Complex rhizoremediation is the main mechanism of phytoremediation in organic-contaminated soil. Low molecular weight organic acids (LMWOAs) in root exudates have been shown to increase the ...bioavailability of contaminants and are essential for promoting the dissipation of contaminants. The effects of root exudates on the dissipation of organophosphate esters (OPEs) in soil are unclear. Consequently, we studied the combined effects of root exudates, soil enzymes and microorganisms on OPEs (tri (1-chloro-2-propyl) phosphate (TCPP) and triphenyl phosphate (TPP)) dissipation through pot experiments. Oxalic acid (OA) was confirmed to be the main component of LMWOAs in root exudates of ryegrass. The existence of OA increased the dissipation rate of OPEs by 6.04%–25.50%. Catalase and dehydrogenase activities were firstly activated and then inhibited in soil. While, urease activity was activated and alkaline phosphatase activity was inhibited during the exposure period. More bacteria enrichment (e.g., Sphingomonas, Pseudomonas, Flavisolibacter, Pontibacter, Methylophilus and Massilia) improved the biodegradation of OPEs. In addition, the transformation paths of OPEs hydrolysis and methylation under the action of root exudates were observed. This study provided theoretical insights into reducing the pollution risk of OPEs in the soil.
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•Oxalic acid was the main component of ryegrass root exudates.•OPEs stress enhanced the secretion of oxalic acid.•The root exudates of ryegrass promoted the degradation of OPEs in soil.•Microbial communities were significantly affected by root exudates.
Tetrabromobisphenol A (TBBPA) and its derivatives are widely used as brominated flame retardants. Because of their high production and wide environment distribution, TBBPA derivatives have increased ...considerable concern. Previous studies have primarily focused on TBBPA, with limited information available on its derivative. In this study, we investigated the uptake, biotransformation and physiological response of two derivatives, Tetrabromobisphenol A bis(allyl ether) (TBBPA BAE) and Tetrabromobisphenol A bis(2,3-dibromopropylether) (TBBPA BDBPE), in Helianthus annus (H. annus) through a short-term hydroponic assay. The results revealed that H. annus could absorb TBBPA BAE and TBBPA BDBPE from solution, with removal efficiencies of 98.33 ± 0.5% and 98.49 ± 1.56% after 10 days, respectively, which followed first-order kinetics. TBBPA BAE was absorbed, translocated and accumulated while TBBPA BDBPE couldn't be translocated upward due to its high hydrophobicity and low solubility. The concentrations of TBBPA derivatives in plants peaked within 72 h, and then decreased. We identified twelve metabolites resulting from ether bond breakage, debromination, and hydroxylation in H. annus. The high-level TBBPA BAE suppressed the growth and increased malondialdehyde (MDA) content of H. annus, while TBBPA BDBPE didn't pose a negative effect on H. annus. TBBPA BAE and TBBPA BDBPE increased the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), with higher levels of these enzymes activity found in high concentration treatments. Contrastingly, TBBPA BAE exhibited higher toxicity than TBBPA BDBPE, as indicated by greater antioxidant enzyme activity. The findings of this study develop better understanding of biotransformation mechanisms of TBBPA derivatives in plants, contributing to the assessment of the environmental and human health impacts of these contaminants.
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•H. annus could uptake TBBPA derivatives, but translocation of TBBPA BDBPE was limited.•TBBPA derivatives' ether breakage, debromination and hydroxylation in H. annus.•High-level of TBBPA BAE inhibited the growth and development of H. annus.•TBBPA derivatives induced SOD, POD and CAT activities in H. annus.•TBBPA BAE has higher toxicity than TBBPA BDBPE.
Biotransformation is a major dissipation process of tetrabromobisphenol A and its derivatives (TBBPAs) in soil. The biotransformation and ultimate environmental fate of TBBPAs have been widely ...studied, yet the effect of root exudates (especially low-molecular weight organic acids (LMWOAs)) on the fate of TBBPAs is poorly documented. Herein, the biotransformation behavior and mechanism of TBBPAs in bacteriome driven by LMWOAs were comprehensively investigated. Tartaric acid (TTA) was found to be the main component of LMWOAs in root exudates of Helianthus annus in the presence of TBBPAs, and was identified to play a key role in driving shaping bacteriome. TTA promoted shift of the dominant genus in soil bacteriome from Saccharibacteria_genera_incertae_sedis to Gemmatimonas, with a noteworthy increase of 24.90–34.65% in relative abundance of Gemmatimonas. A total of 28 conversion products were successfully identified, and β-scission was the principal biotransformation pathway for TBBPAs. TTA facilitated the emergence of novel conversion products, including 2,4-dibromophenol, 3,5-dibromo-4-hydroxyacetophenone, para-hydroxyacetophenone, and tribromobisphenol A. These products were formed via oxidative skeletal cleavage and debromination pathways. Additionally, bisphenol A was observed during the conversion of derivatives. This study provides a comprehensive understanding about biotransformation of TBBPAs driven by TTA in soil bacteriome, offering new insights into LMWOAs-driven biotransformation mechanisms.
