摘要
本文试验的出发点是一个传统的生态学问题。本文在立足于生态学这样一个基本生态问题—植物如何适应光周期现象,而后延伸到了光周期适应物种是如何适应这种光周期现象而进行程序性发育?光照和温度是自然界中两大最基本的生态因子。从根本上讲,物种(尤其是植物)的进化就是适应光温条件的一个过程。中国地域辽阔,纬度跨越很大,因此在农业生产和品种选育过程中,各个地方逐渐形成了自己的栽培品种,而这些栽培品种无非就是单一适应地方光温条件。
本文所用材料为自贡冬豆(Glycine max[L.]Merr.),大豆中晚熟品种,短日植物,产于四川自贡地区,对光周期反应敏感。
在室内模拟纬度变化条件下的光周期变化,在不同光周期条件下比较观察自贡冬豆的生长形态,我们发现自贡冬豆存在三种典型的形态:持续短日(12h/d)条件下的正常花;持续长日(16h/d)完全营养生长;短日/长日条件下花序呈现(自上而下)营养芽、逆转花和正常花混合分布的现象。这些现象说明了四个方面的问题:第一适宜的光周期条件是自贡冬豆成功地由营养生长向生殖生长转变的必须生态因子;第二自贡冬豆由营养生长向生殖生长转变所需光周期条件是连续的;第三维持自贡冬豆开花的信号具有数量特征;第四这些特征同模式植物拟南芥生长发育转变所必须的AP1(APETALA1)花分生组织特征基因行使功能赋予的特征相似。
APETALA1基因是MADS—box基因家族中的成员,它们具有高度保守的结构域在植物的发育过程中功能又很高的保守性。根据这些特征结合双子叶植物碱基使用的保守性,我们设计了兼并引物并成功调取了APETALA1在大豆中的同源类似基因(homolog)GmAPETALA1。在碱基水平和蛋白水平上,GmAPETALA1同APETALA1的相似性分别为45%和56.08%。
RT—PCR实验证明在长日条件,GmAPETALA1在顶端分生组织(shoot apicalmeristem)表达处于很低的水平,并且表达水平不会随着长日条件的改变而改变;在短日条件下GmAPETALA1在顶端分生组织中的表达随着短日条件的延长而升高并且在花器官中的表达处于很高的水平;不论在长短日条件下,在其它组织中都没有表达。
为了分析APETALA1在大豆中的表达,我们比较分析了几种不同的方法制作核酸探针的效率并发现利用PCR的方法制作ssDNA探针与利用转录的方法制作的RNA探针以及PCR方法制作的dsDNA探针相比较可以获得更高产量。
The experiments included in this paper are derived from a general ecological question.Based on photoperiodism,a question was asked that how plant species adapt to photoperiod and develop stereotypcially and properly?Light and temperature are two basally ecological factors. Intrincically,species(especially plant) evolution is a progress to adapt to preferential light and temperature.In china,covered widly,many cultival species are those narrow light- and temperature-adaptation species.
The experimental plant is Zigongdongdou(Glycine max[L.]Merr.), which is a cultival species,characterized with late maturation,short day-induced reproduction and high sensitivity to photoperiod.
Previous experiments showed that inflorescences of Zigongdongdou took on three kinds of typical phenotypes,including normal flowers under continuous short-day light(12h/d);the whole vegetative state of shoot apical meristem under continuous long-day light(16h/d) and fused phenotypes with apical-to-basal vegetative leaves、reversed flowers and normal flowers when plants were transfer from short day(enough time to induce floral initiation) to long day condition.These results suggest that correct photoperiod is necessary for successful transition of plant development stage from vegetative stage to reproductive stage;the needed photoperiod is continuous;signals maintenning floral transition is quantitative and these phenotypes caused by variable photoperiod is siminar to those of manipulating functional AP1 conferring to Arabidopsis.
APETALA1 is a member of MADS-box family with conserved domains for plant development.In combination with properties of dicotyledons preferring to bases,degenerate primers were designed.Using the pair of primers,GmAPETALA1,homolog of APETALA1 in soybean was cloned. The similarity of the cDNA and protein sequence to those of APETALA1 was 45%and 56.08%respectively.
RT-PCR was conducted and showed that at long-day condition, GmAPETALA1 expression level was very low and kept low level in shoot apical meristem even increasing long-day treatment;at short-day condition,the expression level increased with more short-day treatment and have a higher level in floral organs;its expression did not expand to other tissues no matter at what conditions.
