Development of wheat-tetraploid Thinopyrum elongatum 4EL small fragment translocation lines with stripe rust resistance gene Yr4EL.

KEY MESSAGE: Two small fragment translocation lines (T4DS·4DL-4EL and T5AS·5AL-4EL) showed high resistance to stripe rust and resistance gene Yr4EL was localized to an about 35 Mb region at the end of chr arm 4EL. Stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici, is a devastating wheat disease worldwide. Deployment of disease resistance (R) genes in wheat cultivars is the most effective way to control the disease. Previously, the all-stage stripe rust R gene Yr4EL from tetraploid Thinopyrum elongatum was introduced into common wheat as 4E(4D) substitution and T4DS·4EL translocation lines. To further map and utilize Yr4EL, Chinese Spring (CS) mutant pairing homoeologous gene ph1b was used in crossing to induce recombination between chromosome (chr) 4EL and wheat chromosomes. Two small fragment translocation lines T4DS·4DL-4EL and T5AS·5AL-4EL with Yr4EL resistance were selected using molecular markers and confirmed by genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), and Wheat 660 K SNP array analyses. We mapped Yr4EL to an about 35 Mb region at the end of chr 4EL, corresponding to 577.76-612.97 Mb based on the diploid Th. elongatum reference genome. In addition, two competitive allele-specific PCR (KASP) markers co-segregating with Yr4EL were developed to facilitate molecular marker-assisted selection in breeding. The T4DS·4DL-4EL lines were crossed and backcrossed with wheat cultivars SM482 and CM42, and the resulting pre-breeding lines showed high stripe rust resistance and potential for wheat breeding with good agronomic traits. These lines represent new germplasm for wheat stripe rust resistance breeding, as well as providing a solid foundation for Yr4EL fine mapping and cloning.

Biorenewable and circular polyolefin thermoplastic elastomers.

Polymers capable of depolymerizing back to their own monomers offer a promising solution to address the challenges in polymer sustainability. Despite significant progress has been achieved in plastics circularity, chemical recycling of thermoplastic elastomers is relatively less concerned, largely because of their intrinsic complex multicomponents. This work creates a homopolymer-based platform towards chemically recyclable but tough thermoplastic elastomers. It is enabled by a semicrystalline polymer with high molecular weight but low crystallinity, which is prepared through ring-opening metathesis polymerization of a fully biobased cyclic olefin. By shifting the ring-chain equilibrium, quantitative conversions were achieved for both forward polymerization and reverse depolymerization. This simple circular, high-performance thermoplastic elastomer platform based on biomass highlights the importance of monomer design in addressing three challenges in sustainable polymers: the feedstock renewability, depolymerization selectivity, and performance trade-offs.

Soil application of FeCl3 and Fe2(SO4)3 reduced grain cadmium concentration in Polish wheat (Triticum polonicum L.).

BACKGROUND: Wheat is one of major sources of human cadmium (Cd) intake. Reducing the grain Cd concentrations in wheat is urgently required to ensure food security and human health. In this study, we performed a field experiment at Wenjiang experimental field of Sichuan Agricultural University (Chengdu, China) to reveal the effects of FeCl3 and Fe2(SO4)3 on reducing grain Cd concentrations in dwarf Polish wheat (Triticum polonicum L., 2n = 4x = 28, AABB). RESULTS: Soil application of FeCl3 and Fe2(SO4)3 (0.04 M Fe3+/m2) significantly reduced grain Cd concentration in DPW at maturity by 19.04% and 33.33%, respectively. They did not reduce Cd uptake or root-to-shoot Cd translocation, but increased Cd distribution in lower leaves, lower internodes, and glumes. Meanwhile, application of FeCl3 and Fe2(SO4)3 up-regulated the expression of TpNRAMP5, TpNRAMP2 and TpYSL15 in roots, and TpYSL15 and TpZIP3 in shoots; they also downregulated the expression of TpZIP1 and TpZIP3 in roots, and TpIRT1 and TpNRAMP5 in shoots. CONCLUSIONS: The reduction in grain Cd concentration caused by application of FeCl3 and Fe2(SO4)3 was resulted from changes in shoot Cd distribution via regulating the expression of some metal transporter genes. Overall, this study reports the physiological pathways of soil applied Fe fertilizer on grain Cd concentration in wheat, suggests a strategy for reducing grain Cd concentration by altering shoot Cd distribution.

