@article{AbdirashidLenhard2020,
  author    = {Abdirashid, Hashim and Lenhard, Michael},
  title     = {Say it with double flowers},
  series = {Journal of experimental botany},
  volume    = {71},
  journal   = {Journal of experimental botany},
  number    = {9},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0022-0957},
  doi       = {10.1093/jxb/eraa109},
  pages     = {2469 -- 2471},
  year      = {2020},
  abstract  = {Every year, lovers world-wide rely on mutants to show their feelings on Valentine's Day. This is because many of the most popular ornamental flowering plants have been selected to form extra petals at the expense of reproductive organs to enhance their attractiveness and aesthetic value to humans. This so-called 'double flower' (DF) phenotype, first described more than 2000 years ago (Meyerowitz et al., 1989) is present, for example, in many modern roses, carnations, peonies, and camellias. Gattolin et al. (2020) now identify a unifying explanation for the molecular basis of many of these DF cultivars.},
  language  = {en}
}
@misc{BartholomaeusLenhard2019,
  author    = {Bartholom{\"a}us, Lisa and Lenhard, Michael},
  title     = {Plant Biology: Learning to Love Yourself},
  series = {Current biology},
  volume    = {29},
  journal   = {Current biology},
  number    = {14},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {0960-9822},
  doi       = {10.1016/j.cub.2019.06.015},
  pages     = {R695 -- R697},
  year      = {2019},
  abstract  = {In self-incompatible plants the female style rejects self pollen, yet the extent to which the female style in the many self-compatible species can still select between different pollen genotypes and thus bias fertilization success is unclear. A new study identifies the molecular basis for how styles of the self-compatible coyote tobacco bias the fertilization success of pollen genotypes using matching gene expression patterns in a manner analogous to cryptic female choice in animals.},
  language  = {en}
}
@article{BollierSicardLeblondetal.2018,
  author    = {Bollier, Norbert and Sicard, Adrien and Leblond, Julie and Latrasse, David and Gonzalez, Nathalie and Gevaudant, Frederic and Benhamed, Moussa and Raynaud, Cecile and Lenhard, Michael and Chevalier, Christian and Hernould, Michel and Delmas, Frederic},
  title     = {At-MINI ZINC FINGER2 and Sl-INHIBITOR OF MERISTEM ACTIVITY, a Conserved Missing Link in the Regulation of Floral Meristem Termination in Arabidopsis and Tomato},
  series = {The plant cell},
  volume    = {30},
  journal   = {The plant cell},
  number    = {1},
  publisher = {American Society of Plant Physiologists},
  address   = {Rockville},
  issn      = {1040-4651},
  doi       = {10.1105/tpc.17.00653},
  pages     = {83 -- 100},
  year      = {2018},
  abstract  = {In angiosperms, the gynoecium is the last structure to develop within the flower due to the determinate fate of floral meristem (FM) stem cells. The maintenance of stem cell activity before its arrest at the stage called FM termination affects the number of carpels that develop. The necessary inhibition at this stage of WUSCHEL (WUS), which is responsible for stem cell maintenance, involves a two-step mechanism. Direct repression mediated by the MADS domain transcription factor AGAMOUS (AG), followed by indirect repression requiring the C2H2 zinc-finger protein KNUCKLES (KNU), allow for the complete termination of floral stem cell activity. Here, we show that Arabidopsis thaliana MINI ZINC FINGER2 (AtMIF2) and its homolog in tomato (Solanum lycopersicum), INHIBITOR OF MERISTEM ACTIVITY (SlIMA), participate in the FM termination process by functioning as adaptor proteins. AtMIF2 and SlIMA recruit AtKNU and SlKNU, respectively, to form a transcriptional repressor complex together with TOPLESS and HISTONE DEACETYLASE19. AtMIF2 and SlIMA bind to the WUS and SIWUS loci in the respective plants, leading to their repression. These results provide important insights into the molecular mechanisms governing (FM) termination and highlight the essential role of AtMIF2/SlIMA during this developmental step, which determines carpel number and therefore fruit size.},
  language  = {en}
}
@article{BreuningerLenhard2010,
  author    = {Breuninger, Holger and Lenhard, Michael},
  title     = {Control of tissue and organ growth in plants},
  issn      = {0070-2153},
  year      = {2010},
  language  = {en}
}
@misc{BreuningerLenhard2017,
  author    = {Breuninger, Holger and Lenhard, Michael},
  title     = {Expression of the central growth regulator BIG BROTHER is regulated by multiple cis-elements},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-400971},
  pages     = {10},
  year      = {2017},