For more expriments,we synthesized DIG-labelled probes using different protocols and checked their synthesis efficience.The results showed that PCR-based synthesis of ssDNA had a higher efficience than transcription-based synthesis RNA probes and PCR-based synthesis dsDNA probes.
引文
Abe,M.,Kobayashi,Y,Yamamoto,S.,Daimon,Y,Yamaguchi,A.,Ikeda,Y,Ichinoki,H.,Notaguchi,M.,Goto,K.,and Araki,T.(2005).FD,a bZIP protein mediating signals from the floral pathway integrator FT at the shoot apex.Science 309,1052-1056.
An,H.,Roussot,C,Suarez-Lopez,P.,Corbesier,L.,Vincent,C,Pineiro,M.,Hepworth,S.,Mouradov,A.,Justin,S.,Turnbull,C,and Coupland,G.(2004).CONSTANS acts in the phloem to regulate a systemic signal that inducesphotoperiodic flowering of Arabidopsis.Development 131,3615-3626.
Araki,T.(2001).Transition from vegetative to reproductive phase.Curr Opin Plant Biol 4,63-68.
Baurle,I.,and Laux,T.(2003).Apical meristems: the plant's fountain of youth.Bioessays 25,961-970.
Bemis, S.M., and Torii, K.U.(2006).Autonomy of cell proliferation and developmental programs during Arabidopsis aboveground organ morphogenesis.Dev Biol.
Berbel,A.,Navarro,C.,Ferrandiz,C,Canas,L.A.,Madueno,F.,and Beltran,J.P.(2001).Analysis of PEAM4,the pea API functional homologue,supports a model for API-like genes controlling both floral meristem and floral organ identity in different plant species.Plant J 25,441-451.
Bertrand,C,Bergounioux,C,Domenichini,S.,Delarue,M.,and Zhou,D.X.(2003).Arabidopsis histone acetyltransferase AtGCN5 regulates the floral meristem activity through the WUSCHEL/AGAMOUS pathway.J Biol Chem 278,28246-28251.
Bhalla,P.L.,and Singh,M.B.(2006).Molecular control of stem cell maintenance in shoot apical meristem.Plant Cell Rep 25,249-256.
Blazquez,M.A.(1997).Illuminating flowers: CONSTANS induces LEAFY expression.Bioessays 19,277-279.
Blazquez,M.A.,Soowal,L.N.,Lee,I.,and Weigel,D.(1997).LEAFY expression and flower initiation in Arabidopsis.Development 124,3835-3844.
Bowman,J.L.,and Eshed,Y.(2000).Formation and maintenance of the shoot apical meristem.Trends Plant Sci 5,110-115.
Brand,U.,Hobe,M.,and Simon,R.(2001).Functional domains in plant shoot meristems.Bioessays 23,134-141.
Carles,C.C,and Fletcher,J.C.(2003).Shoot apical meristem maintenance: the art of a dynamic balance.Trends Plant Sci 8,394-401.
Carles,C.C,Lertpiriyapong,K.,Reville,K., and Fletcher,J.C.(2004).The ULTRAPETALA1 gene functions early in Arabidopsis development to restrict shoot apical meristem activity and acts through WUSCHEL to regulate floral meristem determinacy.Genetics 167,1893-1903.
Carles,C.C,Choffnes-Inada,D.,Reville,K.,Lertpiriyapong,K.,and Fletcher,J.C.(2005).ULTRAPETALA1 encodes a SAND domain putative transcriptional regulator that controls shoot and floral meristem activity in Arabidopsis.Development 132,897-911.
Carraro,N.,Peaucelle,A.,Laufs,P,and Traas,J.(2006).Cell differentiation and organ initiation at the shoot apical meristem.Plant Mol Biol 60,811-826.
Cho,S.,Jang,S.,Chae,S.,Chung,K.M.,Moon,Y.H.,An,G,and Jang,S.K.(1999).Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain.Plant Mol Biol 40,419-429.
Choi,K.,Kim,S.,Kim,S.Y.,Kim,M.,Hyun,Y,Lee,H.,Choe,S.,Kim,S.G,Michaels,S.,and Lee,I.(2005).SUPPRESSOR OF FRIGIDA3 encodes a nuclear ACTIN-RELATED PROTEIN6 required for floral repression in Arabidopsis.Plant Cell 17,2647-2660.
