FveDAD2 negatively regulates branch crowns by affecting abscisic acid metabolism through FveHB7 in woodland strawberry

Abstract

The branch crown is an important trait of the strawberry that influences plant architecture and yield. Strigolactones (SLs) are significant hormones involved in the plant growth response and are crucial for regulating branching. Previous studies have shown that SL signaling regulates branching by affecting abscisic acid (ABA) biosynthesis. In this study, we observed that the SL signaling pathway can affect branching by regulating ABA catabolism in strawberry. FveDAD2 in woodland strawberry was identified as the receptor for SL. Three FveDAD2-RNAi transgenic lines exhibited the phenotype of multibranched crowns and smaller fruits. Like the alpha/beta hydrolase DWARF14 (D14), the interaction of FveDAD2 with FveSMXL7 depended on SL. The FveSMXL7-RNAi transgenic plants exhibited a less branched phenotype compared to the control plant. In addition, FveSMXL7 binds to the promoter of FveHB7 and represses its transcription. FveHB7, a homeobox transcription factor, negatively regulates the transcription of the ABA 8′-hydroxylase gene (FveABA8'OH1). The expression of FveHB7 was up-regulated, while the expression of the FveABA8'OH1 was down-regulated in FveSMXL7-RNAi. ABA levels were reduced in the shoot tips of the FveDAD2-RNAi lines and increased in the FveSMXL7-RNAi lines. Treating wild-type plants with 20 μM ABA significantly suppressed the number of branch crowns, while 40 μM ABA rescued the phenotype of FveDAD2-RNAi. In conclusion, our research indicates that SL signaling may regulate branching by affecting ABA catabolism. These findings provide a theoretical basis for elucidating the mechanism of the development of branch crowns in the strawberry.

Acknowledgements

We want to express our gratitude to Prof. Nan Ma (China Agricultural University) for providing the nuclear marker NF-YA4-mCherry and to Prof. Yuepeng Han (Wuhan Botanical Garden, Chinese Academy of Sciences) for providing pGreenII0800-LUC. This work was supported by the National Natural Science Foundation of China (Grant No. 32130092) and the project of Liaoning Province Germplasm Innovation Grain Storage and Technology Special Program (2023020525-JH1/102-04).

Authors contributions

Z.Z., H.S., and J.Z. conceived and designed the experiments. H.S. and W.L. performed the experiments. H.S. and Y.W. analyzed the data and wrote the manuscript. All the authors revised and approved the final version.

Data availability

All relevant data can be found within the manuscript and its supporting materials.

Conflicts of interest statement

The authors declare that there are no conflicts of interest.

Supplementary material

Supplementary material is available at Horticulture Research online.

References

[1] Han Y, Qu M, Liu Z. et al. Transcription factor FveMYB117a inhibits axillary bud outgrowth by regulating cytokinin home-ostasis in woodland strawberry. Plant Cell. 2024; 36:2427-46

[2] Kelly JH, Tucker MR, Brewer PB. The strigolactone pathway is a target for modifying crop shoot architecture and yield. Biology. 2023; 12:95

[3] Gomez-Roldan V, Fermas S, Brewer PB. et al. Strigolactone inhibition of shoot branching. Nature. 2008; 455:189-94

[4] Hamiaux C, Drummond RS, Janssen BJ. et al. DAD2 is an alpha/beta hydrolase likely to be involved in the percep-tion of the plant branching hormone, strigolactone. Curr Biol. 2012; 22:2032-6

[5] Yao R, Wang L, Li Y. et al. Rice DWARF14 acts as an uncon-ventional hormone receptor for strigolactone. J Exp Bot. 2018; 69:2355-65

[6] Zhou F, Lin Q, Zhu L. et al. D14-SCFD3-dependent degra-dation of D53 regulates strigolactone signalling. Nature. 2013; 504:406-10

[7] Liang Y, Ward S, Li P. et al. SMAX1-LIKE7 signals from the nucleus to regulate shoot development in Arabidopsis via partially EAR motif-independent mechanisms. Plant Cell. 2016; 28:1581-601

[8] Kerr SC, Patil SB, de Saint GA. et al. Integration of the SMXL/D53 strigolactone signalling repressors in the model of shoot branching regulation in Pisum sativum. Plant J. 2021; 107:1756-70

[9] Liu J, Cheng X, Liu P. et al. miR156-targeted SBP-box tran-scription factors interact with DWARF53 to regulate TEOSINTE BRANCHED1 and BARREN STALK1 expression in bread wheat. Plant Physiol. 2017; 174:1931-48

