Overexpression of SlOFP20 affects floral organ and pollen development

Abstract

The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape. There are 31 OFP members in the tomato genome. However, their roles in tomato growth and reproductive development are largely unknown. Here, we cloned the OFP transcription factor SlOFP20. Tomato plants overexpressing SlOFP20 displayed several phenotypic defects, including an altered floral architecture and fruit shape and reduced male fertility. SlOFP20 overexpression altered the expression levels of some brassinosteroid (BR)-associated genes, implying that SlOFP20 may play a negative role in the BR response, similar to its ortholog OsOFP19 in rice. Moreover, the transcript accumulation of gibberellin (GA)-related genes was significantly affected in the transgenic lines. SlOFP20 may play an important role in the crosstalk between BR and GA. The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants. In addition, the tomato pollen-associated genes SlCRK1, SlPMEI, LePRK3, SlPRALF, and LAT52 were all suppressed in the transgenic lines. Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.

References

[1] Gimenez, E. et al. TOMATO AGAMOUS1 and ARLEQUIN/TOMATO AGAMOUSLIKE1 MADS-box genes have redundant and divergent functions required for tomato reproductive development. Plant Mol. Biol. 91, 513-531 (2016).

[2] Ferreira e Silva, G. F. et al. microRNA156-targeted SPL/SBP box transcription factors regulate tomato ovary and fruit development. Plant J. 78, 604-618 (2014).

[3] Huang, B. et al. Overexpression of the class D MADS-box gene Sl-AGL11 impacts fleshy tissue differentiation and structure in tomato fruits. J. Exp. Bot. 68, 4869-4884 (2017).

[4] Ku, H. M., Doganlar, S., Chen, K. Y. & Tanksley, S. D. The genetic basis of pearshaped tomato fruit. Theor. Appl. Genet. 99, 844-850 (1999).

[5] Liu, J., Van Eck, J., Cong, B. & Tanksley, S. D. A new class of regulatory genes underlying the cause of pear-shaped tomato fruit. Proc. Natl Acad. Sci. USA 99, 13302-13306 (2002).

[6] Hackbusch, J., Richter, K., Müller, J., Salamini, F. & Uhrig, J. F. A central role of Arabidopsis thaliana ovate family proteins in networking and subcellular localization of 3-aa loop extension homeodomain proteins. Proc. Natl Acad. Sci. USA 102, 4908-4912 (2005).

[7] Wang, S., Chang, Y., Guo, J. & Chen, J. G. Arabidopsis Ovate Family Protein 1 is a transcriptional repressor that suppresses cell elongation. Plant J. 50, 858-872 (2007).

[8] Wang, Y. K. et al. Ovate family protein 1 as a plant Ku70 interacting protein involving in DNA double-strand break repair. Plant Mol. Biol. 74, 453-466 (2010).

[9] Wang, S. et al. Arabidopsis Ovate family proteins, a novel transcriptional repressor family, control multiple aspects of plant growth and development. PloS ONE 6, https://doi.org/10.1371/journal.pone.0023896 (2011).

[10] Li, E., Wang, S., Liu, Y., Chen, J. G. & Douglas, C. J. OVATE FAMILY PROTEIN4 (OFP4) interaction with KNAT7 regulates secondary cell wall formation in Arabidopsis thaliana. Plant J. 67, 328-341 (2011).

[11] Zhang, L. et al. Ovate family protein1 interaction with BLH3 regulates transition timing from vegetative to reproductive phase in Arabidopsis. Biochem. Biophys. Res. Commun. 470, 492-497 (2016).

[12] Schmitz, A. J., Begcy, K., Sarath, G. & Walia, H. Rice Ovate Family Protein 2 (OFP2) alters hormonal homeostasis and vasculature development. Plant Sci. 241, 177-188 (2015).

[13] Yang, C., Shen, W., He, Y., Tian, Z. & Li, J. OVATE family protein 8 positively mediates brassinosteroid signaling through interacting with the GSK3-like kinase in rice. PLoS Genet. 12, https://doi.org/10.1371/journal.pgen.1006118 (2016).

