Asian rice is one of the world's most widely cultivated crops. Large-scale resequencing analyses have been undertaken to explore the domestication and de-domestication genomic history of Asian rice, ...but the evolution of rice is still under debate.
Here, we construct a syntelog-based rice pan-genome by integrating and merging 74 high-accuracy genomes based on long-read sequencing, encompassing all ecotypes and taxa of Oryza sativa and Oryza rufipogon. Analyses of syntelog groups illustrate subspecies divergence in gene presence-and-absence and haplotype composition and identify massive genomic regions putatively introgressed from ancient Geng/japonica to ancient Xian/indica or its wild ancestor, including almost all well-known domestication genes and a 4.5-Mbp centromere-spanning block, supporting a single domestication event in main rice subspecies. Genomic comparisons between weedy and cultivated rice highlight the contribution from wild introgression to the emergence of de-domestication syndromes in weedy rice.
This work highlights the significance of inter-taxa introgression in shaping diversification and divergence in rice evolution and provides an exploratory attempt by utilizing the advantages of pan-genomes in evolutionary studies.
Rye (Secale cereale) is an important crop with multiple uses and a valuable genetic resource for wheat breeding. However, due to its complex genome and outcrossing nature, the origin of cultivated ...rye remains elusive. The geneticist N.I. Vavilov proposed that cultivated rye had been domesticated from weedy rye, rather than directly from wild species like other crops. Unraveling the domestication history of rye will extend our understanding of crop evolution and upend our inherent understanding of agricultural weeds. To this end, in this study we generated the 8.5 Tb of whole-genome resequencing data from 116 worldwide accessions of wild, weedy, and cultivated rye, and demonstrated that cultivated rye was domesticated directly from weedy relatives with a similar but enhanced genomic selection by humans. We found that a repertoire of genes that experienced artificial selection is associated with important agronomic traits, including shattering, grain yield, and disease resistance. Furthermore, we identified a composite introgression in cultivated rye from the wild perennial Secale strictum and detected a 2-Mb introgressed fragment containing a candidate ammonium transporter gene with potential effect on the grain yield and plant growth of rye. Taken together, our findings unravel the domestication history of cultivated rye, suggest that interspecific introgression serves as one of the likely causes of obscure species taxonomy of the genus Secale, and provide an important resource for future rye and wheat breeding.
This study provides insight into genetic underpinning of the domestication of rye, a secondary domesticate (Vavilovian hypothesis) directly from weedy rye, based on genome resequencing data of 116 Secale accessions. A repertoire of domestication genes and a 2-Mb introgressed fragment from Secale strictum associated with important traits were identified, providing an important resource for future rye and wheat breeding.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As a noxious weed, weedy rice (Oryza sativa f. spontanea Roshev. 1931) has threatened global food security and sustainable crop production. On the other hand, weedy rice has a strong tolerance for ...abiotic stresses and the potential to provide rich resources for rice genetic improvement. Thus, for a more comprehensive understanding of its speciation, we sequenced and assembled the first complete chloroplast genome of Oryza sativa f. spontanea (japonica type). The complete chloroplast genome was 134,555 bp in length and encoded 133 genes, including 83 protein-coding genes, 42 tRNA genes and 8 rRNA genes. Phylogenetic analysis revealed that the indica-japonica differentiation of weedy rice was closely related to cultivated rice, and Oryza sativa f. spontanea (japonica type) was genetically more closely clustered with cultivated rice O. sativa (japonica type) than O. nivara or other wild rice.
The emergence of weedy rice (Oryza sativa f. spontanea) has been considered as a serious global agricultural problem in recent decades. To better understand its speciation, here we assembled the ...complete chloroplast genome of O. sativa f. spontanea with the length of 134,502 bp. The assembly contains a large single-copy (LSC, 80,549 bp), a small single-copy (SSC, 12,347 bp) and a pair of inverted repeats (IRa and IRb, 20,803 bp each). A total of 132 unique genes were annotated, including 82 protein-coding genes, 42 tRNA genes and eight rRNA genes. Phylogenetic analysis showed that O. sativa f. spontanea (indica type) appears closely related to cultivated indica rice rather than wild rice, supporting the hypothesis that weedy rice originated from cultivated rice.
Since nanozymes were proposed, their applications have become more and more extensive. As a research hotspot in recent years, MoS2 also shows many enzyme-like properties. However, as a novel ...peroxidase, MoS2 has the disadvantage of a low maximum reaction rate. In this study, the MoS2/PDA@Cu nanozyme was synthesized by a wet chemical method. The modification of PDA on the surface of MoS2 achieved the uniform growth of small-sized Cu Nps. The obtained MoS2/PDA@Cu nanozyme displayed excellent peroxidase-like activity and antibacterial properties. The minimum inhibitory concentration (MIC) of the MoS2/PDA@Cu nanozyme against S. aureus reached 25 μg mL−1. Furthermore, it showed a more pronounced inhibitory effect on bacterial growth with the addition of H2O2. The maximum reaction rate (Vmax) of the MoS2/PDA@Cu nanozyme is 29.33 × 10−8 M s−1, which is significantly higher as compared to that of HRP. It also exhibited excellent biocompatibility, hemocompatibility and potential anticancer properties. When the concentration of the nanozyme was 160 μg mL−1, the viabilities of 4T1 cells and Hep G2 cells were 45.07% and 32.35%, respectively. This work indicates that surface regulation and electronic transmission control are good strategies for improving peroxidase-like activity.
