Mechanisms underlying green flower formation

Abstract

Green flowers are uncommon in nature, yet they present a unique opportunity to explore the molecular, developmental, and evolutionary principles underlying floral pigmentation. While most species undergo petal degreening during maturation, some retain chlorophyll through suppressed degradation, sustained synthesis, or altered plastid differentiation. Here, we synthesize recent advances in understanding the molecular basis of green flower formation, integrating evidence from plastid biology, chlorophyll metabolism, transcription factor regulation, and floral organ identity genes. Research across diverse taxa reveals that chlorophyll homeostasis in petals is shaped by the interplay of light and hormonal signals, and orchestrated by transcriptional networks. In certain instances, homeotic transformations result in leaf-like characteristics. Naturally occurring variants, as well as engineered lines, offer powerful systems to dissect how developmental programs governing organ identity intersect with pigment metabolism. Green flowers also hold distinct ornamental and cultural value, expanding their relevance beyond ecological function. By tracing progress from morphological observations to multi-omics analyses, we highlight how this field is beginning to uncover shared regulatory frameworks and lineage-specific innovations. In the future, targeted manipulation of key regulatory nodes could enable the precise breeding of stable green blooms, while comparative studies promise deeper insights into how pigment pathways evolve and integrate with broader developmental networks. Understanding these processes will not only enrich floral biology but also enhance our ability to intentionally design and diversify plant phenotypes.

Author contributions

H.G. and Z.H. participated in the conceptualization. X.L., C.H., H.L., Q.S., and S.H. participated in the writing-original draft. X.L., C.H., H.L., Q.S., S.H., Y.Z., G.S., Z.H., and H.G. participated in the writing-review and editing. X.L., H.L., and S.H. participated in the figure preparation. H.G. and Z.H. participated in the research supervision and funding.

Data availability

There are no new data associated with this article.

Conflicts of interest statement

The authors declare no conflicts of interest.

References

[1] Zheng X, Lan J, Yu H, et al. Arabidopsis transcription factor TCP4 represses chlorophyll biosynthesis to prevent petal greening. Plant Commun. 2022; 3: 100309

[2] Zhou S, Ma C, Zhou W, et al. Selection of stable reference genes for qRT-PCR in tree peony ‘Doulv’ and functional analysis of PsCUC3 . Plants. 2024; 13: 1741

[3] Zhou W, Fang L, Gao S, et al. Cloning and functional analysis of PsNAC5 regulating flower color in tree peony ‘Doulü’ . Plant Physiol J. 2024; 60: 311-20

[4] Liao H, Zhang J, Zhang H, et al. Research progress on organ variation in Rosa chinensis . Chin Agric Sci Bull. 2025; 41: 49-55

[5] Ohmiya A, Sasaki K, Nashima K, et al. Transcriptome analysis in petals and leaves of chrysanthemums with different chlorophyll levels. Plant Biol. 2017; 17: 202

[6] Mayak S, Tirosh T, Thompson JE, et al. The fate of ribulose-1,5-bisphosphate carboxylase subunits during development of carnation petals. Plant Physiol Bioch. 1998; 36: 835-41

[7] Xia Y, Chen W, Xiang W, et al. Integrated metabolic profiling and transcriptome analysis of pigment accumulation in Lonicera japonica flower petals during colour-transition . Plant Biol. 2021; 21: 98

[8] Ye Q, Liu F, Feng K, et al. Integrated metabolomics and transcriptome analysis of anthocyanin biosynthetic pathway in Prunus serrulata . Plants. 2025; 14: 114

[9] Zhou N, Yan Y, Wen Y, et al. Integrated transcriptome and metabolome analysis unveils the mechanism of color-transition in Edgeworthia chrysantha tepals . Plant Biol. 2023; 23: 567

[10] Bowman JL, Smyth DR, Meyerowitz EM . Genes directing flower development in Arabidopsis. Plant Cell. 1989; 1: 37-52

