@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} } @misc{NowakRussoSchlapbachetal.2015, author = {Nowak, Michael D. and Russo, Giancarlo and Schlapbach, Ralph and Huu, Cuong Nguyen and Lenhard, Michael and Conti, Elena}, title = {The draft genome of Primula veris yields insights into the molecular basis of heterostyly}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {879}, issn = {1866-8372}, doi = {10.25932/publishup-43508}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435088}, pages = {19}, year = {2015}, abstract = {Background The flowering plant Primula veris is a common spring blooming perennial that is widely cultivated throughout Europe. This species is an established model system in the study of the genetics, evolution, and ecology of heterostylous floral polymorphisms. Despite the long history of research focused on this and related species, the continued development of this system has been restricted due the absence of genomic and transcriptomic resources. Results We present here a de novo draft genome assembly of P. veris covering 301.8 Mb, or approximately 63\% of the estimated 479.22 Mb genome, with an N50 contig size of 9.5 Kb, an N50 scaffold size of 164 Kb, and containing an estimated 19,507 genes. The results of a RADseq bulk segregant analysis allow for the confident identification of four genome scaffolds that are linked to the P. veris S-locus. RNAseq data from both P. veris and the closely related species P. vulgaris allow for the characterization of 113 candidate heterostyly genes that show significant floral morph-specific differential expression. One candidate gene of particular interest is a duplicated GLOBOSA homolog that may be unique to Primula (PveGLO2), and is completely silenced in L-morph flowers. Conclusions The P. veris genome represents the first genome assembled from a heterostylous species, and thus provides an immensely important resource for future studies focused on the evolution and genetic dissection of heterostyly. As the first genome assembled from the Primulaceae, the P. veris genome will also facilitate the expanded application of phylogenomic methods in this diverse family and the eudicots as a whole.}, language = {en} } @misc{JohnsonRammKappeletal.2015, author = {Johnson, Kim L. and Ramm, Sascha and Kappel, Christian and Ward, Sally and Leyser, Ottoline and Sakamoto, Tomoaki and Kurata, Tetsuya and Bevan, Michael W. and Lenhard, Michael}, title = {The tinkerbell (tink) mutation identifies the dual-specificity MAPK phosphatase INDOLE- 3-BUTYRIC ACID-RESPONSE5 (IBR5) as a novel regulator of organ size in Arabidopsis}, series = {PLoS ONE}, journal = {PLoS ONE}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-410245}, pages = {17}, year = {2015}, abstract = {Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways.}, language = {en} } @article{KappelIllingHuuetal.2020, author = {Kappel, Christian and Illing, Nicola and Huu, Cuong Nguyen and Barger, Nichole N. and Cramer, Michael D. and Lenhard, Michael and Midgley, Jeremy J.}, title = {Fairy circles in Namibia are assembled from genetically distinct grasses}, series = {Communications biology}, volume = {3}, journal = {Communications biology}, number = {1}, publisher = {Springer Nature}, address = {London}, issn = {2399-3642}, doi = {10.1038/s42003-020-01431-0}, pages = {8}, year = {2020}, abstract = {Fairy circles are striking regularly sized and spaced, bare circles surrounded by Stipagrostis grasses that occur over thousands of square kilometres in Namibia. The mechanisms explaining their origin, shape, persistence and regularity remain controversial. One hypothesis for the formation of vegetation rings is based on the centrifugal expansion of a single individual grass plant, via clonal growth and die-back in the centre. Clonality could explain FC origin, shape and long-term persistence as well as their regularity, if one clone competes with adjacent clones. Here, we show that for virtually all tested fairy circles the periphery is not exclusively made up of genetically identical grasses, but these peripheral grasses belong to more than one unrelated genet. These results do not support a clonal explanation for fairy circles. Lack of clonality implies that a biological reason for their origin, shape and regularity must emerge from competition between near neighbor individuals within each fairy circle. Such lack of clonality also suggests a mismatch between longevity of fairy circles versus their constituent plants. Furthermore, our findings of lack of clonality have implications for some models of spatial patterning of fairy circles that are based on self-organization. Christian Kappel et al. examine the genetic composition of fairy circles, regular circular patterns of grasses in the Namib Desert, using ddRAD-seq. They find that these grasses are made up of multiple unrelated genets rather than genetically identical grasses, suggesting non-clonality.