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•Biotransformation of TBBPAs in soil mediated by root exudates was first investigated.•A total of 28 biotransformation products were successfully identified.•Tartaric acid promoted the debromination and oxidative skeletal cleavage pathways.•Some single-ring products were first identified under mediation of tartaric acid.
High‐pressure resistant and multidirectional compressible materials enable various applications but are often hindered by structure‐derived collapse and weak elasticity. Here, a super‐robust graphene ...foam with ladder shape microstructure capable of withstanding high pressure is presented. The multioriented ladder arrays architecture of the foam, consisting of thousands of identically sized square spaces, endow it with a great deal of elastic units. It can easily bear an iterative and multidirectional pressure of 44.5 MPa produced by a sharp blade, and may completely recover to its initial state by a load of 180 000 times their own weight even under 95% strain. More importantly, the foam can also maintain structural integrity after experiencing a pressure of 2.8 GPa through siphoning. Computational modeling of the “buckling of shells” mechanism reveals the unique ladder‐shaped graphene foam contributes to the superior cut resistance and good resilience. Based on this finding, it can be widely used in cutting resistance sensors, monitoring of sea level, and the detection of oily contaminants in water delivery pipelines.
A super‐robust graphene foam with ladder‐shape microstructure‐derived outstanding mechanical properties including cutting resistance and high recovery is designed, based on which it can be applied in cutting resistance pressure sensors, monitoring sea level, and detecting oily contaminants in water transmission pipeline.
Phytoremediation mediated by microorganisms in the rhizosphere is a promising technology for the effective management of petroleum hydrocarbons-contaminated soil. However, it is essential to explore ...the dynamics of the micro-environment in the rhizosphere during phytoremediation process. A pot xperiment was conducted to investigate the ecological response of rhizospheric environmental of landscaping plant (Helianthus annus) to the petroleum hydrocarbon compounds (PHCs) contamination. The results showed that the species had a high ability to remove PHCs, and the removal of n-alkanes largely depended on symbiotic microorganisms in the root zone. The remediation efficiency of Helianthus could be regulated by rhizosphere microbes through the enhancement of nutrients and energy cycling, remodeling of the beneficial bacterial abundance, and improvement of enzyme activities. In addition, the ecological response of rhizosphere soil was closely related to the root exudation effect of plant and PHCs exposure. The present study provides information about the succession pattern and response of the microbial community of rhizosphere soil in the PHCs phytoremediation of Helianthus annus, and demonstrated the feasibility of Helianthus annus in the effective management of PHCs in contaminated soil.
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Summary
Uncovering the genetic basis of agronomic traits in wheat landraces is important for ensuring global food security via the development of improved varieties. Here, 723 wheat landraces from 10 ...Chinese agro‐ecological zones were evaluated for 23 agronomic traits in six environments. All accessions could be clustered into five subgroups based on phenotypic data via discriminant function analysis, which was highly consistent with genotypic classification. A genome‐wide association study was conducted for these traits using 52 303 DArT‐seq markers to identify marker‐trait associations and candidate genes. Using both the general linear model and the mixed linear model, 149 significant markers were identified for 21 agronomic traits based on best linear unbiased prediction values. Considering the linkage disequilibrium decay distance in this study, significant markers within 10 cM were combined as a quantitative trait locus (QTL), with a total of 29 QTL identified for 15 traits. Of these, five QTL for heading date, flag leaf width, peduncle length, and thousand kernel weight had been reported previously. Twenty‐five candidate genes associated with significant markers were identified. These included the known vernalization genes VRN‐B1 and vrn‐B3 and the photoperiod response genes Ppd and PRR. Overall, this study should be helpful in elucidating the underlying genetic mechanisms of complex agronomic traits and performing marker‐assisted selection in wheat.