A Biobased Vitrimer: Self-Healing, Shape Memory, and Recyclability Induced by Dynamic Covalent Bond Exchange.

Plant oil-based vitrimer is an innovative and sustainable polymer with wide-ranging potential applications in the field of advanced materials. However, its restricted application is caused by the poor mechanical properties and the need for catalysts during preparation. Using renewable cardanol as the raw material, epoxy cardanol glycidyl ether (ECGE) with an end epoxide group was obtained by the clicking reaction and epoxidation reaction. After the application of citric acid (CA), ECGE was successfully cured, resulting in the production of fully biobased ECGE-CA vitrimers. This material does not require a catalyst, possesses self-healing properties, and exhibits high mechanical strength. On account of the introduction of hydroxyl groups in citric acid, plenty of hydrogen bonds are formed, allowing the topological network rearrangement of the material in the absence of a catalyst. Recyclable adhesives and repairable materials, vitrimer polymers have good shape memory, self-healing, and recyclability since of their dynamic ester and hydroxyl bonds.

Assessing impact of elevated CO2 on heavy metal accumulation in crops: meta-analysis and implications for food security.

Human activities led to elevation in carbon dioxide (CO2) concentrations in atmosphere. While such increase per se may be beneficial for the growth of some crops, it comes with a caveat of affecting crop nutritional status. Here, we present a comprehensive analysis of changes in concentration of essential (Cu, Fe, Mn, Zn, Mo, Ni) and non-essential (Ba, Cd, Cr, Hg, Pb, and Sr) heavy metals in response to elevated CO2, drawing on a meta-analysis of 1216 paired observations. The major findings are as follows: (1) Elevated CO2 leads to reduced concentrations of Cu, Fe, Mn, and Zn in crops; (2) the extent of above reduction varies among plants species and is most pronounced in cereals and then in legumes and vegetables; (3) reduction in accumulation of non-essential (toxic) metals is less pronounced, potentially leading to an unfavorable essential/non-essential metal ratio in plants; (4) the above effects will come with significant implication to human health, exacerbating effects of the "hidden hunger" caused by the lack of Fe and Zn in the human diets. The paper also analyses the mechanistic basis of nutrient acquisition (both at physiological and molecular levels) and calls for the changes in the governmental policies to increase efforts of plant breeders to create genotypes with improved nutrient use efficiency for essential micronutrients while uncoupling their transport from non-essential (toxic) heavy metals.

Introgression of tetraploid Thinopyrum elongatum 6EL segments enhances the stripe rust resistance of adult wheat plants.

Preventing the widespread occurrence of stripe rust in wheat largely depends on the identification of new stripe rust resistance genes and the breeding of cultivars with durable resistance. In previous study, we reported 6E of wheat-tetraploid Thinopyrum elongatum 6E (6D) substitution line contains adult-stage stripe rust resistance genes. In this study, three novel wheat-tetraploid Th. elongatum translocation lines were generated from the offspring of a cross between common wheat and the 6E (6D) substitution line. Genomic in situ hybridization (GISH), fluorescence in situ hybridization chromosome painting (FISH painting), repetitive sequential FISH, and 55 K SNP analyses indicated that K227-48, K242-82, and K246-6 contained 42 chromosomes and were 6DL·6ES, 2DL·6EL, and 6DS·6EL translocation lines, respectively. The assessment of stripe rust resistance revealed that K227-48 was susceptible to a mixture of Pst races, whereas the 6EL lines K242-82 and K246-6 were highly resistance to stripe rust at the adult stage. Thus, this resistance was due to the chromosome arm 6EL of tetraploid Th. elongatum. The improved agronomic performance of 6DS·6EL translocation line may be a useful novel germplasm resource for wheat breeding programs. For the application of marker-assisted selection (MAS), 47 simple sequence repeat (SSR) markers were developed, showing specific amplification on the chromosome 6E using the whole-genome sequence of diploid Th. elongatum. The 6DS·6EL translocation line and SSR markers have the potential to be deploy for future stripe rust resistance wheat breeding program. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01493-6.