}, language = {en} } @article{NowakRussoSchlapbachetal.2015, author = {Nowak, Michael D. and Russo, Giancarlo and Schlapbach, Ralph and Cuong Nguyen Huu, and Lenhard, Michael and Conti, Elena}, title = {The draft genome of Primula veris yields insights into the molecular basis of heterostyly}, series = {Genome biology : biology for the post-genomic era}, volume = {16}, journal = {Genome biology : biology for the post-genomic era}, publisher = {BioMed Central}, address = {London}, issn = {1465-6906}, doi = {10.1186/s13059-014-0567-z}, pages = {16}, year = {2015}, abstract = {Background: The flowering plant Primula veris is a common spring blooming perennial that is widely cultivated throughout Europe. This species is an established model system in the study of the genetics, evolution, and ecology of heterostylous floral polymorphisms. Despite the long history of research focused on this and related species, the continued development of this system has been restricted due the absence of genomic and transcriptomic resources. Results: We present here a de novo draft genome assembly of P. veris covering 301.8 Mb, or approximately 63\% of the estimated 479.22 Mb genome, with an N50 contig size of 9.5 Kb, an N50 scaffold size of 164 Kb, and containing an estimated 19,507 genes. The results of a RADseq bulk segregant analysis allow for the confident identification of four genome scaffolds that are linked to the P. veris S-locus. RNAseq data from both P. veris and the closely related species P. vulgaris allow for the characterization of 113 candidate heterostyly genes that show significant floral morph-specific differential expression. One candidate gene of particular interest is a duplicated GLOBOSA homolog that may be unique to Primula (PveGLO2), and is completely silenced in L-morph flowers. Conclusions: The P. veris genome represents the first genome assembled from a heterostylous species, and thus provides an immensely important resource for future studies focused on the evolution and genetic dissection of heterostyly. As the first genome assembled from the Primulaceae, the P. veris genome will also facilitate the expanded application of phylogenomic methods in this diverse family and the eudicots as a whole.}, language = {en} } @article{JohnsonRammKappeletal.2015, author = {Johnson, Kim L. and Ramm, Sascha and Kappel, Christian and Ward, Sally and Leyser, Ottoline and Sakamoto, Tomoaki and Kurata, Tetsuya and Bevan, Michael W. and Lenhard, Michael}, title = {The Tinkerbell (Tink) Mutation Identifies the Dual-Specificity MAPK Phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) as a Novel Regulator of Organ Size in Arabidopsis}, series = {PLoS one}, volume = {10}, journal = {PLoS one}, number = {7}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0131103}, pages = {17}, year = {2015}, abstract = {Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways.}, language = {en} } @article{KahlLenhardJoshi2019, author = {Kahl, Sandra and Lenhard, Michael and Joshi, Jasmin Radha}, title = {Compensatory mechanisms to climate change in the widely distributed species Silene vulgaris}, series = {The journal of ecology}, volume = {107}, journal = {The journal of ecology}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {0022-0477}, doi = {10.1111/1365-2745.13133}, pages = {1918 -- 1930}, year = {2019}, abstract = {The adaptation of plants to future climatic conditions is crucial for their survival. Not surprisingly, phenotypic responses to climate change have already been observed in many plant populations. These responses may be due to evolutionary adaptive changes or phenotypic plasticity. Especially plant species with a wide geographic range are either expected to show genetic differentiation in response to differing climate conditions or to have a high phenotypic plasticity. We investigated phenotypic responses and plasticity as an estimate of the adaptive potential in the widespread species Silene vulgaris. In a greenhouse experiment, 25 European populations covering a geographic range from the Canary Islands to Sweden were exposed to three experimental precipitation and two temperature regimes mimicking a possible climate-change scenario for central Europe. We hypothesized that southern populations have a better performance under high temperature and drought conditions, as they are already adapted to a comparable environment. We found that our treatments significantly influenced the plants, but did not reveal a latitudinal difference in response to climate treatments for most plant traits. Only flower number showed a stronger plasticity in northern European populations (e.g. Swedish populations) where numbers decreased more drastically with increased temperature and decreased precipitation treatment. Synthesis. The significant treatment response in Silene vulgaris, independent of population origin - except for the number of flowers produced - suggests a high degree of universal phenotypic plasticity in this widely distributed species. This reflects the likely adaptation strategy of the species and forms the basis for a successful survival strategy during upcoming climatic changes. However, as flower number, a strongly fitness-related trait, decreased more strongly in northern populations under a climate-change scenario, there might be limits to adaptation even in this widespread, plastic species.