scholarly journals Spring flowering habit in field pennycress (Thlaspi arvense) has arisen multiple independent times

2017 ◽  
Author(s):  
Kevin M. Dorn ◽  
Evan B. Johnson ◽  
Erin Daniels ◽  
Donald L. Wyse ◽  
M. David Marks

Summary- Pennycress (Thlaspi arvense L.) is currently being developed as a new cold-season oilseed crop. Like many Brassicaceae, pennycress can exhibit either a winter or spring annual phenotype. In Arabidopsis, mutations in negative regulators of flowering, including FLOWERING LOCUS C (FLC) and FRIGIDA can cause the transition to a spring annual habit. The genetics underlying the difference between spring and winter annual pennycress are currently unknown.- Using whole genome sequencing across wild spring annual pennycress accessions, co-segregation analyses, and comparative genomics approaches, we identify new alleles of TaFLC and explore their geographic distribution.- We report that loss of function mutations in TaFLC confer the spring annual phenotype in pennycress. We have also identified four natural alleles of TaFLC that confer a spring annual growth habit. The two spring annual FLC alleles present in European accessions were only identified in accessions collected in Montana, USA.- In pennycress, the spring annual habit has arisen several independent times. Accessions harboring the two European alleles were introduced to North America, likely after the species became a widespread on the continent. These findings provide new information on the natural history of the introduction and spread of the spring annual phenotype in pennycress.

Author(s):  
Greg F. W. Gocal

AbstractThe genome of Brassica napus L. is the result of several polyploidization events that occurred during the history of B. napus. Due to its relatively short domestication history, diversity is relatively limited. An increasing number of loci in this crop’s genome have been gene-edited using various technologies and reagent delivery methods for basic research as well as for trait development. New alleles have been developed as edits in single, 2, 4, or more homologous loci in this important oilseed crop. This comprehensive review will summarize new alleles that have been developed as they relate to weed control, flowering, self-incompatibility, plant hormone biology, disease resistance, grain composition, and pod shatter reduction. These new alleles have significantly augmented our understanding of both plant growth and development for basic research as well as for their potential commercial impacts.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yupeng Geng ◽  
Yabin Guan ◽  
La Qiong ◽  
Shugang Lu ◽  
Miao An ◽  
...  

Abstract Background Understanding how organisms evolve and adapt to extreme habitats is of crucial importance in evolutionary ecology. Altitude gradients are an important determinant of the distribution pattern and range of organisms due to distinct climate conditions at different altitudes. High-altitude regions often provide extreme environments including low temperature and oxygen concentration, poor soil, and strong levels of ultraviolet radiation, leading to very few plant species being able to populate elevation ranges greater than 4000 m. Field pennycress (Thlaspi arvense) is a valuable oilseed crop and emerging model plant distributed across an elevation range of nearly 4500 m. Here, we generate an improved genome assembly to understand how this species adapts to such different environments. Results We sequenced and assembled de novo the chromosome-level pennycress genome of 527.3 Mb encoding 31,596 genes. Phylogenomic analyses based on 2495 single-copy genes revealed that pennycress is closely related to Eutrema salsugineum (estimated divergence 14.32–18.58 Mya), and both species form a sister clade to Schrenkiella parvula and genus Brassica. Field pennycress contains the highest percentage (70.19%) of transposable elements in all reported genomes of Brassicaceae, with the retrotransposon proliferation in the Middle Pleistocene being likely responsible for the expansion of genome size. Moreover, our analysis of 40 field pennycress samples in two high- and two low-elevation populations detected 1,256,971 high-quality single nucleotide polymorphisms. Using three complementary selection tests, we detected 130 candidate naturally selected genes in the Qinghai-Tibet Plateau (QTP) populations, some of which are involved in DNA repair and the ubiquitin system and potential candidates involved in high-altitude adaptation. Notably, we detected a single base mutation causing loss-of-function of the FLOWERING LOCUS C protein, responsible for the transition to early flowering in high-elevation populations. Conclusions Our results provide a genome-wide perspective of how plants adapt to distinct environmental conditions across extreme elevation differences and the potential for further follow-up research with extensive data from additional populations and species.


2002 ◽  
Vol 82 (4) ◽  
pp. 803-823 ◽  
Author(s):  
S. I. Warwick ◽  
A. Francis ◽  
D. J. Susko

An updated review of biological information is provided for Thlaspi arvense. Native to Eurasia, the species is naturalized and widely spread in temperate regions of the northern hemisphere, including all of Canada's provinces and territories, and has recently spread to temperate regions in the southern hemisphere. It is an annual pioneer of disturbed soils and is an important weed of grain, oilseed, and forage crops in Canada, particularly in the prairies. High levels of erucic acid and glucosinolates can contaminate canola. When present in hay or other fodder, its seeds or leaves can be toxic to animals, as well as contaminate milk and meat with unpleasant flavors. It can serve as a host for insect, nematode, fungal and viral pests of canola and mustard crops. A persistent seed bank, high fecundity, and the growth habit of a hardy winter annual with early- (EF) and late-flowering (LF) strains, all contribute to its ability to compete with crops. Effective herbicides include the sulfonylureas, chlorsulfuron and ethametsulphuron, MCPA, tribenuronmethyl, phenocyacetic acid, flurtamone, 2,4-D, 2,4-D + dicamba, and 2,4-D + picloram. A resistant biotype to Group 2 herbicides, which inhibit acetolactate synthase (ALS), has been found at two to five sites in Alberta in 2001. The potential of T. arvense as an industrial oilseed crop is being investigated. Key words: Stinkweed, Thlaspi arvense, weed biology, field pennycress, fanweed, oilseed potential