Chromosome-specific painting reveals the Y genome origin and chromosome rearrangements of the St genome in Triticeae.

Karyotypes provide key cytogenetic information on phylogenetic relationships and evolutionary origins in related plant species. The St genome of Pseudoroegneria contributes to 8 alloploid genera, representing over half of the species that are highly valuable for wheat (Triticum aestivum) breeding and for understanding Triticeae species evolution. However, St chromosome characterization is challenging due to limited cytogenetic markers and DNA information. We developed a complete set of St genome-specific chromosome painting probes for identification of the individual chromosomes 1St to 7St based on the genome sequences of Pseudoroegneria libanotica and wheat. We revealed the conservation of St chromosomes in St-containing species by chromosome painting, including Pseudoroegneria, Roegneria, Elymus, and Campeiostachys. Notably, the Y genome showed hybridization signals, albeit weaker than those of the St genome. The awnless species harboring the Y genome exhibited more intense hybridization signals compare to the awned species in Roegneria and Campeiostachys, yet weaker than the hybridization signals of the St genome in autotetraploid Pseudoroegneria strigosa. Although awnless species were morphologically more similar to each other, phenotypic divergence progressively increased from awnless to awned species. Our results indicate that the Y genome originated from the St genome and shed light on the possible origin of the Roegneria and Campeiostachys species, enhancing our understanding of St-genome-containing species evolution.

The mechanism and therapeutic potential of lncRNA MIR497HG/miR-16-5p axis in breast cancer.

BACKGROUND: Breast cancer has become a major public health problem in the current society, and its incidence rate ranks the first among Chinese female malignant tumors. This paper once again confirmed the efficacy of lncRNA in tumor regulation by introducing the mechanism of the diagnosis of breast cancer by the MIR497HG/miR-16-5p axis. METHODS: The abnormal expression of MIR497HG in breast cancer was determined by RT-qPCR method, and the correlation between MIR497HG expression and clinicopathological characteristics of breast cancer patients was analyzed via Chi-square test. To understand the diagnostic potential of MIR497HG in breast cancer by drawing the receiver operating characteristic curve (ROC). The overexpressed MIR497HG (pcDNA3.1-MIR497HG) was designed and constructed to explore the regulation of elevated MIR497HG on biological function of BT549 and Hs 578T cells through Transwell assays. Additionally, the luciferase gene reporter assay and Pearson analysis evaluated the targeting relationship of MIR497HG to miR-16-5p. RESULTS: MIR497HG was decreased in breast cancer and had high diagnostic function, while elevated MIR497HG inhibited the migration and invasion of BT549 and Hs 578T cells. In terms of functional mechanism, miR-16-5p was the target of MIR497HG, and MIR497HG reversely regulated the miR-16-5p. miR-16-5p mimic reversed the effects of upregulated MIR497HG on cell biological function. CONCLUSIONS: In general, MIR497HG was decreased in breast cancer, and the MIR497HG/miR-16-5p axis regulated breast cancer tumorigenesis, providing effective insights for the diagnosis of patients.

irAE-colitis induced by CTLA-4 and PD-1 blocking were ameliorated by TNF blocking and modulation of gut microbial.

Immune-related adverse events, particularly colitis (irAE-colitis), are significant impediments to the advancement of immune checkpoint therapy. To address this, blocking TNF-α and modulating gut microbiota are effective strategies. However, their precise roles in irAE-colitis pathogenesis and potential reciprocal relationship remain unclear. An irAE-colitis model was established to evaluate the toxicity of DICB and the efficacy of Infliximab, validated through a tumor irAE-colitis mice model. Co-administration of Infliximab with DICB mitigates colitis and enhances efficacy. Analysis of fecal samples from mice reveals altered gut microbiota composition and function induced by irAE-colitis, restored by Infliximab. Notably, Bacteriodes abundance is significantly higher in irAE-colitis. Disruption of arachidonic acid and tyrosine metabolism, and steroid hormone biosynthesis is evident. Mechanistically, a regenerative feedback loop involving DICB, TNF-α and gut microbiota underlies irAE-colitis pathogenesis. In conclusion, Infliximab shows therapeutic effects against DICB toxicity, highlighting the unforeseen roles of gut microbiota and TNF-α in irAE-colitis.