[10] Song X, Lu Z, Yu H. et al. IPA1 functions as a downstream tran-scription factor repressed by D53 in strigolactone signaling in rice. Cell Res. 2017; 27:1128-41

[11] Sun H, Guo X, Qi X. et al. SPL14/17 act downstreamof strigolac-tone signalling to modulate rice root elongation in response to nitrate supply. Plant J. 2021; 106:649-60

[12] Wang L, Wang B, Yu H. et al. Transcriptional regulation of strigolactone signalling in Arabidopsis. Nature. 2020; 583: 277-81

[13] Soundappan I, Bennett T, Morffy N. et al. SMAX1-LIKE/D53 family members enable distinct MAX2-dependent responses to strigolactones and karrikins in Arabidopsis. Plant Cell. 2015; 27:3143-59

[14] Zhang J, Mazur E, Balla J. et al. Strigolactones inhibit auxin feedback on PIN-dependent auxin transport canalization. Nat Commun. 2020; 11:3508

[15] van Rongen M, Bennett T, Ticchiarelli F. et al. Connective auxin transport contributes to strigolactone-mediated shoot branching control independent of the transcription factor BRC1. PLoS Genet. 2019; 15:1008023

[16] Duan J, Yu H, Yuan K. et al. Strigolactone promotes cytokinin degradation through transcriptional activation of CYTOKININ OXIDASE/DEHYDROGENASE 9 in rice. Proc Natl Acad Sci U S A. 2019; 116:14319-24

[17] Cao D, Chabikwa T, Barbier F. et al. Auxin-independent effects of apical dominance induce changes in phytohormones correlated with bud outgrowth. Plant Physiol. 2023; 192: 1420-34

[18] Sun H, Guo X, Zhu X. et al. Strigolactone and gibberellin signal-ing coordinately regulate metabolic adaptations to changes in nitrogen availability in rice. Mol Plant. 2023; 16:588-98

[19] Aguilar-Martínez JA, Poza-Carrión CS, Cubas P. Arabidopsis BRANCHED1 acts as an integrator of branching signals within axillary buds. Plant Cell. 2007; 19:458-72

[20] Braun N, de Saint Germain A, Pillot J-P. et al. The pea TCP tran-scription factor PsBRC1 Acts downstream of strigolactones to control shoot branching. Plant Physiol. 2012; 158:225-38

[21] González-Grandío E, Pajoro A, Franco-Zorrilla JM. et al. Abscisic acid signaling is controlled by a BRANCHED1/HD-ZIP I cascade in Arabidopsis axillary buds. Proc Natl Acad Sci U S A. 2016; 114:245-54

[22] Dong Z, Xiao Y, Govindarajulu R. et al. The regulatory land-scape of a core maize domestication module controlling bud dormancy and growth repression. Nat Commun. 2019; 10:3810

[23] Wu K, Wang S, Song W. et al. Enhanced sustainable green rev-olution yield via nitrogen-responsive chromatin modulation in rice. Science. 2020;367:eaaz2046

[24] Hu Q, Liu H, He Y. et al. Regulatory mechanisms of strigolac-tone perception in rice. Cell. 2024; 187:7551-7567.e17

[25] Barbier FF, Cao D, Fichtner F. et al. HEXOKINASE1 signalling promotes shoot branching and interacts with cytokinin and strigolactone pathways. New Phytol. 2021; 231:1088-104

[26] Salam BB, Barbier F, Danieli R. et al. Sucrose promotes stem branching through cytokinin. Plant Physiol. 2021; 185:1708-21

[27] Patil SB, Barbier FF, Zhao J. et al. Sucrose promotes D53 accu-mulation and tillering in rice. New Phytol. 2021; 234:122-36

[28] Wang F, Han T, Song Q. et al. The Rice circadian clock regulates tiller growth and panicle development through strigolactone signaling and sugar sensing. Plant Cell. 2020; 32:3124-38

[29] Xie Y, Liu Y, Ma M. et al. Arabidopsis FHY3 and FAR1 integrate light and strigolactone signaling to regulate branching. Nat Commun. 2020; 11:1955

[30] Andres J, Caruana J, Liang J. et al. Woodland strawberry axil-lary bud fate is dictated by a crosstalk of environmental and endogenous factors. Physiol Plant. 2021; 187:1221-34

[31] Fan G, Andres J, Olbricht K. et al. Natural variation in the control of flowering and shoot architecture in diploid Fragaria species. Front Plant Sci. 2022; 13:832795

[32] Peng Y, Jiang Y, He C. et al. Exogenous GR24 inhibits straw-berry tillering by affecting the phytohormone signaling and sugar metabolism pathways. Agronomy. 2023; 13:3078