Significance Statement
The genome‐wide associations study is a powerful method to identify marker‐trait associations and dissect the genetic architecture of complex agronomic traits in crops. Here, 723 wheat landraces from 10 agro‐ecological zones in China were evaluated for 23 agronomic traits in multi‐environments. With the use of 52 303 DArT‐seq markers, we identified 149 significant markers for 21 traits, as well as 25 candidate genes for 13 traits. These results could facilitate the utilization of wheat genetic resources in molecular breeding.
The progress of space science and technology has ushered in a new era for humanity's exploration of outer space. Recent studies have indicated that the aerospace special environment including ...microgravity and space radiation poses a significant risk to the health of astronauts, which involves multiple pathophysiological effects on the human body as well on tissues and organs. It has been an important research topic to study the molecular mechanism of body damage and further explore countermeasures against the physiological and pathological changes caused by the space environment. In this study, we used the rat model to study the biological effects of the tissue damage and related molecular pathway under either simulated microgravity or heavy ion radiation or combined stimulation. Our study disclosed that ureaplasma-sensitive amino oxidase (SSAO) upregulation is closely related to the systematic inflammatory response (IL-6, TNF-α) in rats under a simulated aerospace environment. In particular, the space environment leads to significant changes in the level of inflammatory genes in heart tissues, thus altering the expression and activity of SSAO and causing inflammatory responses. The detailed molecular mechanisms have been further validated in the genetic engineering cell line model. Overall, this work clearly shows the biological implication of SSAO upregulation in microgravity and radiation-mediated inflammatory response, providing a scientific basis or potential target for further in-depth investigation of the pathological damage and protection strategy under a space environment.
At present, it is widely believed that a 95-96% average nucleotide identity (ANI) value is equivalent to a 70% digital DNA-DNA hybridization (dDDH) value in the prokaryotic taxonomy. However, in the ...present study, comparative genome analysis of 29 pairs of
type strains revealed that a 70% dDDH value did not correspond to a 95-96% ANI based on the MuMmer ultra-rapid aligning tool (ANIm) but approximately corresponded to a 96.6% ANIm value in the genus
. Based on this corresponding relationship, phenotypic and chemotaxonomical characteristics, as well as phylogenetic analysis, an actinobacterial strain HUAS 11-8
isolated from the rhizosphere soil of
, was subjected to a polyphasic taxonomic characterization. Based on EzBioCloud alignment, it was found that strain HUAS11-8
had the 16S rRNA gene similarities of 99.78% with
JCM 32589
, 97.8% with
YIM 75904
, and < 97.8% sequence similarities to other
species. Phylogenetic analysis of 16S rRNA gene sequences and whole-genome sequences revealed that strain HUAS 11-8
was closely related to
JCM 32589
. ANIm and dDDH values between strains HUAS 11-8
and
JCM 32589
were 96.3 and 68.5%, respectively, lower than the 96.6 and 70% thresholds recommended for the delineation of a novel
species. Consequently, strain HUAS 11-8
should represent a novel
species, for which the name
sp. nov. (type strain HUAS 11-8
= MCCC 1K08337
= JCM 35980
) is proposed. Furthermore, based on comparative genomic analysis and rule 42 of the Prokaryotic Code, we propose that
is a later heterotypic synonym of
.
Key Message
A novel and major QTL for the effective tiller number was identified on chromosomal arm 1BL and validated in two genetic backgrounds
The effective tiller number (ETN) substantially ...influences plant architecture and the wheat yield improvement. In this study, we constructed a genetic map of the 2SY (20828/SY95-71) recombinant inbred line population based on the Wheat 55K array as well as the simple sequence repeat (SSR) and Kompetitive Allele Specific PCR (KASP) markers. A comparison between the genetic and physical maps indicated the marker positions were consistent in the two maps. Additionally, we identified seven tillering-related quantitative trait locus (QTLs), including
Qetn-sau-1B.1
, which is a major QTL localized to a 6.17-cM interval flanked by markers
AX-89635557
and
AX-111544678
on chromosome 1BL. The
Qetn-sau-1B.1
QTL was detected in eight environments and explained 12.12–55.71% of the phenotypic variance. Three genes associated with the ETN were detected in the physical interval of
Qetn-sau-1B.1
. We used a tightly linked KASP marker,
KASP-AX-110129912
, to further validate this QTL in two other populations with different genetic backgrounds. The results indicated that
Qetn-sau-1B.1
significantly increased the ETN by up to 23.5%. The results of this study will be useful for the precise mapping and cloning of
Qetn-sau-1B.1
.
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