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Detlef Weigel

Bio: Detlef Weigel is an academic researcher from Max Planck Society. The author has contributed to research in topics: Arabidopsis & Arabidopsis thaliana. The author has an hindex of 142, co-authored 516 publications receiving 84670 citations. Previous affiliations of Detlef Weigel include Ludwig Maximilian University of Munich & California Institute of Technology.


Papers
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Journal ArticleDOI
TL;DR: This work reviews here recent progress made in the understanding of two classes of genes: one class that controls the structural features common to both types of meristems and another class that discriminates between the two types.
Abstract: About 200 years ago, the poet and naturalist Goethe (1790) suggested that flowers were modified shoots and floral organs were modified leaves. In 1991, this assertion was spectacularly confirmed by Bowman et al., who showed that they could transform the sepals, petals, stamens, and carpels of Arabidopsis flowers into leaf-like organs simply by eliminating a set of three floral regulatory genes, AGAMOUS (AG), PISTILLATA (PI), and APETALA2 (AP2). At first it might seem surprising that flowers and shoots are homologous structures, especially when one thinks of such extremes as the tiny flowers of duckweed, barely visible to the naked eye, and the trunk of a mature tree, which can be tens or even hundreds of feet tall. It becomes a little less mysterious if one looks at the earliest stages of development, when flowers or shoots start to arise. Both types of structures are formed from collections of stem cells, termed meristems, which have an organization that is very similar for both flowers and shoots, with at least three domains that can be distinguished by histological and experimental criteria. The central zone, in which cells remain undifferentiated, serves as a stem cell pool for the renewal of the meristem. Surrounding this is the peripheral zone, where new organs are initiated. Underlying the central zone is the rib meristem, which forms the bulk of the interior tissue (Fig. 1). Starting with this common structure, shoot meristems produce leaves with associated axillary shoots and flowers, whereas flower meristems give rise to floral organs such as sepals, petals, stamens, and carpels. Apart from the differences in the types of organs they produce, shoot and flower meristems often differ in phyllotaxis, which is the pattern with which these organs are produced, and in determinacy, which is whether a meristem is consumed in the production of a terminal structure. Given the similarities between flower and shoot meristems, as well as the obvious differences in their subsequent development, one would expect to find at least two classes of genes to be active in early shoot and flower meristems: one class that controls the structural features common to both types of meristems and another class that discriminates between the two types. Both classes of genes have been identified: genes in the first class are called meristem-structure genes and members of the second class are commonly known as meristem-identity genes. Genes in the latter category in turn regulate other factors that elaborate the species-specific differences between shoot and flower meristems. We review here recent progress made in the understanding of these different classes of genes.

23 citations

Journal ArticleDOI
TL;DR: A new mutant allele of the F-box gene HAWAIIAN SKIRT (HWS; At3G61590), hws-5, is identified as a suppressor of the MIM156-induced developmental and molecular phenotypes, proposing HWS as a novel, F-boxes dependent factor involved in miRNA function.
Abstract: As regulators of gene expression in multicellular organisms, microRNAs (miRNAs) are crucial for growth and development. Although a plethora of factors involved in their biogenesis and action in Arabidopsis (Arabidopsis thaliana) has been described, these processes and their fine-tuning are not fully understood. Here, we used plants expressing an artificial miRNA target mimic (MIM) to screen for negative regulators of miR156. We identified a new mutant allele of the F-box gene HAWAIIAN SKIRT (HWS; At3G61590), hws-5, as a suppressor of the MIM156-induced developmental and molecular phenotypes. In hws plants, levels of some endogenous miRNAs are increased and their mRNA targets decreased. Plants constitutively expressing full-length HWS—but not a truncated version lacking the F-box domain—display morphological and molecular phenotypes resembling those of mutants defective in miRNA biogenesis and activity. In combination with such mutants, hws loses its delayed floral organ abscission (“skirt”) phenotype, suggesting epistasis. Also, the hws transcriptome profile partially resembles those of well-known miRNA mutants hyl1-2, se-3, and ago1-27, pointing to a role in a common pathway. We thus propose HWS as a novel, F-box dependent factor involved in miRNA function.

23 citations

Journal ArticleDOI
TL;DR: Results show that LcrLFY has diverged from A.
Abstract: LEAFY (LFY), a transcription factor involved in the regulation of flower development in Arabidopsis thaliana, has been identified as a candidate gene in the diversification of plant architecture in Brassicaceae. Previous research with Leavenworthia crassa, which produces solitary flowers in the axils of rosette leaves, has shown that the L. crassa LFY ortholog, LcrLFY, rescues most aspects of flower development in A. thaliana but showed two novel traits: flowers produced additional petals and inflorescences produced terminal flowers. In this paper, we explore the molecular mechanisms responsible for these novel phenotypes. We used microarray hybridizations to identify 32 genes differentially expressed between a transgenic LcrLFY line and a control transgenic LFY line. Of particular interest, TERMINAL FLOWER 1 (TFL1) transcripts were found at elevated levels in LcrLFY lines. To distinguish regulatory versus functional changes within the LcrLFY locus, reciprocal chimeric transgenes between LcrLFY and LFY were constructed. These lines implicate divergence of LcrLFY cis-regulation as the primary cause of both novel transgenic phenotypes but implicate divergence of LcrLFY protein function as the primary cause of elevated TFL1 levels. Taken together these results show that LcrLFY has diverged from A. thaliana in both the cis-regulatory and protein-coding regions and imply that molecular coevolution of LcrLFY and the L. crassa TFL1 ortholog, LcrTFL1, contributed to the evolution of rosette flowering.

