,統(tǒng)計分析和作圖使用GraphPad Prism 8軟件完成。
2 結(jié)果與分析
2.1 DdSOC1基因的克隆和序列分析
以德陽柿葉的cDNA為模板擴增得到DdSOC1基因,經(jīng)測序驗證擴增得到的序列與德陽柿基因組序列一致。該基因CDS全長381 bp,編碼126個氨基酸;蛋白質(zhì)的分子質(zhì)量為14.56 ku、等電點為5.62。
利用MEGA 7.0軟件對德陽柿及其他物種的SOC1序列進行系統(tǒng)發(fā)育樹分析,結(jié)果(圖1)顯示,DdSOC1和DlSOC1關系最近,形成一個小的分支,與中華獼猴桃、毛花獼猴桃、茶SOC1蛋白序列一致性較高;與銀白楊、歐洲葡萄、蘋果、桃、杧果等SOC1蛋白的親緣關系較遠;與水稻、小麥SOC1蛋白親緣關系最遠。
2.2 DdSOC1基因的表達特征
1年生開花德陽柿不同器官(莖、葉、芽)在不同時期SOC1的定量結(jié)果(圖2)顯示,莖中SOC1表達量在蕾期最低,而在花期達到最高;葉中SOC1表達量隨著開花進程逐漸升高;芽中SOC1的表達量在幼苗期最高,而在花期最低。
2.3 DdSOC1自毒自激活驗證及酵母文庫篩選
分別在SD/-Trp和SD/-Trp/Ade/His + X-α-gal培養(yǎng)基上對DdSOC1毒性及自激活進行檢測,結(jié)果如圖3所示,在SD/-Trp培養(yǎng)基上,BD-SOC1長出菌落,說明BD-SOC1對酵母菌生長無影響;在SD/-Trp/-Ade/-His + X-α-gal培養(yǎng)基上,只有陽性對照(Po)長出菌斑,陰性對照(Ne)、空白對照(BD-empty)、BD-SOC1均未長出菌斑,說明DdSOC1沒有自激活現(xiàn)象。
酵母篩庫結(jié)果顯示,BD-SOC1質(zhì)粒與酵母文庫質(zhì)粒共轉(zhuǎn)入的酵母菌在QDO板上長出白色單菌落,其在QDO/X/A板上均變藍。對QDO/X/A上變藍單菌落進行菌落PCR檢測,選擇大于500 bp的條帶測序;利用NCBI BLAST以及德陽柿基因組注釋對比后從中篩選出7條候選互作蛋白(AGL14、JOINTLESS、NOVEIN、GL2、UBC7、NBS、MIOX)。
2.4 酵母雙雜交(Y2H)
酵母試驗結(jié)果顯示,9組酵母組合在DDO培養(yǎng)基上均長出白色菌落,表明9組質(zhì)粒均成功轉(zhuǎn)入酵母菌株;在QDO及QDO/X/A培養(yǎng)基上,陰性和空白對照均無菌斑,陽性對照以及7個酵母組合均能正常生長,且可轉(zhuǎn)變?yōu)樗{色(圖4)。因此,德陽柿SOC1蛋白與AGL14、JOINTLESS、NOVEIN、GL2、UBC7、NBS、MIOX均可發(fā)生互作。
2.5 雙分子熒光互補(BiFC)
為驗證DdSOC1與7個候選互作蛋白在植物體內(nèi)的互作關系,將DdSOC1和候選互作蛋白分別構(gòu)建BiFC載體pSPYNE(NE)和pSPYCE(CE),并在煙草細胞中共注射后觀察YFP熒光信號。結(jié)果(圖5)顯示,7個組合中,JOINTLESS-cYFP+SOC1-nYFP在煙草細胞的細胞核、膜中發(fā)出較強烈的黃色熒光;AGL14-cYFP+Dd-SOC1-nYFP組合在細胞核中發(fā)出黃色熒光;其他組合在細胞膜上顯示黃色熒光。以上情況表明DdSOC1與7個候選互作蛋白在植物體內(nèi)均存在互作關系。
2.6 DdSOC1及互作蛋白基因在德陽柿中的表達情況
探究了蕾期1年生、2年生不同性狀(已開花、未開花)德陽柿實生苗幼葉(頂芽附近葉片)、成葉(遠離頂芽的成年葉)中DdSOC1及互作蛋白基因的表達情況。試驗結(jié)果(圖6)顯示,與未開花實生苗相比,1年生已開花德陽柿實生苗的幼葉中SOC1、AGL14、NOVEIN、GL2、UBC7、NBS的表達量較成葉中高,而MIOX在幼葉的表達量則低于成葉;2年生已開花德陽柿實生苗中,幼葉中SOC1、NOVEIN表達量較成葉低,而其他基因(GL2、UBC7、NBS、AGL14、JOINTLESS)的表達量在幼葉中高于成葉;2年生未開花實生苗中,幼葉中SOC1表達量略低于成葉,其他基因(GL2、AGL14、NOVEIN、JOINTLESS、UBC7、NBS、MIOX)在幼葉中的表達量均高于成葉。
3 討 論