[14] Xiao, Y., Liu, D., Zhang, G., Tong, H. & Chu, C. Brassinosteroids regulate OFP1, a DLT interacting protein, to modulate plant architecture and grain morphology in rice. Front. Plant Sci. 8, 1698 (2017).

[15] Yang, C., Ma, Y., He, Y., Tian, Z. & Li, J. OsOFP19 modulates plant architecture by integrating the cell division pattern and brassinosteroid signaling. Plant J. 93, 489-501 (2018).

[16] Liu, J. et al. Banana ovate family protein MaOFP1 and MADS-box protein MuMADS1 antagonistically regulated banana fruit ripening. PLoS ONE 10, e0123870 (2015).

[17] Liu, J. et al. MuMADS1 and MaOFP1 regulate fruit quality in a tomato ovate mutant. Plant Biotechnol. J. 16, 989-1001 (2018).

[18] Wang, S., Chang, Y. & Ellis, B. Overview of OVATE FAMILY PROTEINS, A novel class of plant-specific growth regulators. Front. Plant Sci. 7, 417 (2016).

[19] Pagnussat, G. C., Yu, H. J. & Sundaresan, V. Cell-fate switch of synergid to egg cell in Arabidopsis eostre mutant embryo sacs arises from misexpression of the BEL1-like homeodomain gene BLH1. Plant Cell 19, 3578-3592 (2007).

[20] Gong, S. Y. et al. Cotton KNL1, encoding a class II KNOX transcription factor, is involved in regulation of fibre development. J. Exp. Bot. 65, 4133-4147 (2014).

[21] Depuydt, S. & Hardtke, C. S. Hormone signalling crosstalk in plant growth regulation. Curr. Biol. 21, R365-R373 (2011).

[22] Klee, H. J. & Giovannoni, J. J. Genetics and control of tomato fruit ripening and quality attributes. Annu. Rev. Genet. 45, 41-59 (2011).

[23] Kimura, S. & Sinha, N. Tomato (Solanum lycopersicum): a model fruit-bearing crop. CSH Protoc. 2008, pdb emo105 (2008).

[24] Huang, Z., Houten, J. V., Gonzalez, G., Han, X. & Knaap, E. V. D. Genome-wide identification, phylogeny and expression analysis of SUN, OFP and YABBY gene family in tomato. Mol. Genet. Genomics 288, 111-129 (2013).

[25] Wu, S. et al. A common genetic mechanism underlies morphological diversity in fruits and other plant organs. Nat. Commun. 9, 4734 (2018).

[26] Zhu, M. et al. A new tomato NAC (NAM/ATAF1/2/CUC2) transcription factor, SlNAC4, functions as a positive regulator of fruit ripening and carotenoid accumulation. Plant Cell Physiol. 55, 119-135 (2014).

[27] Chen, G. et al. Identification of a specific isoform of tomato lipoxygenase (TomloxC) involved in the generation of fatty acid-derived flavor compounds. Plant Physiol. 136, 2641-2651 (2004).

[28] Zhou, S. et al. Manipulation of plant architecture and flowering time by down-regulation of the GRAS transcription factor SlGRAS26 in Solanum lycopersicum. Plant Sci. 271, 81-93 (2018).

[29] Expósito-Rodríguez, M., Borges, A. A., Borges-Pérez, A. & Pérez, J. A. Selection of internal control genes for quantitative real-time RT-PCR studies during tomato development process. BMC Plant Biol. 8, 131 (2008).

[30] Yu, X. et al. The Jasmonate ZIM-domain protein gene SlJAZ2 regulates plant morphology and accelerates flower initiation in Solanum lycopersicum plants. Plant Sci. 267, 65-73 (2018).

[31] Fragkostefanakis, S. et al. HsfA2 controls the activity of developmentally and stress-regulated heat stress protection mechanisms in tomato male reproductive tissues. Plant Physiol. 170, 2461-2477 (2016).