23 citations

Patent
16 Nov 2000
TL;DR: In this article, a method for using enhanced expression of nucleotide sequences encoding a flavin-containing monooxygenase (FMO) and suitable homologs thereof, to elicit desired traits, study biochemical pathways, and oxidize xenobiotics in plants.
Abstract: The present invention provides methods for using enhanced expression of nucleotide sequences encoding a flavin-containing monooxygenase (FMO) and suitable homologs thereof, to elicit desired traits, study biochemical pathways, and oxidize xenobiotics in plants.

22 citations

Posted ContentDOI
23 Nov 2020-bioRxiv
TL;DR: It is proposed that the EDS1-PAD4-ADR1 node is an essential component and convergence point for immune signaling cascades activated by both surface-resident LRR-RP receptors and intracellular NLR receptors.
Abstract: Plants use both cell surface and intracellular immune receptors with leucine rich-repeat (LRRs) to detect pathogens. LRR receptor kinases (LRR-RKs) and LRR receptor-like proteins (LRR-RPs) recognize extracellular microbe-derived molecules to confer pattern-triggered immunity (PTI), while nucleotide-binding LRR (NLR) proteins detect microbial effectors inside the cell to confer effector-triggered immunity (ETI). Despite PTI and ETI signaling being initiated in different compartments, both rely on the transcriptional activation of similar sets of genes, suggesting convergence in signaling upstream of nuclear events. Here we report that two sets of molecules, helper NLRs from the ADR1 (ACTIVATED DISEASE RESISTANCE 1) family as well as lipase-like proteins EDS1 (ENHANCED DISEASE SUSCEPTIBILITY 1) and PAD4 (PHYTOALEXIN DEFICIENT 4), are required not only for ETI, but also for PTI. A further similarity is seen in the evolutionary patterns of some PTI and ETI receptor genes, with both often being highly polymorphic, and with nevertheless distinct roles of LRR-RK and LRR-RP receptors in immunity. We find that the LRR-RK SOBIR1 directly links LRR-RPs with the ADR1 helper NLR as well as EDS1 and PAD4, suggesting the formation of constitutive supramolecular signalosome complexes at the inner side of the plasma membrane. We propose that the EDS1-PAD4-ADR1 node is an essential component and convergence point for immune signaling cascades activated by both surface-resident LRR-RP receptors and intracellular NLR receptors.

22 citations


Cited by
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Journal ArticleDOI
23 Jan 2004-Cell
TL;DR: Although they escaped notice until relatively recently, miRNAs comprise one of the more abundant classes of gene regulatory molecules in multicellular organisms and likely influence the output of many protein-coding genes.

32,946 citations

Journal Article
Fumio Tajima1
30 Oct 1989-Genomics
TL;DR: It is suggested that the natural selection against large insertion/deletion is so weak that a large amount of variation is maintained in a population.

11,521 citations

01 Jun 2012
TL;DR: SPAdes as mentioned in this paper is a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler and on popular assemblers Velvet and SoapDeNovo (for multicell data).
Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.

10,124 citations

Journal Article
TL;DR: For the next few weeks the course is going to be exploring a field that’s actually older than classical population genetics, although the approach it’ll be taking to it involves the use of population genetic machinery.
Abstract: So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

9,847 citations

Journal ArticleDOI
14 Dec 2000-Nature
TL;DR: This is the first complete genome sequence of a plant and provides the foundations for more comprehensive comparison of conserved processes in all eukaryotes, identifying a wide range of plant-specific gene functions and establishing rapid systematic ways to identify genes for crop improvement.
Abstract: The flowering plant Arabidopsis thaliana is an important model system for identifying genes and determining their functions. Here we report the analysis of the genomic sequence of Arabidopsis. The sequenced regions cover 115.4 megabases of the 125-megabase genome and extend into centromeric regions. The evolution of Arabidopsis involved a whole-genome duplication, followed by subsequent gene loss and extensive local gene duplications, giving rise to a dynamic genome enriched by lateral gene transfer from a cyanobacterial-like ancestor of the plastid. The genome contains 25,498 genes encoding proteins from 11,000 families, similar to the functional diversity of Drosophila and Caenorhabditis elegans--the other sequenced multicellular eukaryotes. Arabidopsis has many families of new proteins but also lacks several common protein families, indicating that the sets of common proteins have undergone differential expansion and contraction in the three multicellular eukaryotes. This is the first complete genome sequence of a plant and provides the foundations for more comprehensive comparison of conserved processes in all eukaryotes, identifying a wide range of plant-specific gene functions and establishing rapid systematic ways to identify genes for crop improvement.

8,742 citations