[33] Vegh A, Incze N, Fabian A. et al. Comprehensive analysis of DWARF14-LIKE 2 (DLK2) reveals its functional divergence from strigolactone-related paralogs. Front Plant Sci. 2017; 8: 1641

[34] Waters MT, Nelson DC, Scaffidi A. et al. Specialisation within the DWARF14 protein family confers distinct responses to karrikins and strigolactones in Arabidopsis. Development. 2012; 139:1285-95

[35] Hu A, Zhao Q, Chen L. et al. Identification of conserved and divergent strigolactone receptors in sugarcane reveals a key residue crucial for plant branching control. Front Plant Sci. 2021; 12:747160

[36] Li W, Nguyen KH, Chu HD. et al. Comparative functional analyses of DWARF14 and KARRIKIN INSENSITIVE 2 in drought adaptation of Arabidopsis thaliana. Plant J. 2020; 103: 111-27

[37] Conn CE, Nelson DC. Evidence that KARRIKIN-INSENSITIVE2 (KAI2) receptors may perceive an unknown signal that is not Karrikin or Strigolactone. Front Plant Sci. 2016; 6:1219

[38] Khosla A, Morffy N, Li Q. et al. Structure-function analysis of SMAX1 reveals domains that mediate its karrikin-induced proteolysis and interaction with the receptor KAI2. Plant Cell. 2020; 32:2639-59

[39] Jiang L, Liu X, Xiong G. et al. DWARF 53 acts as a repressor of strigolactone signalling in rice. Nature. 2013; 504:401-5

[40] Hu Q, He Y, Wang L. et al. DWARF14, a receptor covalently linked with the active form of strigolactones, undergoes strigolactone-dependent degradation in Rice. Front Plant Sci. 2017; 8:1935

[41] Valdes AE, Overnas E, Johansson H. et al. The homeodomain-leucine zipper (HD-Zip) class I transcription factors ATHB7 and ATHB12 modulate abscisic acid signalling by regulating protein phosphatase 2C and abscisic acid receptor gene activ-ities. Plant Mol Biol. 2012; 80:405-18

[42] Ré DA, Dezar CA, Chan RL. et al. Nicotiana attenuata NaHD20 plays a role in leaf ABA accumulation during water stress, ben-zylacetone emission from flowers, and the timing of bolting and flower transitions. J Exp Bot. 2010; 62:155-66

[43] Son O, Hur YS, Kim YK. et al. ATHB12, an ABA-inducible homeodomain-leucine zipper (HD-Zip) protein of Arabidopsis, negatively regulates the growth of the inflorescence stem by decreasing the expression of a gibberellin 20-oxidase gene. Plant Cell Physiol. 2010; 51:1537-47

[44] Zhao S, Wang H, Jia X. et al. The HD-Zip I transcription factor MdHB7-like confers tolerance to salinity in transgenic apple (Malus domestica). Physiol Plant. 2021; 172:1452-64

[45] Kim HM, Park SH, Ma SH. et al. Promoted ABA hydroxy-lation by Capsicum annuum CYP707As overexpression sup-presses pollen maturation in Nicotiana tabacum. Front Plant Sci. 2020; 11:583767

[46] Li Q, Chen P, Dai S. et al. PacCYP707A2 negatively regulates cherry fruit ripening while PacCYP707A1 mediates drought tolerance. J Exp Bot. 2015; 66:3765-74

[47] Wang X, Jin B, Yan W. et al. Cucumber abscisic acid 8’-hydroxylase Csyf2 regulates yellow flesh by modulating carotenoid biosynthesis. Plant Physiol. 2023; 193:1001-15

[48] Hu J, Ji Y, Hu X. et al. BES1 functions as the co-regulator of D53-like SMXLs to inhibit BRC1 expression in strigolactone-regulated shoot branching in Arabidopsis. Plant Commun. 2020; 1:100014

[49] Zhang Y, Zhang Y, Sun Q. et al. Citrus transcription factor CsHB5 regulates abscisic acid biosynthetic genes and pro-motes senescence. Plant J. 2021; 108:151-68

[50] Dong S, Tarkowska D, Sedaghatmehr M. et al. The HB40-JUB1 transcriptional regulatory network controls gibberellin home-ostasis in Arabidopsis. Mol Plant. 2022; 15:322-39

[51] Zhao H, Wang Y, Zhao S. et al. HOMEOBOX PROTEIN 24 mediates the conversion of indole-3-butyric acid to indole-3-acetic acid to promote root hair elongation. New Phytol. 2021; 232:2057-70