本研究中筆者克隆出了DdSOC1基因,預測了DdSOC1蛋白的等電點及分子質(zhì)量等理化性質(zhì)。進化樹分析表明,DdSOC1蛋白與擬南芥AtSOC1、水稻OsSOC1親緣關系較遠,與歐洲葡萄VvSOC1、茶CsSOC1、中華獼猴桃AcSOC1等親緣關系較近,與同屬君遷子DlSOC1相似性最高,這表明SOC1在木本植物上進化較為保守。DdSOC1的表達特征結(jié)果顯示,在整個成花過程中,葉、芽中DdSOC1表達量分別是逐漸升高和逐漸降低,莖中DdSOC1表達量先降低后升高;幼苗期DdSOC1在芽中表達量最高,蕾期在葉中表達量最高,花期在莖中表達量最高。以上結(jié)果表明,DdSOC1整合了來自葉片的開花信號,以實現(xiàn)營養(yǎng)生長向生殖生長過渡的階段,而不是直接調(diào)控花器官的發(fā)育,這與歐洲葡萄(V. vinifera)、竹子(Bambusa oldhamii)、白梨(Pyrus bretschneideri)、荔枝(Litchi chinensis)的研究結(jié)果較為相似[20-23]。
在前人已探明的SOC1調(diào)控植物開花時間的網(wǎng)絡中,CO、FT、FLC、SVP、DELLA蛋白、AGL24蛋白及LFY是重要的調(diào)控因子。其中,SOC1與AGL24在植物莖頂端分生組織中相互作用形成復合物,然后結(jié)合在LFY啟動子上激活其表達從而完成開花誘導[24-27]。明晰DdSOC1的成花調(diào)控網(wǎng)絡,對探究DdSOC1調(diào)控德陽柿短童期分子機制具有重要意義。本研究基于富平尖柿cDNA核次級文庫對DdSOC1進行互作蛋白的篩選,共篩選得到7個互作蛋白。Y2H和BiFC試驗結(jié)果均驗證了DdSOC1與7個互作蛋白之間存在互作關系。此外,GL2-cYFP + SOC1-nYFP、NOVEIN-cYFP + SOC1-nYFP、JOINTLESS-cYFP + SOC1-nYFP三個組合熒光強度較高,表明DdSOC1與這3個互作蛋白(GL2、NOVEIN、JOINTLESS)互作關系較緊密。后續(xù)可以通過Co-IP或Pull-down蛋白試驗進行進一步驗證。
為了進一步探究DdSOC1及其互作蛋白在德陽柿短童期中的作用,測定了DdSOC1基因在1年生和2年生德陽柿實生苗葉片中的表達量。德陽柿短童期現(xiàn)象在德陽柿種內(nèi)也存在差異,即存在開花和未花兩種性狀,因此本研究中選取蕾期的葉片作為試驗材料。在1年生德陽柿中,已開花實生苗幼葉SOC1表達量比成葉高,而在未開花實生苗中幼葉SOC1表達量比成葉低,這表明SOC1對德陽柿開花有著積極影響。同樣地,AGL14、JOINTLESS、NOVEIN、GL2、UBC7、NBS也表現(xiàn)出與SOC1相似的表達規(guī)律,即在1年生已開花的德陽柿的幼葉中高表達,這說明以上6個互作蛋白可能對德陽柿短童期具有正調(diào)控作用;而MIOX在1年生開花德陽柿實生苗幼葉中低表達,這說明其對德陽柿開花可能有阻遏作用。2年生實生苗,SOC1表達量在不同性狀的實生苗中差異不大,而AGL14、JOINTLESS、GL2、UBC7在開花實生苗中的表達量高于未開花實生苗。此外,前人研究發(fā)現(xiàn),AGL14通過促進LFY和AP1的表達使擬南芥出現(xiàn)早花表型[28],AGL14也參與擬南芥花衰老方面的調(diào)節(jié)[29];JOINTLESS為典型的MADS-box基因,與花序分生組織發(fā)育有著密切關系,如在番茄中正調(diào)控番茄花序的分支和數(shù)量[30-31];GL2作為GL2-zip家族轉(zhuǎn)錄因子通過與ZIM結(jié)構(gòu)域蛋白CsJAZ1相互作用,進而調(diào)控延遲黃瓜雄花的開花時間[32];MIOX參與了晚熟橙花和葉片的發(fā)育過程[33];轉(zhuǎn)錄組學分析表明,NBS在早開花紫苜蓿中高表達[34],而目前并未有關于NOVEIN、UBC7參與植物成花調(diào)控的報道。綜上,本研究中篩選得到7個互作蛋白,AGL14、JOINTLESS、GL2、NBS可能正調(diào)控德陽柿短童期性狀,MIOX可能有延遲開花的作用,而NOVEIN、UBC7可能不參與德陽柿的成花調(diào)控。
4 結(jié) 論
本研究從柿中克隆分離出DdSOC1基因,其序列在木本植物中進化較為保守;DdSOC1可能整合了來自葉片的開花信號,以此實現(xiàn)營養(yǎng)生長向生殖生長的過渡;篩選得到了DdSOC1的7個互作蛋白;AGL14、JOINTLESS、GL2、NBS可能正調(diào)控促進德陽柿開花,MIOX可能有延遲開花的作用,而NOVEIN、UBC7可能不參與德陽柿成花調(diào)控。
參考文獻References:
[1] ZHANG Y F,YANG Y,GUO J,HU C Q,ZHU R S. Taxonomic status of Deyangshi based on chromosome number and SRAP markers[J]. Scientia Horticulturae,2016,207:57-64.
[2] 胡杰. 部分柿屬種形態(tài)學研究與染色體倍性鑒定[D].楊凌:西北農(nóng)林科技大學,2022.
HU Jie. Morphological identification and chromosomal ploidy identification of some persimmon species[D]. Yangling:Northwest A amp; F University,2022.
[3] 楚樂樂,劉海強,盛星星,鄭瑋璇,龔贊,胡春根,張金智. 果樹成花轉(zhuǎn)變途徑與調(diào)控研究進展[J]. 植物科學學報,2022,40(2):281-290.
CHU Lele,LIU Haiqiang,SHENG Xingxing,ZHENG Weixuan,GONG Zan,HU Chungen,ZHANG Jinzhi. Research progress on the pathways and regulation of flowering transformation in fruit trees[J]. Plant Science Journal,2022,40(2):281-290.
[4] MA J J,CHEN X,SONG Y T,ZHANG G F,ZHOU X Q,QUE S P,MAO F,PERVAIZ T,LIN J X,LI Y,LI W,WU H X,NIU S H. MADS-box transcription factors MADS11 and DAL1 interact to mediate the vegetative-to-reproductive transition in pine[J]. Plant Physiology,2021,187(1):247-262.
[5] 張平賢,張青林,徐莉清,郭大勇,羅正榮. 部分柿屬植物的早花現(xiàn)象觀察[J]. 落葉果樹,2017,49(3):24-26.
ZHANG Pingxian,ZHANG Qinglin,XU Liqing,GUO Dayong,LUO Zhengrong. Observation on early flowering of some persimmon plants[J]. Deciduous Fruits,2017,49(3):24-26.
[6] PARCY F. Flowering:A time for integration[J]. The International Journal of Developmental Biology,2005,49(5/6):585-593.
[7] SIMPSON G G,DEAN C. Arabidopsis,the Rosetta stone of flowering time?[J]. Science,2002,296(5566):285-289.
[8] 孫曉茜,戴洪義,張玉剛. 柱型蘋果MADS-box家族的2個同源基因克隆與生物信息學分析[J]. 華北農(nóng)學報,2012,27(2):50-54.
SUN Xiaoqian,DAI Hongyi,ZHANG Yugang. Cloning and bioinformatic analysis of 2 homologous genes of MADS-box in columnar apple[J]. Acta Agriculturae Boreali-Sinica,2012,27(2):50-54.
[9] 蘇文龍,劉程,蘇哲,岳彩云,王曉霞,樊金會. 毛白楊形成層中4種MADS-box基因的克隆和序列分析[J]. 分子植物育種,2015,13(3):653-657.
SU Wenlong,LIU Cheng,SU Zhe,YUE Caiyun,WANG Xiaoxia,F(xiàn)AN Jinhui. Cloning and sequence analysis of four MADS-box genes from cambium of Populus tomentosa[J]. Molecular Plant Breeding,2015,13(3):653-657.
[10] 黃曉婧,張珺,夏惠,鄧群仙,王進,呂秀蘭,梁東. 葡萄MADS-box轉(zhuǎn)錄因子家族全基因組鑒定及表達分析[J]. 園藝學報,2019,46(10):1882-1896.