Clark,S.E.(2001a).Meristems: start your signaling.Curr Opin Plant Biol 4,28-32.
Clark,S.E.(2001b).Cell signalling at the shoot meristem.Nat Rev Mol Cell Biol 2,276-284.
Clark,S.E.,Running,M.R,and Meyerowitz,E.M.(1993).CLAVATAl,a regulator of meristem and flower development in Arabidopsis.Development 119,397-418.
Clark,S.E.,Williams,R.W.,and Meyerowitz,E.M.(1997).The CLAVATAl gene encodes a putative receptor kinase that controls shoot and floral meristem size in Arabidopsis.Cell 89,575-585.
Clark,S.E.,Jacobsen,S.E.,Levin,J.Z.,and Meyerowitz,E.M.(1996).The CLAVATA and SHOOT MERISTEMLESS loci competitively regulate meristem activity in Arabidopsis.Development 122,1567-1575.
Doerner,P.(1999).Shoot meristems: Intercellular signals keep the balance.Curr Biol 9,R377-380.
Endrizzi,K.,Moussian,B.,Haecker,A.,Levin,J.Z.,and Laux,T.(1996).The SHOOT MERISTEMLESS gene is required for maintenance of undifferentiated cells in Arabidopsis shoot and floral meristems and acts at a different regulatory level than the meristem genes WUSCHEL and ZWILLE.Plant J 10,967-979.
Fletcher,J.C.(2002).Shoot and floral meristem maintenance in arabidopsis.Annu Rev Plant Biol 53,45-66.
Fletcher,J.C,and Meyerowitz,E.M.(2000).Cell signaling within the shoot meristem.Curr Opin Plant Biol 3,23-30.
Gallois,J.L.,Nora,F.R.,Mizukami,Y.,and Sablowski,R.(2004).WUSCHEL induces shoot stem cell activity and developmental plasticity in the root meristem.Genes Dev 18,375-380.
Golz,J.F.(2006).Signalling between the shoot apical meristem and developing lateral organs.Plant Mol Biol 60,889-903.
Gregis,V,Sessa,A.,Colombo,L.,and Kater,M.M.(2006).AGL24,SHORT VEGETATIVE PHASE,and APETALA1 redundantly control AGAMOUS during early stages of flower development in Arabidopsis.Plant Cell 18,1373-1382.
Gustafson-Brown,C,Savidge,B.,and Yanofsky,M.F.(1994).Regulation of the arabidopsis floral homeotic gene APETALA1.Cell 76,131-143.
Hempel,F.D.,Zambryski,PC,and Feldman,L.J.(1998).Photoinduction of flower identity in vegetatively biased primordia.Plant Cell 10,1663-1676.
Hong,R.L.,Hamaguchi,L.,Busch,M.A.,and Weigel,D.(2003).Regulatory elements of the floral homeotic gene AGAMOUS identified by phylogenetic footprinting and shadowing.Plant Cell 15,1296-1309.
Huala,E.,and Sussex,I.M.(1992).LEAFY Interacts with Floral Homeotic Genes to Regulate Arabidopsis Floral Development.Plant Cell 4,901-913.
Jeong,S.,and Clark,S.E.(2005).Photoperiod regulates flower meristem development in Arabidopsis thaliana.Genetics 169,907-915.
Jeong,S.,Trotochaud,A.E.,and Clark,S.E.(1999).The Arabidopsis CLAVATA2 gene encodes a receptor-like protein required for the stability of the CLAVATA1 receptor-like kinase.Plant Cell 11,1925-1934.
Jurgens,G,Maye r,U.,Busch,M.,Lukowitz,W.,and Laux,T.(1995).Patternformation in the Arabidopsis embryo: a genetic perspective.Philos Trans R Soc Lond B Biol Sci 350,19-25.
Kaya,H.,Shibahara,K.I.,Taoka,K.I.,Iwabuchi,M.,Stillman,B.,and Araki,T.(2001).FASCIATA genes for chromatin assembly factor-1 in arabidopsis maintain the cellular organization of apical meristems.Cell 104,131-142.
Kayes,J.M.,and Clark,S.E.(1998).CLAVATA2,a regulator of meristem and organ development in Arabidopsis.Development 125,3843-3851.