}, language = {en} } @misc{KahlKappelJoshietal.2021, author = {Kahl, Sandra and Kappel, Christian and Joshi, Jasmin Radha and Lenhard, Michael}, title = {Phylogeography of a widely distributed plant species reveals cryptic genetic lineages with parallel phenotypic responses to warming and drought conditions}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, issn = {1866-8372}, doi = {10.25932/publishup-53003}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-530035}, pages = {13986 -- 14002}, year = {2021}, abstract = {To predict how widely distributed species will perform under future climate change, it is crucial to understand and reveal their underlying phylogenetics. However, detailed information about plant adaptation and its genetic basis and history remains scarce and especially widely distributed species receive little attention despite their putatively high adaptability. To examine the adaptation potential of a widely distributed species, we sampled the model plant Silene vulgaris across Europe. In a greenhouse experiment, we exposed the offspring of these populations to a climate change scenario for central Europe and revealed the population structure through whole-genome sequencing. Plants were grown under two temperatures (18°C and 21°C) and three precipitation regimes (65, 75, and 90 mm) to measure their response in biomass and fecundity-related traits. To reveal the population genetic structure, ddRAD sequencing was employed for a whole-genome approach. We found three major genetic clusters in S. vulgaris from Europe: one cluster comprising Southern European populations, one cluster of Western European populations, and another cluster containing central European populations. Population genetic diversity decreased with increasing latitude, and a Mantel test revealed significant correlations between FST and geographic distances as well as between genetic and environmental distances. Our trait analysis showed that the genetic clusters significantly differed in biomass-related traits and in the days to flowering. However, half of the traits showed parallel response patterns to the experimental climate change scenario. Due to the differentiated but parallel response patterns, we assume that phenotypic plasticity plays an important role for the adaptation of the widely distributed species S. vulgaris and its intraspecific genetic lineages.}, language = {en} } @article{SicardThammMaronaetal.2014, author = {Sicard, Adrien and Thamm, Anna and Marona, Cindy and Lee, Young Wha and Wahl, Vanessa and Stinchcombe, John R. and Wright, Stephen I. and Kappel, Christian and Lenhard, Michael}, title = {Repeated evolutionary changes of leaf morphology caused by mutations to a homeobox gene}, series = {Current biology}, volume = {24}, journal = {Current biology}, number = {16}, publisher = {Cell Press}, address = {Cambridge}, issn = {0960-9822}, doi = {10.1016/j.cub.2014.06.061}, pages = {1880 -- 1886}, year = {2014}, abstract = {Elucidating the genetic basis of morphological changes in evolution remains a major challenge in biology [1-3]. Repeated independent trait changes are of particular interest because they can indicate adaptation in different lineages or genetic and developmental constraints on generating morphological variation [4-6]. In animals, changes to "hot spot" genes with minimal pleiotropy and large phenotypic effects underlie many cases of repeated morphological transitions [4-8]. By contrast, only few such genes have been identified from plants [8-11], limiting cross-kingdom comparisons of the principles of morphological evolution. Here, we demonstrate that the REDUCED COMPLEXITY (RCO) locus [12] underlies more than one naturally evolved change in leaf shape in the Brassicaceae. We show that the difference in leaf margin dissection between the sister species Capsella rubella and Capsella grandiflora is caused by cis-regulatory variation in the homeobox gene RCO-A, which alters its activity in the developing lobes of the leaf. Population genetic analyses in the ancestral C. grandiflora indicate that the more-active C. rubella haplotype is derived from a now rare or lost C. grandiflora haplotype via additional mutations. In Arabidopsis thaliana, the deletion of the RCO-A and RCO-B genes has contributed to its evolutionarily derived smooth leaf margin [12], suggesting the RCO locus as a candidate for an evolutionary hot spot. We also find that temperature-responsive expression of RCO-A can explain the phenotypic plasticity of leaf shape to ambient temperature in Capsella, suggesting a molecular basis for the well-known negative correlation between temperature and leaf margin dissection.