[32] Huang, W. et al. Overexpression of a tomato miR171 target gene SlGRAS24 impacts multiple agronomical traits via regulating gibberellin and auxin homeostasis. Plant Biotechnol. J. 15, 472-488 (2017).

[33] Guo, X. et al. The tomato floral homeotic protein FBP1-like gene, SlGLO1, plays key roles in petal and stamen development. Sci. Rep. 6, 20454 (2016).

[34] Huang, W., Xian, Z., Kang, X., Tang, N. & Li, Z. Genome-wide identification, phylogeny and expression analysis of GRAS gene family in tomato. BMC Plant Biol. 15, 209 (2015).

[35] Noguchi, T. et al. Brassinosteroid-insensitive dwarf mutants of Arabidopsis accumulate brassinosteroids. Plant Physiol. 121, 743-752 (1999).

[36] Xiao, J. et al. Dissection of GA 20-oxidase members affecting tomato morphology by RNAi-mediated silencing. Plant Growth Regul. 50, 179-189 (2006).

[37] Yamaguchi, S. Gibberellin metabolism and its regulation. J. Plant Growth Regul. 20, 317-318 (2001).

[38] Hedden, P. & Kamiya, Y. GIBBERELLIN BIOSYNTHESIS: enzymes, genes and their regulation. Annu. Rev. Plant Physiol. Plant Mol. Biol. 48, 431-460 (1997).

[39] Serrani, J. C., Ruiz-Rivero, O., Fos, M. & Garcia-Martinez, J. L. Auxin-induced fruitset in tomato is mediated in part by gibberellins. Plant J. 56, 922-934 (2008).

[40] Zhang, L. Y. et al. Antagonistic HLH/bHLH transcription factors mediate brassinosteroid regulation of cell elongation and plant development in rice and Arabidopsis. Plant Cell 21, 3767-3780 (2009).

[41] Lee, S. et al. Overexpression of PRE1 and its homologous genes activates Gibberellin-dependent responses in Arabidopsis thaliana. Plant Cell Physiol. 47, 591-600 (2006).

[42] Pnueli, L., Hareven, D., Rounsley, S. D., Yanofsky, M. F. & Lifschitz, E. Isolation of the tomato AGAMOUS gene TAG1 and analysis of its homeotic role in transgenic plants. Plant Cell 6, 163-173 (1994).

[43] Pnueli, L., Hareven, D., Broday, L., Hurwitz, C. & Lifschitz, E. The TM5 MADS box gene mediates organ differentiation in the three inner whorls of tomato flowers. Plant Cell 6, 175-186 (1994).

[44] Ampomahdwamena, C., Morris, B. A., Sutherland, P., Veit, B. & Yao, J. L. Downregulation of TM29, a TomatoSEPALLATA homolog, causes parthenocarpic fruit development and floral reversion. Plant Physiol. 130, 605-617 (2002).

[45] Kim, W. B. et al. Identification of a pollen-specific gene, SlCRK1 (RFK2) in tomato. Genes Genom. 36, 303-311 (2014).

[46] Kim, W. B. et al. SlPMEI, a pollen-specific gene in tomato. Can. J. Plant Sci. 94, 73-83 (2017).

[47] Covey, P. A. et al. A pollen-specific RALF from tomato that regulates pollen tube elongation. Plant Physiol. 153, 703-715 (2010).

[48] Kim, H. U. et al. New pollen-specific receptor kinases identified in tomato, maize and Arabidopsis: the tomato kinases show overlapping but distinct localization patterns on pollen tubes. Plant Mol. Biol. 50, 1-16 (2002).

[49] Tang, W., Ezcurra, I., Muschietti, J. & McCormick, S. A cysteine-rich extracellular protein, LAT52, interacts with the extracellular domain of the pollen receptor kinase LePRK2. Plant Cell 14, 2277 (2002).

[50] Annadana, S. et al. Cloning of the chrysanthemum UEP1 promoter and comparative expression in florets and leaves of Dendranthema grandiflora. Transgenic Res. 11, 437 (2002).