Kelly,A.J.,Bonnlander,M.B.,and Meeks-Wagner,D.R.(1995).NFL,the tobacco homolog of FLORICAULA and LEAFY,is transcriptionally expressed in both vegetative and floral meristems.Plant Cell 7,225-234.
Komeda,Y.(2004).Genetic regulation of time to flower in Arabidopsis thaliana.Annu Rev Plant Biol 55,521-535.
Larsson,A.S.,Landberg,K.,and Meeks-Wagner,D.R.(1998).The TERMINAL FLOWER2 (TFL2) gene controls the reproductive transition and meristem identity in Arabidopsis thaliana.Genetics 149,597-605.
Laux,T.,Mayer,K.F.,Berger,J.,and Jurgens,G (1996).The WUSCHEL gene is required for shoot and floral meristem integrity in Arabidopsis.Development 122,87-96.
Lee,I.,Wolfe,D.S.,Nilsson,O.,and Weigel,D.(1997).A LEAFY co-regulator encoded by UNUSUAL FLORAL ORGANS.Curr Biol 7,95-104.
Lenhard,M.,and Laux,T.(1999).Shoot meristem formation and maintenance.Curr Opin Plant Biol 2,44-50.
Lenhard,M.,and Laux,T.(2003).Stem cell homeostasis in the Arabidopsis shoot meristem is regulated by intercellular movement of CLAVATA3 and its sequestration by CLAVATA1.Development 13 0,3163-3173.
Lenhard,M.,Bohnert,A.,Jurgens,G,and Laux,T.(2001).Termination of stem cell maintenance in Arabidopsis floral meristems by interactions between WUSCHEL and AGAMOUS.Cell 105,805-814.
Liljegren,S.J.,Gustafson-Brown,C,Pinyopich,A.,Ditta,G.S.,and Yanofsky,M.F.(1999).Interactions among APETALA1,LEAFY,and TERMINAL FLOWER1 specify meristem fate.Plant Cell 11,1007-1018.
Litt, A., and Irish, V.F.(2003).Duplication and diversification in the APETALA1/FRUITFULL floral homeotic gene lineage: implications for the evolution of floral development.Genetics 165,821-833.
Lohmann,J.U.,Hong,R.L.,Hobe,M.,Busch,M.A.,Parcy,F.,Simon,R.,and Weigel,D.(2001).A molecular link between stem cell regulation and floral patterning in Arabidopsis.Cell 105,793-803.
Lowman,A.C.,and Purugganan,M.D.(1999).Duplication of the Brassica oleracea APETALA1 floral homeotic gene and the evolution of domesticated cauliflower.J Hered 90,514-520.
Mandel,M.A.,Gustafson-Brown,C,Savidge,B.,and Yanofsky,M.F.(1992).Molecular characterization of the Arabidopsis floral homeotic gene APETALA1.Nature 360,273-277.
Mayer,K.F.,Schoof,H.,Haecker,A.,Lenhard,M.,Jurgens,G,and Laux,T.(1998).Role of WUSCHEL in regulating stem cell fate in the Arabidopsis shoot meristem.Cell 95,805-815.
McDaniel,C.N.,Singer,S.R.,and Smith,S.M.(1992).Development states associated with the floral transition.Dev Biol 153,59-69.
Mena,M.,Mandel,M.A.,Lerner,D.R.,Yanofsky,M.R,and Schmidt,R.J.(1995).A characterization of the MADS-box gene family in maize.Plant J 8,845-854.
Mizukami,Y,and Ma,H.(1997).Determination of Arabidopsis floral meristem identity by AGAMOUS.Plant Cell 9,393-408.
Mouradov,A.,Glassick,T.,Hamdorf,B.,Murphy,L.,Fowler,B.,Maria,S.,and Teasdale, R.D.(1998).NEEDLY, a Pinus radiata ortholog of FLORICAULA/LEAFY genes,expressed in both reproductive and vegetative meristems.Proc Natl Acad Sci U S A 95,6537-6542.
Ng,M.,and Yanofsky,M.F.(2001).Activation of the Arabidopsis B class homeotic genes by APETALA1.Plant Cell 13,739-753.
Okamuro,J.K.,Szeto,W.,Lotys-Prass,C,and Jofuku,K.D.(1997).Photo and hormonal control of meristem identity in the Arabidopsis flower mutants apetala2 and apetalal.Plant Cell 9,37-47.