1998 ◽  
Vol 3 (5) ◽  
pp. 8-10
Author(s):  
Robert L. Knobler ◽  
Charles N. Brooks ◽  
Leon H. Ensalada ◽  
James B. Talmage ◽  
Christopher R. Brigham

Abstract The author of the two-part article about evaluating reflex sympathetic dystrophy (RSD) responds to criticisms that a percentage impairment score may not adequately reflect the disability of an individual with RSD. The author highlights the importance of recognizing the difference between impairment and disability in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides): impairment is the loss, loss of use, or derangement of any body part, system, or function; disability is a decrease in or the loss or absence of the capacity to meet personal, social, or occupational demands or to meet statutory or regulatory requirements because of an impairment. The disparity between impairment and disability can be encountered in diverse clinical scenarios. For example, a person's ability to resume occupational activities following a major cardiac event depends on medical, social, and psychological factors, but nonmedical factors appear to present the greatest impediment and many persons do not resume work despite significant improvements in functional capacity. A key requirement according to the AMA Guides is objective documentation, and the author agrees that when physicians consider the disability evaluation of people, more issues than those relating to the percentage loss of function should be considered. More study of the relationships among impairment, disability, and quality of life in patients with RSD are required.


2019 ◽  
Vol 10 (1) ◽  
pp. 23-37
Author(s):  
Natalie Binczek

Der deutsche Barockdichter Georg Philipp Harsdörffer skizziert eine Theorie der Emblematik, die vor allem dessen Anwendungsvielfalt hervorhebt. Er hebt dabei besonders den Unterschied zwischen buchinterner und buchexterner Verwendung auf, indem er sich nicht nur für die Aufnahme der Embleme in Büchern, sondern auch auf Geschirr und Tapeten ausspricht. Der Beitrag liest Harsdörffers extensive Überlegungen nicht nur als Beiträge zur Theorie und Geschichte der Embleme als ›Sinn-Bilder‹, sondern auch als Beitrag zur Designgeschichte. German Baroque poet Georg Philipp Harsdörffer delineates a theory of emblematics that clearly sets itself apart from other contemporary theories, especially by its versatility. In particular, the author negates the difference between internal and external usage of emblems in books not only by promoting the incorporation of emblems into printed works but also by supporting their depiction on dishes and tapestries. This article strives to read Harsdörffer’s extensive thoughts on the matter of emblems not simply as another work on the theory and history of emblematics but rather as a contribution to design history as well


Author(s):  
Simon Kirchin

This chapter introduces the distinction between thin and thick concepts and then performs a number of functions. First, two major accounts of thick concepts—separationism and nonseparationism—are introduced and, in doing so, a novel account of evaluation is indicated. Second, each chapter is outlined as is the general methodology, followed, third, by a brief history of the discussion of thick concepts, referencing Philippa Foot, Hilary Putnam, Gilbert Ryle, and Bernard Williams among others. Fourth, a number of relevant contrasts are introduced, such as the fact–value distinction and the difference between concepts, properties, and terms. Lastly, some interesting and relevant questions are raised that, unfortunately, have to be left aside.


2002 ◽  
Vol 62 (1) ◽  
pp. 268-269
Author(s):  
Larry Neal

Economic historians usually have to explain to their economist colleagues the difference between economic history, which focuses on facts, and history of economic thought, which focuses on ideas. Our colleagues in finance departments, typically fascinated by episodes in financial history treated by economic historians, are bound to be disappointed in the lack of attention given to the development of ideas in finance by historians of economic thought. Geoffrey Poitras, a professor of finance at Simon Fraser University, makes a valiant effort to remedy these oversights in his collection of vignettes that highlight the sophistication of financial instruments and analysts of financial markets well before the time of Adam Smith. Starting in 1478 with the publication of the Treviso Arithmetic, a typical textbook of commercial arithmetic for Italian merchants, and ending with brief snippets from the Wealth of Nations, Poitras treats the reader to a fascinating potpourri of excerpts from various manuals, brief biographies of pioneers in financial analysis, and historical discursions on foreign-exchange and stock markets.


2021 ◽  
Vol 183 (3) ◽  
Author(s):  
Mario Ayala ◽  
Gioia Carinci ◽  
Frank Redig

AbstractWe study the symmetric inclusion process (SIP) in the condensation regime. We obtain an explicit scaling for the variance of the density field in this regime, when initially started from a homogeneous product measure. This provides relevant new information on the coarsening dynamics of condensing interacting particle systems on the infinite lattice. We obtain our result by proving convergence to sticky Brownian motion for the difference of positions of two SIP particles in the sense of Mosco convergence of Dirichlet forms. Our approach implies the convergence of the probabilities of two SIP particles to be together at time t. This, combined with self-duality, allows us to obtain the explicit scaling for the variance of the fluctuation field.


2021 ◽  
pp. 016224392110323
Author(s):  
Kristina Popova

The article addresses the production of reproducibility as a topic that has become acutely relevant in the recent discussions on the replication crisis in science. It brings the ethnomethodological stance on reproducibility into the discussions, claiming that reproducibility is necessarily produced locally, on the shop floor, with methodological guidelines serving as references to already established practices rather than their origins. The article refers to this argument empirically, analyzing how a group of novice neuroscientists performs a series of measurements in a transcranial magnetic stimulation experiment. Based on ethnography and video analysis, the article traces a history of the local measurement procedure invented by the researchers in order to overcome the experimental uncertainty. The article aims to demonstrate (1) how reproducibility of the local procedure is achieved in the shop floor work of the practitioners and (2) how the procedure becomes normalized and questioned as incorrect in the course of experimental practice. It concludes that the difference between guidelines and practical actions is not problematic per se; what may be problematic is that researchers can be engaged in different working projects described by the same instruction.


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