Since nanozymes were proposed, their applications have become more and more extensive. As a research hotspot in recent years, MoS
2
also shows many enzyme-like properties. However, as a novel ...peroxidase, MoS
2
has the disadvantage of a low maximum reaction rate. In this study, the MoS
2
/PDA@Cu nanozyme was synthesized by a wet chemical method. The modification of PDA on the surface of MoS
2
achieved the uniform growth of small-sized Cu Nps. The obtained MoS
2
/PDA@Cu nanozyme displayed excellent peroxidase-like activity and antibacterial properties. The minimum inhibitory concentration (MIC) of the MoS
2
/PDA@Cu nanozyme against
S. aureus
reached 25 μg mL
−1
. Furthermore, it showed a more pronounced inhibitory effect on bacterial growth with the addition of H
2
O
2
. The maximum reaction rate (
V
max
) of the MoS
2
/PDA@Cu nanozyme is 29.33 × 10
−8
M s
−1
, which is significantly higher as compared to that of HRP. It also exhibited excellent biocompatibility, hemocompatibility and potential anticancer properties. When the concentration of the nanozyme was 160 μg mL
−1
, the viabilities of 4T1 cells and Hep G2 cells were 45.07% and 32.35%, respectively. This work indicates that surface regulation and electronic transmission control are good strategies for improving peroxidase-like activity.
In this study, the obtained MoS
2
/PDA@Cu nanozyme, which utilizes PDA as an electron transport channel between MoS
2
and Cu Nps and growth site for smaller-sized Cu Nps, shows excellent peroxidase-like activity and antibacterial properties.
Since nanozymes were proposed, their applications have become more and more extensive. As a research hotspot in recent years, MoS
also shows many enzyme-like properties. However, as a novel ...peroxidase, MoS
has the disadvantage of a low maximum reaction rate. In this study, the MoS
/PDA@Cu nanozyme was synthesized by a wet chemical method. The modification of PDA on the surface of MoS
achieved the uniform growth of small-sized Cu Nps. The obtained MoS
/PDA@Cu nanozyme displayed excellent peroxidase-like activity and antibacterial properties. The minimum inhibitory concentration (MIC) of the MoS
/PDA@Cu nanozyme against
reached 25 μg mL
. Furthermore, it showed a more pronounced inhibitory effect on bacterial growth with the addition of H
O
. The maximum reaction rate (
) of the MoS
/PDA@Cu nanozyme is 29.33 × 10
M s
, which is significantly higher as compared to that of HRP. It also exhibited excellent biocompatibility, hemocompatibility and potential anticancer properties. When the concentration of the nanozyme was 160 μg mL
, the viabilities of 4T1 cells and Hep G2 cells were 45.07% and 32.35%, respectively. This work indicates that surface regulation and electronic transmission control are good strategies for improving peroxidase-like activity.
As one of the great survivors of the plant kingdom, barnyard grasses (Echinochloa spp.) are the most noxious and common weeds in paddy ecosystems. Meanwhile, at least two Echinochloa species have ...been domesticated and cultivated as millets. In order to better understand the genomic forces driving the evolution of Echinochloa species toward weed and crop characteristics, we assemble genomes of three Echinochloa species (allohexaploid E. crus-galli and E. colona, and allotetraploid E. oryzicola) and re-sequence 737 accessions of barnyard grasses and millets from 16 rice-producing countries. Phylogenomic and comparative genomic analyses reveal the complex and reticulate evolution in the speciation of Echinochloa polyploids and provide evidence of constrained disease-related gene copy numbers in Echinochloa. A population-level investigation uncovers deep population differentiation for local adaptation, multiple target-site herbicide resistance mutations of barnyard grasses, and limited domestication of barnyard millets. Our results provide genomic insights into the dual roles of Echinochloa species as weeds and crops as well as essential resources for studying plant polyploidization, adaptation, precision weed control and millet improvements.
Abstract
Efficient and robust platinum-carbon electrocatalysts are of great significance for the long-term service of high-performance fuel cells. Here, we report a Pt alloy integrated in a ...cobalt-nitrogen-nanocarbon matrix by a multiscale design principle for efficient oxygen reduction reaction. This Pt integrated catalyst demonstrates an increased mass activity, 11.7 times higher than that of commercial Pt catalyst, and retains a stability of 98.7% after 30,000 potential cycles. Additionally, this integrated catalyst delivers a current density of 1.50 A cm
−2
at 0.6 V in the hydrogen-air fuel cell and achieves a power density of 980 mW cm
−2
. Comprehensive investigations demonstrate that the synergistic contribution of components and structure in the platinum-carbon integrated catalyst is responsible for the high-efficiency ORR in fuel cells.
Abstract
Non-noble transition metal oxides are abundant in nature. However, they are widely regarded as catalytically inert for hydrogen evolution reaction (HER) due to their scarce active electronic ...states near the Fermi-level. How to largely improve the HER activity of these kinds of materials remains a great challenge. Herein, as a proof-of-concept, we design a non-solvent strategy to achieve phosphate substitution and the subsequent crystal phase stabilization of metastable β-NiMoO
4
. Phosphate substitution is proved to be imperative for the stabilization and activation of β-NiMoO
4
, which can efficiently generate the active electronic states and promote the intrinsic HER activity. As a result, phosphate substituted β-NiMoO
4
exhibits the optimal hydrogen adsorption free energy (−0.046 eV) and ultralow overpotential of −23 mV at 10 mA cm
−2
in 1 M KOH for HER. Especially, it maintains long-term stability for 200 h at the large current density of 1000 mA cm
−2
with an overpotential of only −210 mV. This work provides a route for activating transition metal oxides for HER by stabilizing the metastable phase with abundant active electronic states.
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