[11] Goto K, Meyerowitz EM . Function and regulation of the Arabidopsis floral homeotic gene PISTILLATA . Genes Dev. 1994; 8: 1548-60

[12] Hao Q, Li T, Lu G, et al. Chlorophyllase (PsCLH1) and light-harvesting chlorophyll a/b binding protein 1 (PsLhcb1) and PsLhcb5 maintain petal greenness in Paeonia suffruticosa ‘Lv Mu Yin Yu’ . J Adv Res. 2025; 73: 173-85

[13] Sun T, Yuan H, Cao H, et al. Carotenoid metabolism in plants: the role of plastids. Mol Plant. 2018; 11: 58-74

[14] Nisar N, Li L, Lu S, et al. Carotenoid metabolism in plants. Mol Plant. 2015; 8: 68-82

[15] Liu L, Shao Z, Zhang M, et al. Regulation of carotenoid metabolism in tomato. Mol Plant. 2015; 8: 28-39

[16] Sadali NM, Sowden RG, Ling Q, et al. Differentiation of chromoplasts and other plastids in plants. Plant Cell Rep. 2019; 38: 803-18

[17] Llorente B, Martinez-Garcia JF, Stange C, et al. Illuminating colors: regulation of carotenoid biosynthesis and accumulation by light. Curr Opin Plant Biol. 2017; 37: 49-55

[18] Cortleven A, Marg I, Yamburenko MV, et al. Cytokinin regulates the etioplast-chloroplast transition through the two-component signaling system and activation of chloroplast-related genes. Plant Physiol. 2016; 172: 464-78

[19] Shanmugabalaji V, Chahtane H, Accossato S, et al. Chloroplast biogenesis controlled by DELLA-TOC159 interaction in early plant development. Curr Biol. 2018; 28: 2616-23.e5

[20] Cackett L, Luginbuehl LH, Schreier TB, et al. Chloroplast development in green plant tissues: the interplay between light, hormone, and transcriptional regulation. New Phytol. 2022; 233: 2000-16

[21] Altamura MM, Piacentini D, Della F, et al. Plastid dynamism integrates development and environment. Plant Physiol Bioch. 2024; 213: 108813

[22] Solymosi K, Schoefs B . Etioplast and etio-chloroplast formation under natural conditions: the dark side of chlorophyll biosynthesis in angiosperms. Photosynth Res. 2010; 105: 143-66

[23] Tachibana R, Akema R, Yoshihara A, et al. Dark-inducible BGH2 suppresses GLK transcription factors and maintains plastid homeostasis to promote light adaptation. Plant Cell. 2025; 37: koaf180

[24] Armarego-Marriott T, Sandoval-Ibañez O, Kowalewska Ł . Beyond the darkness: recent lessons from etiolation and de-etiolation studies. J Exp Bot. 2020; 71: 1215-25

[25] Dhalsamant K, Singh CB, Lankapalli R . A review on greening and glycoalkaloids in potato tubers: potential solutions. J Agric Food Chem. 2022; 70: 13819-31

[26] Anstis PJP, Northcote DH . Development of chloroplasts from amyloplasts in potato tuber discs. New Phytol. 1973; 72: 449-63

[27] Zhu YS, Merkle-Lehman DL, Kung SD . Light-induced transformation of amyloplasts into chloroplasts in potato tubers. Plant Physiol. 1984; 75: 142-5

[28] Zhang H, Zhao Z, Song B, et al. Light-induced ultrastructure changes of amyloplasts and effect of nitrogen fertilization on greening in potato tubers (Solanum tuberosum L.) . Postharvest Biol Tec. 2020; 168: 111275

[29] Fuentes P, Pizarro L, Moreno JC, et al. Light-dependent changes in plastid differentiation influence carotenoid gene expression and accumulation in carrot roots. Plant Mol Biol. 2012; 79: 47-59

[30] Norén Lindbäck L, Ji Y, Cervela-Cardona L, et al. An interplay between bZIP16, bZIP68, and GBF1 regulates nuclear photosynthetic genes during photomorphogenesis in Arabidopsis. New Phytol. 2023; 240: 1082-96