Identification and Characterization of LBD Gene Family in Pseudoroegneria libanotica Reveals Functions of PseLBD1 and PseLBD12 in Response to Abiotic Stress.

The lateral organ boundaries domain (LBD) plays a vital role as a transcriptional coactivator within plants, serving as an indispensable function in growth, development, and stress response. In a previous study, we found that the LBD genes of Pseudoroegneria libanotica (a maternal donor for three-quarter of perennial Triticeae species with good stress resistance, holds great significance in exploring its response mechanisms to abiotic stress for the Triticeae tribe) might be involved in responding to drought stress. Therefore, we further identified the LBD gene family in this study. A total of 29 PseLBDs were identified. Among them, 24 were categorized into subclass I, while 5 fell into subclass II. The identification of cis-acting elements reveals the extensive involvement of PseLBDs in various biological processes in P. libanotica. Collinearity analysis indicates that 86% of PseLBDs were single-copy genes and have undergone a single whole-genome duplication event. Transcriptomic differential expression analysis of PseLBDs under drought stress reveals that the most likely candidates for responding to abiotic stress were PseLBD1 and PseLBD12. They have been demonstrated to respond to drought, salt, heavy metal, and heat stress in yeast. Furthermore, it is plausible that functional divergence might have occurred among their orthologous genes in wheat. This study not only establishes a foundation for a deeper understanding of the biological roles of PseLBDs in P. libanotica but also unveils novel potential genes for enhancing the genetic background of crops within Triticeae crops, such as wheat.

Genetic factors of grain cadmium concentration in Polish wheat (Triticum polonicum L.).

Wheat (Triticum aestivum L.) is one of the most important crops worldwide and a major source of human cadmium (Cd) intake. Limiting grain Cd concentration (Gr_Cd_Conc) in wheat is necessary to ensure food safety. However, the genetic factors associated with Cd uptake, translocation and distribution and Gr_Cd_Conc in wheat are poorly understood. Here, we mapped quantitative trait loci (QTLs) for Gr_Cd_Conc and its related transport pathway using a recombinant inbred line (RIL) population derived from 2 Polish wheat varieties (RIL_DT; dwarf Polish wheat [DPW] and tall Polish wheat [TPW]). We identified 29 novel major QTLs for grain and tissue Cd concentration; 14 novel major QTLs for Cd uptake, translocation, and distribution; and 27 major QTLs for agronomic traits. We also analyzed the pleiotropy of these QTLs. Six novel QTLs (QGr_Cd_Conc-1A, QGr_Cd_Conc-3A, QGr_Cd_Conc-4B, QGr_Cd_Conc-5B, QGr_Cd_Conc-6A, and QGr_Cd_Conc-7A) for Gr_Cd_Conc explained 8.16% to 17.02% of the phenotypic variation. QGr_Cd_Conc-3A, QGr_Cd_Conc-6A, and QGr_Cd_Conc-7A pleiotropically regulated Cd transport; 3 other QTLs were organ-specific for Gr_Cd_Conc. We fine-mapped the locus of QGr_Cd_Conc-4B and identified the candidate gene as Cation/Ca exchanger 2 (TpCCX2-4B), which was differentially expressed in DPW and TPW. It encodes an endoplasmic reticulum membrane/plasma membrane-localized Cd efflux transporter in yeast. Overexpression of TpCCX2-4B reduced Gr_Cd_Conc in rice. The average Gr_Cd_Conc was significantly lower in TpCCX2-4BDPW genotypes than in TpCCX2-4BTPW genotypes of the RIL_DT population and 2 other natural populations, based on a Kompetitive allele-specific PCR marker derived from the different promoter sequences between TpCCX2-4BDPW and TpCCX2-4BTPW. Our study reveals the genetic mechanism of Cd accumulation in wheat and provides valuable resources for genetic improvement of low-Cd-accumulating wheat cultivars.

Lipidomics random forest algorithm of seminal plasma is a promising method for enhancing the diagnosis of necrozoospermia.