}, language = {en} } @article{GrafDolzblaszWuerschumetal.2010, author = {Graf, Philipp and Dolzblasz, Alicja and W{\"u}rschum, Tobias and Lenhard, Michael and Pfreundt, Ulrike and Laux, Thomas}, title = {MGOUN1 encodes an Arabidopsis type Ib DNA topoisomerase required in stem cell regulation and to maintain develpmentally regulated gene silencing}, issn = {1040-4651}, year = {2010}, language = {en} } @misc{SicardKappelJosephsetal.2015, author = {Sicard, Adrien and Kappel, Christian and Josephs, Emily B. and Wha Lee, Young and Marona, Cindy and Stinchcombe, John R. and Wright, Stephen I. and Lenhard, Michael}, title = {Divergent sorting of a balanced ancestral polymorphism underlies the establishment of gene-flow barriers in Capsella}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93568}, year = {2015}, abstract = {In the Bateson-Dobzhansky-Muller model of genetic incompatibilities post-zygotic gene-flow barriers arise by fixation of novel alleles at interacting loci in separated populations. Many such incompatibilities are polymorphic in plants, implying an important role for genetic drift or balancing selection in their origin and evolution. Here we show that NPR1 and RPP5 loci cause a genetic incompatibility between the incipient species Capsella grandiflora and C. rubella, and the more distantly related C. rubella and C. orientalis. The incompatible RPP5 allele results from a mutation in C. rubella, while the incompatible NPR1 allele is frequent in the ancestral C. grandiflora. Compatible and incompatible NPR1 haplotypes are maintained by balancing selection in C. grandiflora, and were divergently sorted into the derived C. rubella and C. orientalis. Thus, by maintaining differentiated alleles at high frequencies, balancing selection on ancestral polymorphisms can facilitate establishing gene-flow barriers between derived populations through lineage sorting of the alternative alleles.}, language = {en} } @misc{JantzenWozniakKappeletal.2019, author = {Jantzen, Friederike and Wozniak, Natalia Joanna and Kappel, Christian and Sicard, Adrien and Lenhard, Michael}, title = {A high‑throughput amplicon‑based method for estimating outcrossing rates}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {745}, issn = {1866-8372}, doi = {10.25932/publishup-43565}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435657}, pages = {14}, year = {2019}, abstract = {Background: The outcrossing rate is a key determinant of the population-genetic structure of species and their long-term evolutionary trajectories. However, determining the outcrossing rate using current methods based on PCRgenotyping individual offspring of focal plants for multiple polymorphic markers is laborious and time-consuming. Results: We have developed an amplicon-based, high-throughput enabled method for estimating the outcrossing rate and have applied this to an example of scented versus non-scented Capsella (Shepherd's Purse) genotypes. Our results show that the method is able to robustly capture differences in outcrossing rates. They also highlight potential biases in the estimates resulting from differential haplotype sharing of the focal plants with the pollen-donor population at individual amplicons. Conclusions: This novel method for estimating outcrossing rates will allow determining this key population-genetic parameter with high-throughput across many genotypes in a population, enabling studies into the genetic determinants of successful pollinator attraction and outcrossing.}, 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{TrostViCzesnicketal.2014, author = {Trost, Gerda and Vi, Son Lang and Czesnick, Hj{\"o}rdis and Lange, Peggy and Holton, Nick and Giavalisco, Patrick and Zipfel, Cyril and Kappel, Christian and Lenhard, Michael}, title = {Arabidopsis poly(A) polymerase PAPS1 limits founder-cell recruitment to organ primordia and suppresses the salicylic acid-independent immune response downstream of EDS1/PAD4}, series = {The plant journal}, volume = {77}, journal = {The plant journal}, number = {5}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0960-7412}, doi = {10.1111/tpj.12421}, pages = {688 -- 699}, year = {2014}, abstract = {Polyadenylation of pre-mRNAs by poly(A) polymerase (PAPS) is a critical process in eukaryotic gene expression. As found in vertebrates, plant genomes encode several isoforms of canonical nuclear PAPS enzymes. In Arabidopsis thaliana these isoforms are functionally specialized, with PAPS1 affecting both organ growth and immune response, at least in part by the preferential polyadenylation of subsets of pre-mRNAs. Here, we demonstrate that the opposite effects of PAPS1 on leaf and flower growth reflect the different identities of these organs, and identify a role for PAPS1 in the elusive connection between organ identity and growth patterns. The overgrowth of paps1 mutant petals is due to increased recruitment of founder cells into early organ primordia, and suggests that PAPS1 activity plays unique roles in influencing organ growth. By contrast, the leaf phenotype of paps1 mutants is dominated by a constitutive immune response that leads to increased resistance to the biotrophic oomycete Hyaloperonospora arabidopsidis and reflects activation of the salicylic acid-independent signalling pathway downstream of ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)/PHYTOALEXIN DEFICIENT4 (PAD4). These findings provide an insight into the developmental and physiological basis of the functional specialization amongst plant PAPS isoforms.