[31] Han X, Zhang Y, Lou Z, et al. Time series single-cell transcriptional atlases reveal cell fate differentiation driven by light in Arabidopsis seedlings. Nat Plants. 2023; 9: 2095-109

[32] Yang EJ, Yoo CY, Liu J, et al. NCP activates chloroplast transcription by controlling phytochrome-dependent dual nuclear and plastidial switches. Nat Commun. 2019; 10: 2630

[33] Chang G, Xiang F, Fan Y, et al. Light signal transduction in plants: insights from phytochrome nuclear translocation and photobody formation. New Phytol. 2025; 248: 2221-35

[34] Li Y, Cao T, Guo Y, et al. Regulatory and retrograde signaling networks in the chlorophyll biosynthetic pathway. J Integr Plant Biol. 2025; 67: 887-911

[35] Li J, Li G, Wang H, et al. Phytochrome signaling mechanisms. Arabidopsis Book. 2011; 9: e0148

[36] Jarvis P, López-Juez E . Biogenesis and homeostasis of chloroplasts and other plastids. Nat Rev Mol Cell Biol. 2013; 14: 787-802

[37] Jiang X, Li H, Wang T, et al. Gibberellin indirectly promotes chloroplast biogenesis as a means to maintain the chloroplast population of expanded cells. Plant J. 2012; 72: 768-80

[38] Zhang D, Tan W, Yang F, et al. A BIN2-GLK1 signaling module integrates brassinosteroid and light signaling to repress chloroplast development in the dark. Dev Cell. 2021; 56: 310-24.e7

[39] Tachibana R, Abe S, Marugami M, et al. BPG4 regulates chloroplast development and homeostasis by suppressing GLK transcription factors and involving light and brassinosteroid signaling. Nat Commun. 2024; 15: 370

[40] Kobayashi K, Baba S, Obayashi T, et al. Regulation of root greening by light and auxin/cytokinin signaling in Arabidopsis. Plant Cell. 2012; 24: 1081-95

[41] Zhang T, Zhang R, Zeng X, et al. GLK transcription factors accompany ELONGATED HYPOCOTYL5 to orchestrate light-induced seedling development in Arabidopsis. Plant Physiol. 2024; 194: 2400-21

[42] Chiang YH, Zubo YO, Tapken W, et al. Functional characterization of the GATA transcription factors GNC and CGA1 reveals their key role in chloroplast development, growth, and division in Arabidopsis. Plant Physiol. 2012; 160: 332-48

[43] Kowalewska Ł, Mazur R, Suski S, et al. Three-dimensional visualization of the tubular-lamellar transformation of the internal plastid membrane network during runner bean chloroplast biogenesis. Plant Cell. 2016; 28: 875-91

[44] Liang Z, Yeung WT, Ma J, et al. Electron tomography of prolamellar bodies and their transformation into grana thylakoids in cryofixed Arabidopsis cotyledons. Plant Cell. 2022; 34: 3830-43

[45] Lebedev N, Van Cleve B, Armstrong G, et al. Chlorophyll synthesis in a deetiolated (det340) mutant of Arabidopsis without NADPH-protochlorophyllide (PChlide) oxidoreductase (POR) A and photoactive PChlide-F655 . Plant Cell. 1995; 7: 2081-90

[46] Sakuraba Y, Rahman ML, Cho SH, et al. The rice faded green leaf locus encodes protochlorophyllide oxidoreductase B and is essential for chlorophyll synthesis under high light conditions. Plant J. 2013; 74: 122-33

[47] Marano MR, Serra EC, Orellano EG, et al. The path of chromoplast development in fruits and flowers. Plant Sci. 1993; 94: 1-17

[48] Vainstein A, Sharon R . Biogenesis of petunia and carnation corolla chloroplasts: changes in the abundance of nuclear and plastid-encoded photosynthesis-specific gene products during flower development. Physiol Plant. 1993; 89: 192-8