BACKGROUND: Despite the clear clinical diagnostic criteria for necrozoospermia in andrology, the fundamental mechanisms underlying it remain elusive. This study aims to profile the lipid composition in seminal plasma systematically and to ascertain the potential of lipid biomarkers in the accurate diagnosis of necrozoospermia. It also evaluates the efficacy of a lipidomics-based random forest algorithm model in identifying necrozoospermia. METHODS: Seminal plasma samples were collected from patients diagnosed with necrozoospermia (n = 28) and normozoospermia (n = 28). Liquid chromatography-mass spectrometry (LC-MS) was used to perform lipidomic analysis and identify the underlying biomarkers. A lipid functional enrichment analysis was conducted using the LION lipid ontology database. The top 100 differentially significant lipids were subjected to lipid biomarker examination through random forest machine learning model. RESULTS: Lipidomic analysis identified 46 lipid classes comprising 1267 lipid metabolites in seminal plasma. The top five enriched lipid functions as follows: fatty acid (FA) with ≤ 18 carbons, FA with 16-18 carbons, monounsaturated FA, FA with 18 carbons, and FA with 16 carbons. The top 100 differentially significant lipids were subjected to machine learning analysis and identified 20 feature lipids. The random forest model identified lipids with an area under the curve > 0.8, including LPE(20:4) and TG(4:0_14:1_16:0). CONCLUSIONS: LPE(20:4) and TG(4:0_14:1_16:0), were identified as differential lipids for necrozoospermia. Seminal plasma lipidomic analysis could provide valuable biochemical information for the diagnosis of necrozoospermia, and its combination with conventional sperm analysis may improve the accuracy and reliability of the diagnosis.

Unlocking the potential of phenolated kraft lignin as a versatile feed additive.

Lignin, a renewable natural antioxidant and bacteriostat, holds promise as a versatile, cost-effective feed additive. However, traditional industrial lignin faces limitations, including low reactivity, poor uniformity, and unstable properties, necessitating chemical modification. Complex modification methods pose economic and toxicity challenges, so this study adopted a relatively simple alkali-catalyzed phenolization approach, using phenol, catechol, and pyrogallol to modify kraft lignin, and characterized the resulting products using various techniques. Subsequently, their antioxidant, antibacterial, adsorption properties for heavy metal ions and mycotoxins, growth-promoting properties, and antiviral abilities were assessed. The phenolation process led to lignin depolymerization and a notable increase in phenolic hydroxyl content, particularly in pyrogallol-phenolated lignin (Py-L), rising from 3.08 to 4.68 mmol/g. These modified lignins exhibited enhanced antioxidant activity, with over 99 % inhibition against E. coli and S. aureus, and remarkable adsorption capacities for heavy metal ions and mycotoxins. Importantly, Py-L improved the growth performance of mice and reduced influenza mortality. Furthermore, density functional theory calculations elucidated the mechanism behind the enhanced antioxidant properties. This study presents a promising avenue for developing versatile feed additives to address challenges related to animal feed antioxidant supplementation, bacterial control, and growth promotion.

Expression and Significance of LINC02418 in Breast Cancer.

Purpose: The complicated pathogenesis and poor prognosis of breast cancer have become a major difficulty in medical research. This study aims to explore new lncRNA as prognostic markers for breast cancer and explore their roles and molecular mechanisms to lay a foundation for the treatment of cancer patients. Patients and Methods: The expression of LINC02418 and miR-766-5p in breast cancer tissues and cells was first identified using polymerase chain reaction, and Pearson was used to examine the correlation between the two. The cancer cells activities under different transfection conditions were detected using the Transwell assay and CCK8 assay. The correlation between LINC02418 and patient prognosis was analyzed using multifactor Cox regression and Kaplan-Meier. Results: It was shown that LINC02418 expression was upregulated in breast cancer tissues and cells. There are significant differences in lymph node metastasis and TNM stage between high and low LINC02418 expression groups. The higher the expression of LINC02418, the higher the mortality rate of breast cancer patients. miR-766-5p expression was downregulated and negatively correlated with LINC02418. There are binding sites between LINC02418 and miR-766-5p; Transfection with miR-766-5p inhibitor boosted LINC02418 luciferase activity, but transfection with miR-766-5p mimic decreased it. Knockdown of LINC02418 promoted miR-766-5p expression and inhibited cancer progression, which was alleviated to some extent by transfection with miR-766-5p inhibitors. Conclusion: LINC02418 has the potential to serve as a poor prognostic marker for breast cancer and plays a pro-oncogenic role by targeting miR-766-5p.