[51] Faktor, O., Kooter, J. M., Dixon, R. A. & Lamb, C. J. Functional dissection of a bean chalcone synthase gene promoter in transgenic tobacco plants reveals sequence motifs essential for floral expression. Plant Mol. Biol. 32, 849-859 (1996).

[52] Yu, D. & Chen, Z. Evidence for an important role of WRKY DNA binding proteins in the regulation of NPR1 gene expression. Plant Cell 13, 1527-1540 (2001).

[53] Rogers, H. J. et al. Functional analysis of cis-regulatory elements within the promoter of the tobacco late pollen gene g10. Plant Mol. Biol. 45, 577-585 (2001).

[54] Xia, X. J. et al. Interplay between reactive oxygen species and hormones in the control of plant development and stress tolerance. J. Exp. Bot. 66, 2839-2856 (2015).

[55] Wang, Z. Y., Zhu, J. Y. & Sae-Seaw, J. Brassinosteroid signaling. Development 140, 1615-1620 (2013).

[56] She, J. et al. Structural insight into brassinosteroid perception by BRI1. Nature 474, 472-477 (2011).

[57] Hothorn, M. et al. Structural basis of steroid hormone perception by the receptor kinase BRI1. Nature 474, 467-472 (2011).

[58] Li, J. & Chory, J. A putative leucine-rich repeat receptor kinase involved in brassinosteroid signal transduction. Cell 90, 929-936 (1997).

[59] Yin, Y. et al. A new class of transcription factors mediates brassinosteroid-regulated gene expression in Arabidopsis. Cell 120, 249-259 (2005).

[60] He, J. X. et al. BZR1 is a transcriptional repressor with dual roles in brassinosteroid homeostasis and growth responses. Science 307, 1634-1638 (2005).

[61] Sato, Y. et al. Abnormal cell divisions in leaf primordia caused by the expression of the rice homeobox gene OSH1 lead to altered morphology of leaves in transgenic tobacco. Mol. Gen. Genet. 251, 13-22 (1996).

[62] Tong, H. et al. DWARF and LOW-TILLERING, a new member of the GRAS family, plays positive roles in brassinosteroid signaling in rice. Plant J. 58, 803-816 (2009).

[63] Tsuda, K., Kurata, N., Ohyanagi, H. & Hake, S. Genome-wide study of KNOX regulatory network reveals brassinosteroid catabolic genes important for shoot meristem function in rice. Plant Cell 26, 3488-3500 (2014).

[64] Chory, J., Nagpal, P. & Peto, C. A. Phenotypic and genetic analysis of det2, a new mutant that affects light-regulated seedling development in Arabidopsis. Plant Cell 3, 445-459 (1991).

[65] Stewart Lilley, J. L., Gan, Y., Graham, I. A. & Nemhauser, J. L. The effects of DELLAs on growth change with developmental stage and brassinosteroid levels. Plant J. 76, 165-173 (2013).

[66] Tong, H. et al. Brassinosteroid regulates cell elongation by modulating gibberellin metabolism in rice. Plant Cell 26, 4376-4393 (2014).

[67] Zhu, Z. et al. Overexpression of SlPRE2, an atypical bHLH transcription factor, affects plant morphology and fruit pigment accumulation in tomato. Sci. Rep. 7, 5786 (2017).

[68] Ruan, Y. L., Patrick, J. W., Bouzayen, M., Osorio, S. & Fernie, A. R. Molecular regulation of seed and fruit set. Trends Plant Sci. 17, 656-665 (2012).

[69] Kim, T. W. et al. Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis. Plant Cell 17, 2397-2412 (2005).

[70] Szekeres, M. et al. Brassinosteroids rescue the deficiency of CYP90, a cytochrome P450, controlling cell elongation and de-etiolation in Arabidopsis. Cell 85, 171-182 (1996).

[71] Ye, Q. et al. Brassinosteroids control male fertility by regulating the expression of key genes involved in Arabidopsis anther and pollen development. Proc. Natl Acad. Sci. USA 107, 6100-6105 (2010).