[49] Weston E, PYKE KA . Developmental ultrastructure of cells and plastids in the petals of wallflower (Erysimum cheiri) . Ann Bot-london. 1999; 84: 763-9

[50] Takahashi S, Ozawa S, Sonoike K, et al. Morphological and cytological observations of corolla green spots reveal the presence of functional chloroplasts in Japanese gentian. PLoS One. 2020; 15: e0237173

[51] He J, Woon WL . Source-to-sink relationship between green leaves and green petals of different ages of the CAM orchid Dendrobium cv. Burana Jade . Photosynt. 2008; 46: 91-7

[52] Fu H, Zeng T, Zhao Y, et al. Identification of chlorophyll metabolism-and photosynthesis-related genes regulating green flower color in Chrysanthemum by integrative transcriptome and weighted correlation network analyses. Genes. 2021; 12: 449

[53] Smith M, Butler RD . Ultrastructural aspects of petal development in Cucumis sativus with particular reference to the chromoplasts . Protoplasma. 1971; 73: 1-13

[54] Falk H. Chromoplasts of Tropaeolum majus L.: structure and development . Planta. 1976; 128: 15-22

[55] Juneau P, Le Lay P, Böddi B, et al. Relationship between the structural and functional changes of the photosynthetic apparatus during chloroplast-chromoplast transition in flower bud of Lilium longiflorum . Photochem Photobiol. 2002; 75: 377

[56] Pyke KA, Page AM . Plastid ontogeny during petal development in Arabidopsis. Plant Physiol. 1998; 116: 797-803

[57] He YK, Zhu C, Wang D, et al. Cloning of plastid division gene GlFtsZ from Gentiana lutea and its expression during petal development . Prog Nat Sci. 2002; 12: 597-97

[58] Beale SI . Green genes gleaned. Trends Plant Sci. 2005; 10: 309-12

[59] Wang P, Grimm B . Connecting chlorophyll metabolism with accumulation of the photosynthetic apparatus. Trends Plant Sci. 2021; 26: 484-95

[60] Sirijovski N, Lundqvist J, Rosenbäck M, et al. Substrate-binding model of the chlorophyll biosynthetic magnesium chelatase BchH subunit. J Biol Chem. 2008; 283: 11652-60

[61] Reid JD, Hunter CN . Current understanding of the function of magnesium chelatase. Biochem Soc Trans. 2002; 30: 643-5

[62] Nguyen HC, Melo AA, Kruk J, et al. Photocatalytic LPOR forms helical lattices that shape membranes for chlorophyll synthesis. Nat Plants. 2021; 7: 437-44

[63] Tanaka R, Tanaka A . Tetrapyrrole biosynthesis in higher plants. Annu Rev Plant Biol. 2007; 58: 321-46

[64] Mochizuki N, Tanaka R, Grimm B, et al. The cell biology of tetrapyrroles: a life and death struggle. Trends Plant Sci. 2010; 15: 488-98

[65] Tanaka R, Tanaka A . Chlorophyll cycle regulates the construction and destruction of the light-harvesting complexes. Biochim Biophys Acta. 2011; 1807: 968-76

[66] Hörtensteiner S . Chlorophyll degradation during senescence. Annu Rev Plant Biol. 2006; 57: 55-77

[67] Schelbert S, Aubry S, Burla B, et al. Pheophytin pheophorbide hydrolase (pheophytinase) is involved in chlorophyll breakdown during leaf senescence in Arabidopsis. Plant Cell. 2009; 21: 767-85

[68] Chen J, Ren G, Kuai B . The mystery of Mendel’s stay-green: magnesium stays chelated in chlorophylls. Mol Plant. 2016; 9: 1556-8

[69] Shimoda Y, Ito H, Tanaka A . Arabidopsis STAY-GREEN, Mendel’s green cotyledon gene, encodes magnesium-dechelatase . Plant Cell. 2016; 28: 2147-60