Identification of candidate genes for adult plant stripe rust resistance transferred from Aegilops ventricosa 2NvS into wheat via fine mapping and transcriptome analysis.

KEY MESSAGE: An adult plant gene for resistance to stripe rust was narrowed down to the proximal one-third of the 2NvS segment translocated from Aegilops ventricosa to wheat chromosome arm 2AS, and based on the gene expression analysis, two candidate genes were identified showing a stronger response at the adult plant stage compared to the seedling stage. The 2NvS translocation from Aegilops ventricosa, known for its resistance to various diseases, has been pivotal in global wheat breeding for more than three decades. Here, we identified an adult plant resistance (APR) gene in the 2NvS segment in wheat line K13-868. Through fine mapping in a segregating near-isogenic line (NIL) derived population of 6389 plants, the candidate region for the APR gene was narrowed down to between 19.36 Mb and 33 Mb in the Jagger reference genome. Transcriptome analysis in NILs strongly suggested that this APR gene conferred resistance to stripe rust by triggering plant innate immune responses. Based on the gene expression analysis, two disease resistance-associated genes within the candidate region, TraesJAG2A03G00588940 and TraesJAG2A03G00590140, exhibited a stronger response to Puccinia striiformis f. sp. tritici (Pst) infection at the adult plant stage than at the seedling stage, indicating that they could be potential candidates for the resistance gene. Additionally, we developed a co-dominant InDel marker, InDel_31.05, for detecting this APR gene. Applying this marker showed that over one-half of the wheat varieties approved in 2021 and 2022 in Sichuan province, China, carry this gene. Agronomic trait evaluation of NILs indicated that the 2NvS segment effectively mitigated the negative effects of stripe rust on yield without affecting other important agronomic traits. This study provided valuable insights for cloning and breeding through the utilization of the APR gene present in the 2NvS segment.

Synthesis of terpinyl acetate from α-pinene catalyzed by α-hydroxycarboxylic acid-boric acid composite catalyst.

To enhance the yield of the one-step synthesis of terpinyl acetate from α-pinene and acetic acid, this study evaluated α-hydroxycarboxylic acid (HCA)-boric acid composite catalysts based on orthogonal experimental design. The most important factor affecting the terpinyl acetate content in the product was the HCA content. The catalytic performance of the composite catalyst was related to the pKa1 of HCA. The tartaric acid-boric acid composite catalyst showed the highest catalytic activity. The α-pinene conversion reached 91.8%, and the terpinyl acetate selectivity reached 45.6%. When boric acid was replaced with B2O3, the HCA composite catalyst activity was enhanced, which reduced the use of HCA. When the lactic acid and B2O3 content accounted for 10% and 4% of the α-pinene mass content, respectively, the α-pinene conversion reached 93.2%, and the terpinyl acetate selectivity reached up to 47.1%. In addition, the presence of water was unfavorable to HCA-boric acid composite catalyst. However, a water content less than 1% of the α-pinene mass content improved the catalytic activity of HCA-B2O3. When the tartaric acid-B2O3 was used as catalyst, and the water content was 1% of the α-pinene mass content, the α-pinene conversion was 89.6%, and the terpinyl acetate selectivity was 47.5%.

Genome-wide identification of bHLH transcription factors and expression analysis under drought stress in Pseudoroegneria libanotica at germination.