}, language = {en} } @misc{SicardLenhard2011, author = {Sicard, Adrien and Lenhard, Michael}, title = {The selfing syndrome a model for studying the genetic and evolutionary basis of morphological adaptation in plants}, series = {Annals of botany}, volume = {107}, journal = {Annals of botany}, number = {9}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0305-7364}, doi = {10.1093/aob/mcr023}, pages = {1433 -- 1443}, year = {2011}, abstract = {Background In angiosperm evolution, autogamously selfing lineages have been derived from outbreeding ancestors multiple times, and this transition is regarded as one of the most common evolutionary tendencies in flowering plants. In most cases, it is accompanied by a characteristic set of morphological and functional changes to the flowers, together termed the selfing syndrome. Two major areas that have changed during evolution of the selfing syndrome are sex allocation to male vs. female function and flower morphology, in particular flower (mainly petal) size and the distance between anthers and stigma. Scope A rich body of theoretical, taxonomic, ecological and genetic studies have addressed the evolutionary modification of these two trait complexes during or after the transition to selfing. Here, we review our current knowledge about the genetics and evolution of the selfing syndrome. Conclusions We argue that because of its frequent parallel evolution, the selfing syndrome represents an ideal model for addressing basic questions about morphological evolution and adaptation in flowering plants, but that realizing this potential will require the molecular identification of more of the causal genes underlying relevant trait variation.}, language = {en} } @article{KappelFriedrichOberkofleretal.2023, author = {Kappel, Christian and Friedrich, Thomas and Oberkofler, Vicky and Jiang, Li and Crawford, Tim and Lenhard, Michael and B{\"a}urle, Isabel}, title = {Genomic and epigenomic determinants of heat stress-induced transcriptional memory in Arabidopsis}, series = {Genome biology : biology for the post-genomic era}, volume = {24}, journal = {Genome biology : biology for the post-genomic era}, number = {1}, publisher = {BioMed Central}, address = {London}, issn = {1474-760X}, doi = {10.1186/s13059-023-02970-5}, pages = {23}, year = {2023}, abstract = {Background Transcriptional regulation is a key aspect of environmental stress responses. Heat stress induces transcriptional memory, i.e., sustained induction or enhanced re-induction of transcription, that allows plants to respond more efficiently to a recurrent HS. In light of more frequent temperature extremes due to climate change, improving heat tolerance in crop plants is an important breeding goal. However, not all heat stress-inducible genes show transcriptional memory, and it is unclear what distinguishes memory from non-memory genes. To address this issue and understand the genome and epigenome architecture of transcriptional memory after heat stress, we identify the global target genes of two key memory heat shock transcription factors, HSFA2 and HSFA3, using time course ChIP-seq. Results HSFA2 and HSFA3 show near identical binding patterns. In vitro and in vivo binding strength is highly correlated, indicating the importance of DNA sequence elements. In particular, genes with transcriptional memory are strongly enriched for a tripartite heat shock element, and are hallmarked by several features: low expression levels in the absence of heat stress, accessible chromatin environment, and heat stress-induced enrichment of H3K4 trimethylation. These results are confirmed by an orthogonal transcriptomic data set using both de novo clustering and an established definition of memory genes. Conclusions Our findings provide an integrated view of HSF-dependent transcriptional memory and shed light on its sequence and chromatin determinants, enabling the prediction and engineering of genes with transcriptional memory behavior.