[70] Park S, Yu J, Park J, et al. The senescence-induced stay-green protein regulates chlorophyll degradation. Plant Cell. 2007; 19: 1649-64

[71] Sato Y, Morita R, Nishimura M, et al. Mendel’s green cotyledon gene encodes a positive regulator of the chlorophyll-degrading pathway. Proc Natl Acad Sci USA. 2007; 104: 14169-74

[72] Meguro M, Ito H, Takabayashi A, et al. Identification of the 7-hydroxymethyl chlorophyll a reductase of the chlorophyll cycle in Arabidopsis. Plant Cell. 2011; 23: 3442-53

[73] Kusaba M, Ito H, Morita R, et al. Rice NON-YELLOW COLORING1 is involved in light-harvesting complex II and grana degradation during leaf senescence. Plant Cell. 2007; 19: 1362-75

[74] Hörtensteiner S, Kräutler B . Chlorophyll breakdown in higher plants. Biochim Biophys Acta. 2011; 1807: 977-88

[75] Wang L, Albert NW, Zhang H, et al. Temporal and spatial regulation of anthocyanin biosynthesis provide diverse flower colour intensities and patterning in Cymbidium orchid . Planta. 2014; 240: 983-1002

[76] Morimoto H, Ando Y, Sugihara H, et al. Information on flower coloration and pigmentation in current carnation cultivars for use in future flower-color breeding. Hort J. 2021; 90: 428-49

[77] Osterc G, Ravnjak B, Hudina M, et al. Genotype diversity assessment of common snowdrop (Galanthus nivalis L.) based on chlorophyll and carotenoids partitioning among different plant organs . Eur J Hortic Sci. 2021; 86: 252-9

[78] Ohmiya A, Hirashima M, Yagi M, et al. Identification of genes associated with chlorophyll accumulation in flower petals. PLoS One. 2014; 9: e113738

[79] Ke Y, Ashraf U, Wang D, et al. Function of anthocyanin and chlorophyll metabolic pathways in the floral sepals color formation in different hydrangea cultivars. Plants. 2025; 14: 742

[80] Xu L, Yang P, Feng Y, et al. Spatiotemporal transcriptome analysis provides insights into bicolor tepal development in Lilium “Tiny Padhye” . Front Plant Sci. 2017; 8: 398

[81] Zhu M, Meng X, Chen G, et al. Physiological, biochemical, and molecular differences in chloroplast synthesis between leaf and corolla of cabbage (Brassica rapa L. var. chinensis) and rapeseed (Brassica napus L.) . Plant Growth Regul. 2017; 82: 91-101

[82] Hao Z, Liu S, Hu L, et al. Transcriptome analysis and metabolic profiling reveal the key role of carotenoids in the petal coloration of Liriodendron tulipifera . Hortic Res. 2020; 7: 70

[83] Iijima L, Kishimoto S, Ohmiya A, et al. Esterified carotenoids are synthesized in petals of carnation (Dianthus caryophyllus) and accumulate in differentiated chromoplasts . Sci Rep. 2020; 10: 15256

[84] Yong S, Chen Q, Xu F, et al. Exploring the interplay between angiosperm chlorophyll metabolism and environmental factors. Planta. 2024; 260: 25

[85] Sineshchekov VA, Belyaeva OB . Regulation of chlorophyll biogenesis by phytochrome A. Biochemistry. 2019; 84: 491-508

[86] Kuai B, Chen J, Hörtensteiner S . The biochemistry and molecular biology of chlorophyll breakdown. J Exp Bot. 2018; 69: 751-67

[87] Ni M, Tepperman JM, Quail PH . PIF3, a phytochrome-interacting factor necessary for normal photoinduced signal transduction, is a novel basic helix-loop-helix protein. Cell. 1998; 95: 657-67

[88] Khanna R, Huq E, Kikis EA, et al. A novel molecular recognition motif necessary for targeting photoactivated phytochrome signaling to specific basic helix-loop-helix transcription factors. Plant Cell. 2004; 16: 3033-44