[52] Liu X, Cheng L, Li R. et al. The HD-Zip transcription fac-tor SlHB15A regulates abscission by modulating jasmonoyl-isoleucine biosynthesis. Plant Physiol. 2022; 189:2396-412

[53] Clepet C, Devani RS, Boumlik R. et al. The miR166-SlHB15A regulatory module controls ovule development and parthenocarpic fruit set under adverse temperatures in tomato. Mol Plant. 2021; 14:1185-98

[54] Luo L, Takahashi M, Kameoka H. et al. Developmental analysis of the early steps in strigolactone-mediated axillary bud dor-mancy in rice. Plant J. 2019; 97:1006-21

[55] Liu X, Hu Q, Yan J. et al. ζ -Carotene isomerase suppresses tillering in Rice through the coordinated biosynthesis of strigolactone and abscisic acid. Mol Plant. 2020; 13:1784-801

[56] Chen J, Liu L, Wang G. et al. The AGAMOUS-LIKE 16-GENERAL REGULATORY FACTOR 1 module regulates axillary bud out-growth via catabolism of abscisic acid in cucumber. Plant Cell. 2024; 36:2689-708

[57] Sharma P, Jha AB, Dubey RS. Strigolactones: coordination with other phytohormones and enhancement of abiotic stress responses. Environ Exp Bot. 2024; 223:105782

[58] Gong Z, Xiong L, Shi H. et al. Plant abiotic stress response and nutrient use efficiency. Sci China Life Sci. 2020; 63:635-74

[59] Ali A, Shah T, Haider G. et al. Strigolactone-mediated oxida-tive stress alleviation in Brassica rapa through upregulating antioxidant system under water deficit conditions. J Plant Growth Regul. 2023; 42:4675-87

[60] Sedaghat M, Emam Y, Mokhtassi-Bidgoli A. et al. The potential of the synthetic strigolactone analogue GR24 for the main-tenance of photosynthesis and yield in winter wheat under drought: investigations on the mechanisms of action and delivery modes. Plants. 2021; 10:1223

[61] Zhang Y, Lv S, Wang G. Strigolactones are common regulators in induction of stomatal closure in planta. Plant Signal Behav. 2018; 13:e1444322

[62] Zhang X, Du BY, Turupu M. et al. Strigolactones enhance apple drought resistance via the MsABI5-MsSMXL1-MsNAC 022 cas-cade. Hortic Res. 2025;12:uhaf101

[63] Li W, Nguyen KH, Tran CD. et al. Negative roles of strigolactone-related SMXL6, 7 and 8 proteins in drought resistance in Arabidopsis. Biomolecules. 2020; 10:607

[64] Ré DA, Capella M, Bonaventure G. et al. Arabidopsis AtHB7 and AtHB12 evolved divergently to fine tune processes associated with growth and responses to water stress. BMC Plant Biol. 2014; 14:150

[65] Zhang X, Cheng Z, Fan G. et al. Transcription factor McHB7 improves ice plant drought tolerance through ABA signaling pathway. Int J Mol Sci. 2024; 25:4569

[66] Wu H, Li H, Chen H. et al. Identification and expression analysis of strigolactone biosynthetic and signaling genes reveal strigolactones are involved in fruit development of the woodland strawberry (Fragaria vesca). BMC Plant Biol. 2019; 19:1-19

[67] Katyayini NU, Rinne PLH, van der Schoot C. Strigolactone-based node-to-bud signaling may restrain shoot branching in hybrid aspen. Plant Cell Physiol. 2019; 60:2797-811

[68] Mashiguchi K, Sasaki E, Shimada Y. et al. Feedback-regulation of strigolactone biosynthetic genes and strigolactone-regulated genes in Arabidopsis. Biosci Biotechnol Biochem. 2014; 73:2460-5

[69] Liao X, Li M, Liu B. et al. Interlinked regulatory loops of ABA catabolism and biosynthesis coordinate fruit growth and ripening in woodland strawberry. Proc Natl Acad Sci USA. 2018;115:E11542-50

[70] Li W, Zhang J, Sun H. et al. FveRGA1, encoding a DELLA pro-tein, negatively regulates runner production in Fragaria vesca. Planta. 2018; 247:941-51

[71] Zhang S, Feng M, Chen W. et al. In rose, transcription factor PTM balances growth and drought survival via PIP2; 1 aqua-porin. Nat Plants. 2019; 5:290-9

[72] Li T, Jiang Z, Zhang L. et al. Apple (Malus domestica) MdERF 2 negatively affects ethylene biosynthesis during fruit ripening by suppressing MdACS1 transcription. Plant J. 2016; 88:735-48