}, language = {en} } @misc{JohnsonLenhard2011, author = {Johnson, Kim L. and Lenhard, Michael}, title = {Genetic control of plant organ growth}, series = {New phytologist : international journal of plant science}, volume = {191}, journal = {New phytologist : international journal of plant science}, number = {2}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0028-646X}, doi = {10.1111/j.1469-8137.2011.03737.x}, pages = {319 -- 333}, year = {2011}, abstract = {The growth of plant organs is under genetic control. Work in model species has identified a considerable number of genes that regulate different aspects of organ growth. This has led to an increasingly detailed knowledge about how the basic cellular processes underlying organ growth are controlled, and which factors determine when proliferation gives way to expansion, with this transition emerging as a critical decision point during primordium growth. Progress has been made in elucidating the genetic basis of allometric growth and the role of tissue polarity in shaping organs. We are also beginning to understand how the mechanisms that determine organ identity influence local growth behaviour to generate organs with characteristic sizes and shapes. Lastly, growth needs to be coordinated at several levels, for example between different cell layers and different regions within one organ, and the genetic basis for such coordination is being elucidated. However, despite these impressive advances, a number of basic questions are still not fully answered, for example, whether and how a growing primordium keeps track of its size. Answering these questions will likely depend on including additional approaches that are gaining in power and popularity, such as combined live imaging and modelling.}, language = {en} } @misc{GuentherScholzZimmermannetal.2016, author = {G{\"u}nther, Oliver and Scholz, Jana and Zimmermann, Matthias and Lang, Agnetha and Kampe, Heike and Horn-Conrad, Antje and Eckardt, Barbara and Pohlmann, Markus and Engel, Silke and Hackel, Manuela and Lenhard, Michael and Schwarz, Wolfgang}, title = {Portal = Schillernd, sensibel, kraftvoll: Meere und Ozeane}, number = {03/2016}, organization = {Universit{\"a}t Potsdam, Referat f{\"u}r Presse- und {\"O}ffentlichkeitsarbeit}, issn = {1618-6893}, doi = {10.25932/publishup-44067}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-440678}, pages = {46}, year = {2016}, abstract = {Aus dem Inhalt: - Schillernd, sensibel, kraftvoll: Meere und Ozeane - Erdoberfl{\"a}che im Fokus - Reine Theorie}, language = {de} } @misc{KappelTrostCzesnicketal.2015, author = {Kappel, Christian and Trost, Gerda and Czesnick, Hj{\"o}rdis and Ramming, Anna and Kolbe, Benjamin and Vi, Song Lang and Bispo, Cl{\´a}udia and Becker, J{\"o}rg D. and de Moor, Cornelia and Lenhard, Michael}, title = {Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A) Polymerases in Arabidopsis thaliana}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96400}, pages = {1 -- 30}, year = {2015}, abstract = {The poly(A) tail at 3' ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A)-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A)-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A)-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A)-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A)-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression.}, language = {en} } @misc{SasMuellerKappeletal.2016, author = {Sas, Claudia and M{\"u}ller, Frank and Kappel, Christian and Kent, Tyler V. and Wright, Stephen I. and Hilker, Monika and Lenhard, Michael}, title = {Repeated inactivation of the first committed enzyme underlies the loss of benzaldehyde emission after the selfing transition in Capsella}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {904}, issn = {1866-8372}, doi = {10.25932/publishup-43801}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-438018}, pages = {3313 -- 3319}, year = {2016}, abstract = {The enormous species richness of flowering plants is at least partly due to floral diversification driven by interactions between plants and their animal pollinators [1, 2]. Specific pollinator attraction relies on visual and olfactory floral cues [3-5]; floral scent can not only attract pollinators but also attract or repel herbivorous insects [6-8]. However, despite its central role for plant-animal interactions, the genetic control of floral scent production and its evolutionary modification remain incompletely understood [9-13]. Benzenoids are an important class of floral scent compounds that are generated from phenylalanine via several enzymatic pathways [14-17]. Here we address the genetic basis of the loss of floral scent associated with the transition from outbreeding to selfing in the genus Capsella. While the outbreeding C. grandiflora emits benzaldehyde as a major constituent of its floral scent, this has been lost in the selfing C. rubella. We identify the Capsella CNL1 gene encoding cinnamate: CoA ligase as responsible for this variation. Population genetic analysis indicates that CNL1 has been inactivated twice independently in C. rubella via different novel mutations to its coding sequence. Together with a recent study in Petunia [18], this identifies cinnamate: CoA ligase as an evolutionary hotspot for mutations causing the loss of benzenoid scent compounds in association with a shift in the reproductive strategy of Capsella from pollination by insects to self-fertilization.}, language = {en} }