[89] Leivar P, Quail PH . PIFs: pivotal components in a cellular signaling hub. Trends Plant Sci. 2011; 16: 19-28

[90] Han X, Huang X, Deng XW . The photomorphogenic central repressor COP1: conservation and functional diversification during evolution. Plant Commun. 2020; 1: 100044

[91] Song Y, Yang C, Gao S, et al. Age-triggered and dark-induced leaf senescence require the bHLH transcription factors PIF3, 4, and 5. Mol Plant. 2014; 7: 1776-87

[92] Huq E, Al-Sady B, Hudson M, et al. Phytochrome-interacting factor 1 is a critical bHLH regulator of chlorophyll biosynthesis. Science. 2004; 305: 1937-41

[93] Shin J, Kim K, Kang H, et al. Phytochromes promote seedling light responses by inhibiting four negatively-acting phytochrome-interacting factors. Proc Natl Acad Sci USA. 2009; 106: 7660-5

[94] Saijo Y, Zhu D, Li J, et al. Arabidopsis COP1/SPA1 complex and FHY1/FHY3 associate with distinct phosphorylated forms of phytochrome A in balancing light signaling. Mol Cell. 2008; 31: 607-13

[95] Li Y, Lin R . Advances in the regulation mechanism of chlorophyll synthesis. Chin Bull Life Sci. 2024; 36: 1141-8

[96] Zhong S, Zhao M, Shi T, et al. EIN3/EIL1 cooperate with PIF1 to prevent photo-oxidation and to promote greening of Arabidopsis seedlings. Proc Natl Acad Sci USA. 2009; 106: 21431-6

[97] Cheminant S, Wild M, Bouvier F, et al. DELLAs regulate chlorophyll and carotenoid biosynthesis to prevent photooxidative damage during seedling deetiolation in Arabidopsis. Plant Cell. 2011; 23: 1849-60

[98] Liu L, Lin N, Liu X, et al. From chloroplast biogenesis to chlorophyll accumulation: the interplay of light and hormones on gene expression in Camellia sinensis cv. Shuchazao leaves . Front Plant Sci. 2020; 11: 256

[99] Yuan Y, Xu X, Gong Z, et al. Auxin response factor 6A regulates photosynthesis, sugar accumulation, and fruit development in tomato. Hortic Res. 2019; 6: 85

[100] Dong XM, Zhang W, Tu M, et al. Spatial and temporal regulation of flower coloration in Cymbidium lowianum . Plant Cell Environ. 2025; 48: 3844-60

[101] Fang J, Liu S, Chen S, et al. A R1-type MYB CmREVEILLE2 regulates light-mediated chlorophyll biosynthesis and green color formation in chrysanthemum flowers. Hortic Adv. 2025; 3: 17

[102] Luo J, Wang H, Chen S, et al. CmNAC73 mediates the formation of green color in chrysanthemum flowers by directly activating the expression of chlorophyll biosynthesis genes HEMA1 and CRD1 . Genes. 2021; 12: 704

[103] Chen S, Wang H, Li R, et al. Characterization of CmMYC2 in formation of green color in ray florets of chrysanthemum. Acta Hortic Sin. 2022; 49: 2377-87

[104] Jang H, Song S . Ectopic expression of AtMYB115 and AtMYB118 induces green tissue formation in non-green organs of Arabidopsis thaliana . Genes Genom. 2025; 47: 587-97

[105] Yuan S, Piao C-L, Zhang X, et al. Overexpression of SEPALLATA3-like gene SnMADS37 generates green petal-tip flowers in Solanum nigrum . Plants. 2025; 14: 1891

[106] Liu D, Zhang L, Hu A, et al. The MYB transcription factor ClPC modulates petal color and chlorophyll accumulation in watermelon. Plant Sci. 2025; 359: 112586

[107] Ohmiya A, Oda-Yamamizo C, Kishimoto S . Overexpression of CONSTANS-like 16 enhances chlorophyll accumulation in petunia corollas . Plant Sci. 2019; 280: 90-6