Okamuro,J.K.,den Boer,B.G.,Lotys-Prass,C,Szeto,W.,and Jofuku,K.D.(1996).Flowers into shoots: photo and hormonal control of a meristem identity switch in Arabidopsis.Proc Natl Acad Sci U S A 93,13831-13836.
Paquette,A.J.,and Benfey,P.N.(2001).Axis formation and polarity in plants.Curr Opin Genet Dev 11,405-409.
Parcy,R,Bomblies,K.,and Weigel,D.(2002).Interaction of LEAFY,AGAMOUS and TERMINAL FLOWER1 in maintaining floral meristem identity in Arabidopsis.Development 129,2519-2527.
Pnueli,L.,Carmel-Goren,L.,Hareven,D.,Gutfinger,T.,Alvarez,J.,Ganal,M.,Zamir,D.,and Lifschitz,E.(1998).The SELF-PRUNING gene of tomato regulates vegetative to reproductive switching of sympodial meristems and is the ortholog of CEN andTFLl.Development 125,1979-1989.
Pouteau,S.,Nicholls,D.,Tooke,R,Coen,E.,and Battey,N.(1997).The induction and maintenance of flowering in Impatiens.Development 124,3343-3351.
Pouteau,S.,Nicholls,D.,Tooke,R,Coen,E.,and Battey,N.(1998).Transcription pattern of a FIM homologue in Impatiens during floral development and reversion.Plant J 14,235-246.
Purugganan,M.D.,Rounsley,S.D.,Schmidt,R.J.,and Yanofsky,M.F.(1995).Molecular evolution of flower development: diversification of the plant MADS-box regulatory gene family.Genetics 140,345-356.
Reeves,P.H.,and Coupland,G (2000).Response of plant development to environment: control of flowering by day length and temperature.Curr Opin Plant Biol 3,37-42.
Rouse,D.T.,Sheldon,C.C.,Bagnall,D.J.,Peacock,W.J.,and Dennis,E.S.(2002).FLC,a repressor of flowering,is regulated by genes in different inductive pathways.Plant J 29,183-191.
Sablowski,R.(2007a).Flowering and determinacy in Arabidopsis.J Exp Bot 58,899-907.
Sablowski,R.(2007b).Flowering and determinacy in Arabidopsis.J Exp Bot.
Salathia,N.,Davis,S.J.,Lynn,J.R.,Michaels,S.D.,Amasino,R.M.,and Millar,A.J.(2006).FLOWERING LOCUS C-dependent and-independent regulation of the circadian clock by the autonomous and vernalization pathways.BMC PlantBiol 6,10.
Schoof,H.,Lenhard,M.,Haecker,A.,Mayer,K.F.,Jurgens,G,and Laux,T.(2000).The stem cell population of Arabidopsis shoot meristems in maintained by a regulatory loop between the CLAVATA and WUSCHEL genes.Cell 100,635-644.
Schultz,E.A.,and Haughn,GW.(1991).LEAFY,a Homeotic Gene That Regulates Inflorescence Development in Arabidopsis.Plant Cell 3,771-781.
Searle,I.,and Coupland,G (2004).Induction of flowering by seasonal changes in photoperiod.Embo J 23,1217-1222.
Searle,I.,He,Y,Turck,R,Vincent,C,Fornara,R,Krober,S.,Amasino,R.A.,and Coupland,G (2006).The transcription factor FLC confers a flowering response to vernalization by repressing meristem competence and systemic signaling in Arabidopsis.Genes Dev 20,898-912.
Sessions,A.,Yanofsky,M.F.,and Weigel,D.(2000).Cell-cell signaling and movement by the floral transcription factors LEAFY and APETALA1.Science 289,779-782.
Sharma,V.K.,Carles,C,and Fletcher,J.C.(2003).Maintenance of stem cell populations in plants.Proc Natl Acad Sci U S A 100 Suppl 1,11823-11829.
Simpson,G.G.(2004).The autonomous pathway: epigenetic and post-transcriptional gene regulation in the control of Arabidopsis flowering time.Curr Opin Plant Biol 7,570-574.
Stone,J.M.,Trotochaud,A.E.,Walker,J.C,and Clark,S.E.(1998).Control of meristem development by CLAVATA1 receptor kinase and kinase-associated protein phosphatase interactions.Plant Physiol 117,1217-1225.
Takada,S.,and Tasaka,M.(2002).Embryonic shoot apical meristem formation in higher plants.J Plant Res 115,411-417.