  abstract  = {Background Much of the organismal variation we observe in nature is due to differences in organ size. The observation that even closely related species can show large, stably inherited differences in organ size indicates a strong genetic component to the control of organ size. Despite recent progress in identifying factors controlling organ growth in plants, our overall understanding of this process remains limited, partly because the individual factors have not yet been connected into larger regulatory pathways or networks. To begin addressing this aim, we have studied the upstream regulation of expression of BIG BROTHER (BB), a central growth-control gene in Arabidopsis thaliana that prevents overgrowth of organs. Final organ size and BB expression levels are tightly correlated, implying the need for precise control of its expression. BB expression mirrors proliferative activity, yet the gene functions to limit proliferation, suggesting that it acts in an incoherent feedforward loop downstream of growth activators to prevent over-proliferation. Results To investigate the upstream regulation of BB we combined a promoter deletion analysis with a phylogenetic footprinting approach. We were able to narrow down important, highly conserved, cis-regulatory elements within the BB promoter. Promoter sequences of other Brassicaceae species were able to partially complement the A. thaliana bb-1 mutant, suggesting that at least within the Brassicaceae family the regulatory pathways are conserved. Conclusions This work underlines the complexity involved in precise quantitative control of gene expression and lays the foundation for identifying important upstream regulators that determine BB expression levels and thus final organ size.},
  language  = {en}
}
@article{CuongNguyenHuuKappelKelleretal.2016,
  author    = {Cuong Nguyen Huu, and Kappel, Christian and Keller, Barbara and Sicard, Adrien and Takebayashi, Yumiko and Breuninger, Holger and Nowak, Michael D. and B{\"a}urle, Isabel and Himmelbach, Axel and Burkart, Michael and Ebbing-Lohaus, Thomas and Sakakibara, Hitoshi and Altschmied, Lothar and Conti, Elena and Lenhard, Michael},
  title     = {Presence versus absence of CYP734A50 underlies the style-length dimorphism in primroses},
  series = {eLife},
  volume    = {5},
  journal   = {eLife},
  publisher = {eLife Sciences Publications},
  address   = {Cambridge},
  issn      = {2050-084X},
  doi       = {10.7554/eLife.17956},
  pages     = {15},
  year      = {2016},
  abstract  = {Heterostyly is a wide-spread floral adaptation to promote outbreeding, yet its genetic basis and evolutionary origin remain poorly understood. In Primula (primroses), heterostyly is controlled by the S-locus supergene that determines the reciprocal arrangement of reproductive organs and incompatibility between the two morphs. However, the identities of the component genes remain unknown. Here, we identify the Primula CYP734A50 gene, encoding a putative brassinosteroid-degrading enzyme, as the G locus that determines the style-length dimorphism. CYP734A50 is only present on the short-styled S-morph haplotype, it is specifically expressed in S-morph styles, and its loss or inactivation leads to long styles. The gene arose by a duplication specific to the Primulaceae lineage and shows an accelerated rate of molecular evolution. Thus, our results provide a mechanistic explanation for the Primula style-length dimorphism and begin to shed light on the evolution of the S-locus as a prime model for a complex plant supergene.},
  language  = {en}
}
@article{CzesnickLenhard2015,
  author    = {Czesnick, Hj{\"o}rdis and Lenhard, Michael},
  title     = {Size Control in Plants-Lessons from Leaves and Flowers},
  series = {Cold Spring Harbor perspectives in biology},
  volume    = {7},
  journal   = {Cold Spring Harbor perspectives in biology},
  number    = {8},
  publisher = {Cold Spring Harbor Laboratory Press},
  address   = {Cold Spring Harbor, NY},
  issn      = {1943-0264},
  doi       = {10.1101/cshperspect.a019190},
  pages     = {16},
  year      = {2015},
  abstract  = {To achieve optimal functionality, plant organs like leaves and petals have to grow to a certain size. Beginning with a limited number of undifferentiated cells, the final size of an organ is attained by a complex interplay of cell proliferation and subsequent cell expansion. Regulatory mechanisms that integrate intrinsic growth signals and environmental cues are required to enable optimal leaf and flower development. This review focuses on plant-specific principles of growth reaching from the cellular to the organ level. The currently known genetic pathways underlying these principles are summarized and network connections are highlighted. Putative non-cell autonomously acting mechanisms that might coordinate plant-cell growth are discussed.},
  language  = {en}
}
@article{CzesnickLenhard2016,
  author    = {Czesnick, Hj{\"o}rdis and Lenhard, Michael},
  title     = {Antagonistic control of flowering time by functionally specialized poly(A) polymerases in Arabidopsis thaliana},
  series = {The plant journal},
