Summary
Seed weight is one of the most important agronomic traits in soybean for yield improvement and food production. Several quantitative trait loci (QTLs) associated with the trait have been ...identified in soybean. However, the genes underlying the QTLs and their functions remain largely unknown.
Using forward genetic methods and CRISPR/Cas9 gene editing, we identified and characterized the role of GmKIX8‐1 in the control of organ size in soybean.
GmKIX8‐1 belongs to a family of KIX domain‐containing proteins that negatively regulate cell proliferation in plants. Consistent with this predicted function, we found that loss‐of‐function GmKIX8‐1 mutants showed a significant increase in the size of aerial plant organs, such as seeds and leaves. Likewise, the increase in organ size is due to increased cell proliferation, rather than cell expansion, and increased expression of CYCLIN D3;1‐10.
Lastly, molecular analysis of soybean germplasms harboring the qSw17‐1 QTL for the big‐seeded phenotype indicated that reduced expression of GmKIX8‐1 is the genetic basis of the qSw17‐1 phenotype.
Summary
Ear length (EL), which is controlled by quantitative trait loci (QTLs), is an important component of grain yield and as such is a key target trait in maize breeding. However, very few EL QTLs ...have been cloned, and their molecular mechanisms are largely unknown.
Here, using a genome wide association study (GWAS), we identified a QTL, YIGE1, which encodes an unknown protein that regulates EL by affecting pistillate floret number. Overexpression of YIGE1 increased female inflorescence meristem (IM) size, increased EL and kernel number per row (KNPR), and thus enhanced grain yield. By contrast, CRISPR/Cas9 knockout and Mutator insertion mutant lines of YIGE1 displayed decreased IM size and EL.
A single‐nucleotide polymorphism (SNP) located in the regulatory region of YIGE1 had a large effect on its promoter strength, which positively affected EL by increasing gene expression. Further analysis shows that YIGE1 may be involved in sugar and auxin signal pathways to regulate maize ear development, thus affecting IM activity and floret production in maize inflorescence morphogenesis.
These findings provide new insights into ear development and will ultimately facilitate maize molecular breeding.
See also the Commentary on this article by Cowling & Kelley, 234: 337–339.
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To facilitate the solid-phase purification of synthetic DNA sequences, a riboside phosphoramidite, carrying a 5-O-capture linker and a 2-O-silyl ether protecting group, is ...incorporated into a DNA sequence during its last solid-phase synthesis cycle. After deprotection and release of the DNA sequence from the synthesis support, the sequence is then covalently linked to a capture support to enable the removal of shorter unbound DNA sequences by simply washing these off the support. The solid-phase purified DNA sequence is then released from the capture support, through an innovative intramolecular cyclodeesterification of its terminal riboside ethyl phosphate triester entity and is isolated in a yield of 94% while displaying an exquisite purity of 97%.
Type specimens are permanently preserved biological specimens that fix the usage of species names. This method became widespread from 1935 onwards and is now obligatory. We used DNA sequencing of ...types and more recent collections of wild and cultivated melons to reconstruct the evolutionary history of the genus Citrullus and the correct names for its species. We discovered that the type specimen of the name Citrullus lanatus, prepared by a Linnaean collector in South Africa in 1773, is not the species now thought of as watermelon. Instead, it is a representative of another species that is sister to C. ecirrhosus, a tendril‐less South African endemic. The closest relative of the watermelon instead is a West African species. Our nuclear and plastid data furthermore reveal that there are seven species of Citrullus, not four as assumed. Our study implies that sweet watermelon originates from West, not southern Africa as previously believed, and that the South African citron melon has been independently domesticated. These findings affect and explain numerous studies on the origin of these two crops that led to contradictory results because of the erroneous merging of several distinct species.
The nonrandom distribution of meiotic recombination influences patterns of inheritance and genome evolution, but chromosomal features governing this distribution are poorly understood. Formation of ...the DNA double-strand breaks (DSBs) that initiate recombination results in the accumulation of Spo11 protein covalently bound to small DNA fragments. By sequencing these fragments, we uncover a genome-wide DSB map of unprecedented resolution and sensitivity. We use this map to explore how DSB distribution is influenced by large-scale chromosome structures, chromatin, transcription factors, and local sequence composition. Our analysis offers mechanistic insight into DSB formation and early processing steps, supporting the view that the recombination terrain is molded by combinatorial and hierarchical interaction of factors that work on widely different size scales. This map illuminates the occurrence of DSBs in repetitive DNA elements, repair of which can lead to chromosomal rearrangements. We also discuss implications for evolutionary dynamics of recombination hot spots.