HUANG Xiaojing,ZHANG Jun,XIA Hui,DENG Qunxian,WANG Jin,Lü Xiulan,LIANG Dong. Genome-wide identification and expression analysis of the MADS-box gene family in Vitis vinifera[J]. Acta Horticulturae Sinica,2019,46(10):1882-1896.
[11] 賀新興,楊杰,高錢輝,佟曉楠,張曉媛,李興濤. 臍橙SOC1基因的克隆及其在臍橙花發(fā)育過程中的表達分析[J]. 分子植物育種,2022,20(15):4948-4957.
HE Xinxing,YANG Jie,GAO Qianhui,TONG Xiaonan,ZHANG Xiaoyuan,LI Xingtao. Cloning and expression analysis of SOC1 gene during the development of navel orange flower[J]. Molecular Plant Breeding,2022,20(15):4948-4957.
[12] MAPLE R,ZHU P,HEPWORTH J,WANG J W,DEAN C. Flowering time:From physiology,through genetics to mechanism[J]. Plant Physiology,2024,195(1):190-212.
[13] YU Y C,QIAO L F,CHEN J C,RONG Y H,ZHAO Y H,CUI X K,XU J P,HOU X M,DONG C H. Arabidopsis REM16 acts as a B3 domain transcription factor to promote flowering time via directly binding to the promoters of SOC1 and FT[J]. The Plant Journal,2020,103(4):1386-1398.
[14] DENG Q L,WANG Y D,F(xiàn)ENG J J,WEI D Y,WANG Z M,TANG Q L. Brassica juncea BjuWRKY71-1 accelerates flowering by regulating the expression of SOC1[J]. Chinese Journal of Biotechnology,2024,40(4):1017-1028.
[15] JIN Z P,YU X,PEI Y X. Ectopic expression of AtSOC1 gene driven by the inducible promoter rd29A,causes early flowering in Chrysanthemum[J]. Scientia Horticulturae,2020,261:109051.
[16] 齊聯(lián)聯(lián),宿強,張珂. SOC1調(diào)控植物開花時間的分子機制[J]. 草業(yè)科學,2022,39(1):149-160.
QI Lianlian,SU Qiang,ZHANG Ke. Molecular mechanism of flowering time regulate by SOC1[J]. Pratacultural Science,2022,39(1):149-160.
[17] LUO X M,LIU B Y,XIE L,WANG K,XU D A,TIAN X L,XIE L N,LI L L,YE X G,HE Z H,XIA X C,YAN L L,CAO S H. The TaSOC1-TaVRN1 module integrates photoperiod and vernalization signals to regulate wheat flowering[J]. Plant Biotechnology Journal,2024,22(3):635-649.
[18] LI X,SHEN C W,CHEN R X,SUN B,LI D H,GUO X L,WU C H,KHAN N,CHEN B H,YUAN J P. Function of BrSOC1b gene in flowering regulation of Chinese cabbage and its protein interaction[J]. Planta,2023,258(1):21.
[19] DONG X,ZHANG L P,TANG Y H,YU D M,CHENG F,DONG Y X,JIANG X D,QIAN F M,GUO Z H,HU J Y. Arabidopsis AGAMOUS-LIKE16 and SUPPRESSOR OF CONSTANS1 regulate the genome-wide expression and flowering time[J]. Plant Physiology,2023,192(1):154-169.
[20] 劉丹,孫欣,慕茜,吳偉民,章鎮(zhèn),房經(jīng)貴. 葡萄花芽發(fā)育相關基因在不同節(jié)位芽中的表達分析[J]. 中國農(nóng)業(yè)科學,2015,48(10):2007-2016.
LIU Dan,SUN Xin,MU Qian,WU Weimin,ZHANG Zhen,F(xiàn)ANG Jinggui. Analysis of expression levels of floral genes in the buds on different branch nodes of grapevine[J]. Scientia Agricultura Sinica,2015,48(10):2007-2016.
[21] HOU D,LI L,MA T F,PEI J L,ZHAO Z Y,LU M Z,WU A M,LIN X C. The SOC1-like gene BoMADS50 is associated with the flowering of Bambusa oldhamii[J]. Horticulture Research,2021,8(1):133.
[22] LIU Z,WU X P,CHENG M Y,XIE Z H,XIONG C L,ZHANG S L,WU J Y,WANG P. Identification and functional characterization of SOC1-like genes in Pyrus bretschneideri[J]. Genomics,2020,112(2):1622-1632.