[108] Zhang B, Feng M, Zhang J, et al. Involvement of CONSTANS-like proteins in plant flowering and abiotic stress response. Int J Mol Sci. 2023; 24: 16585

[109] Qu H, Liang S, Hu L, et al. Overexpression of Liriodendron hybrid LhGLK1 in Arabidopsis leads to excessive chlorophyll synthesis and improved growth . Int J Mol Sci. 2024; 25: 6968

[110] Jack T, Fox GL, Meyerowitz EM . Arabidopsis homeotic gene APETALA3 ectopic expression: transcriptional and posttranscriptional regulation determine floral organ identity . Cell. 1994; 76: 703-16

[111] Zhou L, Iqbal A, Yang M, et al. Research progress on gene regulation of plant floral organogenesis. Genes. 2025; 16: 79

[112] Vandenbussche M, Zethof J, Royaert S, et al. The duplicated B-class heterodimer model: whorl-specific effects and complex genetic interactions in Petunia hybrida flower development . Plant Cell. 2004; 16: 741-54

[113] Chopy M, Cavallini-Speisser Q, Chambrier P, et al. Cell layer-specific expression of the homeotic MADS-box transcription factor PhDEF contributes to modular petal morphogenesis in petunia. Plant Cell. 2024; 36: 324-45

[114] Guo X, Hu Z, Yin W, et al. The tomato floral homeotic protein FBP1-like gene, SlGLO1, plays key roles in petal and stamen development . Sci Rep. 2016; 6: 20454

[115] Van Der Krol AR, Brunelle A, Tsuchimoto S, et al. Functional analysis of petunia floral homeotic MADS box gene pMADS1 . Genes Dev. 1993; 7: 1214-28

[116] Lange M, Orashakova S, Lange S, et al. The seirena B class floral homeotic mutant of California poppy (Eschscholzia californica) reveals a function of the enigmatic PI motif in the formation of specific multimeric MADS domain protein complexes . Plant Cell. 2013; 25: 438-53

[117] Zhang R, Guo C, Zhang W, et al. Disruption of the petal identity gene APETALA3-3 is highly correlated with loss of petals within the buttercup family (Ranunculaceae) . Proc Natl Acad Sci USA. 2013; 110: 5074-9

[118] Mara CD, Irish VF . Two GATA transcription factors are downstream effectors of floral homeotic gene action in Arabidopsis. Plant Physiol. 2008; 147: 707-18

[119] Mara CD, Huang T, Irish VF . The Arabidopsis floral homeotic proteins APETALA3 and PISTILLATA negatively regulate the BANQUO genes implicated in light signaling . Plant Cell. 2010; 22: 690-702

[120] Ditta G, Pinyopich A, Robles P, et al. The SEP4 gene of Arabidopsis thaliana functions in floral organ and meristem identity . Curr Biol. 2004; 14: 1935-40

[121] Yu X, Chen G, Guo X, et al. Silencing SlAGL6, a tomato AGAMOUS-LIKE6 lineage gene, generates fused sepal and green petal . Plant Cell Rep. 2017; 36: 959-69

[122] Matsubara K, Shimamura K, Kodama H, et al. Green corolla segments in a wild petunia species caused by a mutation in FBP2, a SEPALLATA-like MADS box gene . Planta. 2008; 228: 401-9

[123] Fan Y, Yue D, Liang Z, et al. Genome-wide identification of expansin gene family and its association with sepal expansion during flower opening in Hydrangea macrophylla . J Plant Growth Regul. 2025; 44: 5129-46

[124] Sakai H, Medrano LJ, Meyerowitz EM . Role of SUPERMAN in maintaining Arabidopsis floral whorl boundaries . Nature. 1995; 378: 199-203

[125] Liu Q, Xu K, Ma N, et al. Overexpression of a novel chrysanthemum SUPERMAN-like gene in tobacco affects lateral bud outgrowth and flower organ development . Plant Physiol Biochem. 2014; 77: 1-6