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► High-resolution view of meiotic DNA breaks from deep sequencing of Spo11-bound oligos ► Landscape of dsDNA breaks reflects large- and small-scale chromosome features ► Hot spots are just one level of spatial organization of meiotic recombination ► dsDNA breaks occur frequently in repetitive DNA, a risk for chromosome rearrangement
Pleosporales Zhang, Ying; Crous, Pedro W.; Schoch, Conrad L. ...
Fungal diversity,
03/2012, Letnik:
53, Številka:
1
Journal Article
Recenzirano
Odprti dostop
One hundred and five generic types of
Pleosporales
are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general ...conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of
Pleosporales
are treated.
Phaeotrichaceae
as well as
Kriegeriella
,
Zeuctomorpha
and
Muroia
are excluded from
Pleosporales
. Based on the multigene phylogenetic analysis, the suborder
Massarineae
is emended to accommodate five families, viz.
Lentitheciaceae
,
Massarinaceae
,
Montagnulaceae
,
Morosphaeriaceae
and
Trematosphaeriaceae
.
Soybean (Glycine max) is a major contributor to the world oilseed production. Its seed oil content has been increased through soybean domestication and improvement. However, the genes underlying the ...selection are largely unknown.
The present contribution analyzed the expression patterns of genes in the seed oil quantitative trait loci with strong selective sweep signals, then used association, functional study and population genetics to reveal a sucrose efflux transporter gene, GmSWEET39, controlling soybean seed oil content and under selection.
GmSWEET39 is highly expressed in soybean seeds and encodes a plasma membrane-localized protein. Its expression level is positively correlated with soybean seed oil content. The variation in its promoter and coding sequence leads to different natural alleles of this gene. The GmSWEET39 allelic effects on total oil content were confirmed in the seeds of soybean recombinant inbred lines, transgenic Arabidopsis, and transgenic soybean hairy roots. The frequencies of its superior alleles increased from wild soybean to cultivated soybean, and are much higher in released soybean cultivars.
The findings herein suggest that the sequence variation in GmSWEET39 affects its relative expression and oil content in soybean seeds, and GmSWEET39 has been selected to increase seed oil content during soybean domestication and improvement.
We study the adversarial torn-paper channel . This problem is motivated by applications in DNA data storage where the DNA strands that carry information may break into smaller pieces which are ...received out of order. Our model extends the previously researched probabilistic setting to the worst-case. We develop code constructions for any parameters of the channel for which non-vanishing asymptotic rate is possible and show our constructions achieve asymptotically optimal rate while allowing for efficient encoding and decoding. Finally, we extend our results to related settings included multi-strand storage, presence of substitution errors, or incomplete coverage.
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•Numerically, taxonomic research sensu lato dominates publications on fish parasites.•Discovery and genetic characterisation of new parasites are geographically biased.•Local research ...efforts aimed at parasite discovery are inconsistent over time.•The quality of taxonomic descriptions has improved unequally among helminth taxa.•Although in a good state, fish parasite taxonomy faces a few challenges ahead.
Efforts to find and characterise new parasite species in fish hosts are crucial not just to complete our inventory of Earth’s biodiversity, but also to monitor and mitigate disease threats in fisheries and aquaculture in the face of global climate change. Here, we review recent quantitative assessments of research efforts into fish parasite discovery and taxonomy. We address broad questions including: Are efforts aimed at finding new parasite species targeted at geographical hotspots of fish biodiversity, where there should be more parasite species to be found? Is the application of molecular tools to study parasite genetic diversity deployed strategically across regions of the world, or focused disproportionately on certain areas? How well coordinated is the search for new parasite species of fish among workers specialising on different higher helminth taxa? Are parasite discovery efforts in any geographical area consistent over time, or subject to idiosyncrasies due to the waxing and waning of highly prolific research careers? Is the quality of taxonomic descriptions of new species improving over time, with the incorporation of new tools to characterise species? Are taxonomic descriptions moving away from a focus on the adult stage only toward attempts to characterise the full life cycle of newly-discovered helminth species? By using empirical evidence to answer these questions, we assess the current state of research into fish parasite discovery and taxonomy. We also explore the far-reaching implications of recent research on parasite microbiomes for parasite taxonomy. We end with recommendations aimed at maximising the knowledge gained per fish sacrificed, and per dollar and time invested into research on fish parasite biodiversity.
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