[23] SHI Y Y,ZHANG S W,GUI Q L,QING H W,LI M,YI C X,GUO H Q,CHEN H B,XU J Z,DING F. The SOC1 gene plays an important role in regulating litchi flowering time[J]. Genomics,2024,116(2):110804.
[24] LEE J,LEE I. Regulation and function of SOC1,a flowering pathway integrator[J]. Journal of Experimental Botany,2010,61(9):2247-2254.
[25] LIU C,CHEN H Y,ER H L,SOO H M,KUMAR P P,HAN J H,LIOU Y C,YU H. Direct interaction of AGL24 and SOC1 integrates flowering signals in Arabidopsis[J]. Development,2008,135(8):1481-1491.
[26] KHAN M R,KHAN I U,ALI G M. MPF2-like MADS-box genes affecting expression of SOC1 and MAF1 are recruited to control flowering time[J]. Molecular Biotechnology,2013,54(1):25-36.
[27] 蔣煒,周雯文,李朝闖,閆凱,王宇,王志敏,宋明,湯青林. 青花菜開花促進因子AGL19與整合子AGL24和SOC1的互作研究[J]. 園藝學報,2017,44(10):1905-1913.
JIANG Wei,ZHOU Wenwen,LI Zhaochuang,YAN Kai,WANG Yu,WANG Zhimin,SONG Ming,TANG Qinglin. Interactions of flowering promoting factor AGL19 with integrator factors AGL24 and SOC1 in Brassica oleracea var. italica[J]. Acta Horticulturae Sinica,2017,44(10):1905-1913.
[28] PéREZ-RUIZ R V,GARCíA-PONCE B,MARSCH-MARTíNEZ N,UGARTECHEA-CHIRINO Y,VILLAJUANA-BONEQUI M,DE FOLTER S,AZPEITIA E,DáVILA-VELDERRAIN J,CRUZ-SáNCHEZ D,GARAY-ARROYO A,DE LA PAZ SáNCHEZ M,ESTéVEZ-PALMAS J M,áLVAREZ-BUYLLA E R. XAANTAL2 (AGL14) is an important component of the complex gene regulatory network that underlies Arabidopsis shoot apical meristem transitions[J]. Molecular Plant,2015,8(5):796-813.
[29] CHEN W H,LIN P T,HSU W H,HSU H F,LI Y C,TSAO C W,HSU M C,MAO W T,YANG C H. Regulatory network for forever young flower-like genes in regulating Arabidopsis flower senescence and abscission[J]. Communications Biology,2022,5(1):662.
[30] HUERGA-FERNáNDEZ S,DETRY N,ORMAN-LIGEZA B,BOUCHé F,HANIKENNE M,PéRILLEUX C. JOINTLESS maintains inflorescence meristem identity in tomato[J]. Plant amp; Cell Physiology,2024,65(7):1197-1211.
[31] 王翔,尹鈞. 番茄花柄離區(qū)發(fā)育基因JOINTLESS及互作蛋白基因的功能研究[J]. 園藝學報,2011,38(4):701-708.
WANG Xiang,YIN Jun. Functional studies of JOINTLESS and its interacting MADS-domain proteins in tomato[J]. Acta Horticulturae Sinica,2011,38(4):701-708.
[32] CAI Y L,BARTHOLOMEW E S,DONG M M,ZHAI X L,YIN S,ZHANG Y Q,F(xiàn)ENG Z X,WU L C,LIU W,SHAN N,ZHANG X,REN H Z,LIU X W. The HD-ZIP IV transcription factor GL2-LIKE regulates male flowering time and fertility in cucumber[J]. Journal of Experimental Botany,2020,71(18):5425-5437.
[33] ALóS E,REY F,GIL J V,RODRIGO M J,ZACARIAS L. Ascorbic acid content and transcriptional profiling of genes involved in its metabolism during development of petals,leaves,and fruits of orange (Citrus sinensis cv. Valencia Late)[J]. Plants,2021,10(12):2590.
[34] MA D M,LIU B,GE L Q,WENG Y Y,CAO X H,LIU F,MAO P S,MA X Q. Identification and characterization of regulatory pathways involved in early flowering in the new leaves of alfalfa (Medicago sativa L.) by transcriptome analysis[J]. BMC Plant Biology,2021,21(1):8.
收稿日期:2024-09-26 接受日期:2024-12-04
基金項目:國家重點研發(fā)計劃(2022YFD2200403);廣西自然科學基金項目(2021GXNSFBA196032)
作者簡介:萬建琦,在讀碩士研究生,研究方向為果樹育種與生物技術。E-mail:wanjianqi0101@qq.com
*通信作者Author for correspondence. E-mail:guanchangfei@nwafu.edu.cn