The basic helix-loop-helix (bHLH) transcription factor family is the second largest in plants. bHLH transcription factor is not only universally involved in plant growth and metabolism, including photomorphogenesis, light signal transduction, and secondary metabolism, but also plays an important role in plant response to stress. However, the function of bHLH TFs in Pseudoroegneria species has not been studied yet. Pseudoroegneria (Nevski) Á. Löve is a perennial genus of the Triticeae. Pseudoroegneria species are mostly distributed in arid/semi-arid areas and they show good drought tolerance. In this study, we identified 152 PlbHLH TFs in Pseudoroegneria libanotica, which could be classified into 15 groups. Collinearity analysis indicates that 122 PlbHLH genes share homology with wbHLH genes in wheat, and it has lower homology with AtbHLH genes in Arabidopsis. Based on transcriptome profiling under an experiment with three PEG concentrations (0%, 10%, and 20%), 10 up-regulated genes and 11 down-regulated PlbHLH genes were screened. Among them, PlbHLH6, PlbHLH55 and PlbHLH64 as candidate genes may be the key genes related to drought tolerance response at germination, and they have been demonstrated to respond to drought, salt, oxidative, heat, and heavy metal stress in yeast. This study lays the foundation for an in-depth study of the biological roles of PlbHLHs in Pse. libanotica, and discovered new drought-tolerance candidate genes to enhance the genetic background of Triticeae crops. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01433-w.

Genome constitution and evolution of Elymus atratus (Poaceae: Triticeae) inferred from cytogenetic and phylogenetic analysis.

BACKGROUND: Elymus atratus (Nevski) Hand.-Mazz. is perennial hexaploid wheatgrass. It was assigned to the genus Elymus L. sensu stricto based on morphological characters. Its genome constitution has not been disentangled yet. OBJECTIVE: To identify the genome constitution and origin of E. atratus. METHODS: In this study, genomic in situ hybridization and fluorescence in situ hybridization, and phylogenetic analysis based on the Acc1, DMC1 and matK sequences were performed. RESULTS: Genomic in situ hybridization and fluorescence in situ hybridization results reveal that E. atratus 2n = 6x = 42 is composed of 14 St genome chromosomes, 14 H genome chromosomes, and 14 Y genome chromosomes including two H-Y type translocation chromosomes, suggesting that the genome formula of E. atratus is StStYYHH. The phylogenetic analysis based on Acc1 and DMC1 sequences not only shows that the Y genome originated in a separate diploid, but also suggests that Pseudoroegneria (St), Hordeum (H), and a diploid species with Y genome were the potential donors of E. atratus. Data from chloroplast DNA showed that the maternal donor of E. atratus contains the St genome. CONCLUSION: Elymus atratus is an allohexaploid species with StYH genome, which may have originated through the hybridization between an allotetraploid Roegneria (StY) species as the maternal donor and a diploid Hordeum (H) species as the paternal donor.

How the chemical structure of phosphoramides affect the fire retardancy and mechanical properties of polylactide?

Phosphoramides, as a kind of high-efficient fire retardants, have been designed in many structures and endowed exceptional fire retardancy to polylactide (PLA). However, due to ignorance of the structure-property correlation, the effect of phosphoramides' structure on the fire retardancy and mechanical properties of PLA is still unclear. Herein, a series of biobased phosphoramides (phosphoramide (V1), linear polyphosphoramide (V2) and hyperbranched polyphosphamide (V3)) were designed and incorporated into PLA, and the structural effect of phosphoramides on the fire-retardant and mechanical properties of PLA was deeply researched. Among three kinds of phosphoramides, the hyperbranched polyphosphoramide is more effective than the corresponding linear polyphosphoramide and phosphoramide in improving the fire-retardant and anti-dripping properties of PLA, and only linear polyphosphoramide shows a positive effect in the mechanical strength of PLA. This work provides a feasible strategy for creating mechanically robust and fire-retardant polymer composites by molecularly tailoring the structure of fire retardants and uncovering their structure-property relationship.

Roegneria yenchiana: A new species in the Triticeae (Poaceae) from the Hengduan Mountain region.

Roegneria yenchiana sp. nov. (Triticeae) is a new species collected from Shangri-la of Yunnan Province in China based on morphological, cytological, and molecular data. It is morphologically characterized by one spikelet per node, rectangular glums, awns flanked by two short mucros in lemmas, distinguished from other species of Roegneria. The genomic in situ hybridization results indicate that R. yenchiana is an allotetraploid, and its genomic constitution is StY. Phylogenetic analyses based on multiple loci suggested that R. yenchiana is closely related to Pseudoroegneria and Roegneria, and the Pseudoroegneria served as the maternal donors during its polyploid speciation.