[126] Shin MR, Seo SG, Kim JS, et al. Alteration of floral organ identity by over-expression of IbMADS3-1 in tobacco . Transgenic Res. 2011; 20: 365-76

[127] Lee J, Lee I . Regulation and function of SOC1, a flowering pathway integrator. J Exp Bot. 2010; 61: 2247-54

[128] Ruokolainen S, Ng YP, Albert VA, et al. Over-expression of the Gerbera hybrida At-SOC1-like1 gene Gh-SOC1 leads to floral organ identity deterioration . Ann Bot. 2011; 107: 1491-9

[129] Wang Z, Shen Y, Yang X, et al. Overexpression of particular MADS-box transcription factors in heat-stressed plants induces chloroplast biogenesis in petals. Plant Cell Environ. 2019; 42: 1545-60

[130] Ning G, Yan X, Chen H, et al. Genetic manipulation of SOC1-like genes promotes photosynthesis in flowers and leaves and enhances plant tolerance to high temperature . Plant Biotechnol J. 2021; 19: 8-10

[131] He D, Yu S, Qu L, et al. Methyl jasmonate enhances vase life and alters physiological and molecular responses in tree peony ’Luoyang Hong’ cut flowers. Postharvest Biol Tec. 2025; 224: 113481

[132] Mizuno T, Fukuta N, Shimizu-Yumoto H . Nonuniform coloration of harvested flower buds of double-flowered eustoma is reduced by methyl jasmonate treatment . Hort J. 2017; 86: 244-51

[133] Nabipour Sanjbod R, Chamani E, Pourbeyrami HY, et al. Autophagic and phytochemical aspects of color changes in white petals of snapdragon flower during development and senescence. Physiol Mol Biol Plants. 2023; 29: 695-707

[134] Mizuno T, Sugahara K, Tsutsumi C, et al. Identification of anthocyanin and other flavonoids from the green-blue petals of Puya alpestris (Bromeliaceae) and a clarification of their coloration mechanism . Phytochemistry. 2021; 181: 112581

[135] Dyer A, Lunau K . It’s not easy being green. A commentary on ‘green flowers need yellow to get noticed in a green world’. < i> Ann Bot i>. 2025; 135: i-iv, mcaf016

[136] Del Valle JC, León-Osper M, Domínguez-González C, et al. Green flowers need yellow to get noticed in a green world. Ann Bot. 2025; 135: 1281-92, mcae213

[137] Gao S, Gao J, Zhu X, et al. ABF2, ABF3, and ABF4 promote ABA-mediated chlorophyll degradation and leaf senescence by transcriptional activation of chlorophyll catabolic genes and senescence-associated genes in Arabidopsis. Mol Plant. 2016; 9: 1272-85

[138] Qiu K, Li Z, Yang Z, et al. EIN3 and ORE1 accelerate degreening during ethylene-mediated leaf senescence by directly activating chlorophyll catabolic genes in Arabidopsis. PLoS Genet. 2015; 11: e1005399

[139] Zhu X, Chen J, Xie Z, et al. Jasmonic acid promotes degreening via MYC2/3/4- and ANAC019/055/072-mediated regulation of major chlorophyll catabolic genes. Plant J. 2015; 84: 597-610

[140] Ohmiya A, Kishimoto S, Aida R, et al. Carotenoid cleavage dioxygenase (CmCCD4a) contributes to white color formation in chrysanthemum petals. Plant Physiol. 2006; 142: 1193-201

[141] Jeknić Z, Jeknić S, Jevremović S, et al. Alteration of flower color in Iris germanica L. ‘Fire Bride’ through ectopic expression of phytoene synthase gene (crtB) from Pantoea agglomerans . Plant Cell Rep. 2014; 33: 1307-21

[142] Ohmiya A . Molecular mechanisms underlying the diverse array of petal colors in chrysanthemum flowers. Breed Sci. 2018; 68: 119-27