  volume    = {88},
  journal   = {The plant journal},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0960-7412},
  doi       = {10.1111/tpj.13280},
  pages     = {570 -- 583},
  year      = {2016},
  abstract  = {Polyadenylation is a critical 3-end processing step during maturation of pre-mRNAs, and the length of the poly(A) tail affects mRNA stability, nuclear export and translation efficiency. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerase (PAPS) isoforms fulfilling specialized functions, as reflected by their different mutant phenotypes. While PAPS1 affects several processes, such as the immune response, organ growth and male gametophyte development, the roles of PAPS2 and PAPS4 are largely unknown. Here we demonstrate that PAPS2 and PAPS4 promote flowering in a partially redundant manner. The enzymes act antagonistically to PAPS1, which delays the transition to flowering. The opposite flowering-time phenotypes in paps1 and paps2 paps4 mutants are at least partly due to decreased or increased FLC activity, respectively. In contrast to paps2 paps4 mutants, plants with increased PAPS4 activity flower earlier than the wild-type, concomitant with reduced FLC expression. Double mutant analyses suggest that PAPS2 and PAPS4 act independently of the autonomous pathway components FCA, FY and CstF64. The direct polyadenylation targets of the three PAPS isoforms that mediate their effects on flowering time do not include FLC sense mRNA and remain to be identified. Thus, our results uncover a role for canonical PAPS isoforms in flowering-time control, raising the possibility that modulating the balance of the isoform activities could be used to fine tune the transition to flowering. Significance Statement The length of the poly(A) tail affects mRNA stability, nuclear export and translation efficiency. Arabidopsis has three isoforms of nuclear poly(A) polymerase (PAPS): PAPS1 plays a major role in organ growth and plant defence. Here we show that PAPS2 and PAPS4 redundantly promote flowering and act antagonistically to PAPS1, which delays flowering. We suggest that modulating the activity of these isoforms fine-tunes the transition to flowering.},
  language  = {en}
}
@article{EldridgeLangowskiStaceyetal.2016,
  author    = {Eldridge, Tilly and Langowski, Lukasz and Stacey, Nicola and Jantzen, Friederike and Moubayidin, Laila and Sicard, Adrien and Southam, Paul and Kennaway, Richard and Lenhard, Michael and Coen, Enrico S. and Ostergaard, Lars},
  title     = {Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy},
  series = {Development : Company of Biologists},
  volume    = {143},
  journal   = {Development : Company of Biologists},
  publisher = {Company of Biologists Limited},
  address   = {Cambridge},
  issn      = {0950-1991},
  doi       = {10.1242/dev.135327},
  pages     = {3394 -- 3406},
  year      = {2016},
  abstract  = {Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity.},
  language  = {en}
}
@misc{EldridgeŁangowskiStaceyetal.2016,
  author    = {Eldridge, Tilly and Łangowski, Łukasz and Stacey, Nicola and Jantzen, Friederike and Moubayidin, Laila and Sicard, Adrien and Southam, Paul and Kennaway, Richard and Lenhard, Michael and Coen, Enrico S. and {\O}stergaard, Lars},
  title     = {Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {986},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43804},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438041},
  pages     = {3394 -- 3406},
  year      = {2016},
  abstract  = {Fruits exhibit a vast array of different 3D shapes, from simple spheres and cylinders to more complex curved forms; however, the mechanism by which growth is oriented and coordinated to generate this diversity of forms is unclear. Here, we compare the growth patterns and orientations for two very different fruit shapes in the Brassicaceae: the heart-shaped Capsella rubella silicle and the near-cylindrical Arabidopsis thaliana silique. We show, through a combination of clonal and morphological analyses, that the different shapes involve different patterns of anisotropic growth during three phases. These experimental data can be accounted for by a tissue level model in which specified growth rates vary in space and time and are oriented by a proximodistal polarity field. The resulting tissue conflicts lead to deformation of the tissue as it grows. The model allows us to identify tissue-specific and temporally specific activities required to obtain the individual shapes. One such activity may be provided by the valve-identity gene FRUITFULL, which we show through comparative mutant analysis to modulate fruit shape during post-fertilisation growth of both species. Simple modulations of the model presented here can also broadly account for the variety of shapes in other Brassicaceae species, thus providing a simplified framework for fruit development and shape diversity.},
  language  = {en}
}