Taylor,S.A.,Hofer,J.M.,Murfet,I.C.,Sollinger,J.D.,Singer,S.R.,Knox,M.R.,and Ellis,T.H.(2002).PROLIFERATING INFLORESCENCE MERISTEM,a MADS-box gene that regulates floral meristem identity in pea.Plant Physiol 129,1150-1159.
Tooke,F.,Ordidge,M.,Chiurugwi,T.,and Battey,N.(2005).Mechanisms and function of flower and inflorescence reversion.J Exp Bot 56,2587-2599.
Traas,J.,and Bohn-Courseau,I.(2005).Cell proliferation patterns at the shoot apical meristem.Curr Opin Plant Biol 8,587-592.
Trevaskis,B.,Tadege,M.,Hemming,M.N.,Peacock,W.J.,Dennis,E.S.,and Sheldon,C.(2007).Short vegetative phase-like MADS-box genes inhibit floral meristem identity in barley.Plant Physiol 143,225-235.
Trotochaud,A.E.,Jeong,S.,and Clark,S.E.(2000).CLAVATA3,a multimeric ligand for the CLAVATA1 receptor-kinase.Science 289,613-617.
Trotochaud,A.E.,Hao,T.,Wu,G,Yang,Z.,and Clark,S.E.(1999).The CLAVATA1 receptor-like kinase requires CLAVATA3 for its assembly into a signaling complex that includes KAPP and a Rho-related protein.Plant Cell 11,393-406.
Vernoux,T.,Autran,D.,and Traas,J.(2000).Developmental control of cell division patterns in the shoot apex.Plant Mol Biol 43,569-581.
Wang,Q.,Sajja,U.,Rosloski,S.,Humphrey,T.,Kim,M.C.,Bomblies,K.,Weigel,D.,and Grbic,V.(2007).HUA2 caused natural variation in shoot morphology of A.thaliana.Curr Biol 17,1513-1519.
Washburn,C.F.,and Thomas,J.F.(2000).Reversion of flowering in Glycine Max (Fabaceae).Am J Bot 87,1425-1438.
Weigel,D.,and Nilsson,O.(1995).A developmental switch sufficient for flower initiation in diverse plants.Nature 377,495-500.
Weigel,D.,and Clark,S.E.(1996).Sizing Up the Floral Meristem.Plant Physiol 112,5-10.
Weigel,D.,Alvarez,J.,Smyth,D.R.,Yanofsky,M.F.,and Meyerowitz,E.M.(1992).LEAFY controls floral meristem identity in Arabidopsis.Cell 69,843-859.
Wilkinson,M.D.,and Haughn,G.W (1995).UNUSUAL FLORAL ORGANS Controls Meristem Identity and Organ Primordia Fate in Arabidopsis.Plant Cell 7,1485-1499.
Williams,L.,and Fletcher,J.C.(2005).Stem cell regulation in the Arabidopsis shoot apical meristem.Curr Opin Plant Biol 8,582-586.
Wu,C,Ma,Q.,Yam,K.M.,Cheung,MY,Xu,Y,Han,T.,Lam,H.M.,and Chong,K.(2006).In situ expression of the GmNMH7 gene is photoperiod-dependent in a unique soybean (Glycine max [L.]Merr.) flowering reversion system.Planta 223,725-735.
Wurschum,T.,Gross-Hardt,R.,and Laux,T.(2006).APETALA2 regulates the stem cell niche in the Arabidopsis shoot meristem.Plant Cell 18,295-307.
Xu,Y.Y.,and Chong,K.(2005).[Progress.in research on plant stem cell organizer gene WUSCHEL].Zhi Wu Sheng Li Yu Fen Zi Sheng Wu Xue Xue Bao 31,461-468.
Yoo,S.K.,Lee,J.S.,and Ahn,J.H.(2006).Overexpression of AGAMOUS-LIKE 28 (AGL28) promotes flowering by upregulating expression of floral promoters within the autonomous pathway.Biochem Biophys Res Commun 348,929-936.
Yu, H., Ito, T., Wellmer, R, and Meyerowitz, E.M.(2004).Repression of AGAMOUS-LIKE 24 is a crucial step in promoting flower development.Nat Genet 36,157-161.
Zuo,J.,Niu,Q.W.,Frugis,G,and Chua,N.H.(2002).The WUSCHEL gene promotes vegetative-to-embryonic transition in Arabidopsis.Plant J 30,349-359.