CircHAS2 activates CCNE2 to promote cell proliferation and sensitizes the response of colorectal cancer to anlotinib.

BACKGROUND: Tyrosine kinase inhibitors (TKIs) are crucial in the targeted treatment of advanced colorectal cancer (CRC). Anlotinib, a multi-target TKI, has previously been demonstrated to offer therapeutic benefits in previous studies. Circular RNAs (circRNAs) have been implicated in CRC progression and their unique structural stability serves as promising biomarkers. The detailed molecular mechanisms and specific biomarkers related to circRNAs in the era of targeted therapies, however, remain obscure. METHODS: The whole transcriptome RNA sequencing and function experiments were conducted to identify candidate anlotinib-regulated circRNAs, whose mechanism was confirmed by molecular biology experiments. CircHAS2 was profiled in a library of patient-derived CRC organoids (n = 22) and patient-derived CRC tumors in mice. Furthermore, a prospective phase II clinical study of 14 advanced CRC patients with anlotinib-based therapy was commenced to verify drug sensitivity (ClinicalTrials.gov identifier: NCT05262335). RESULTS: Anlotinib inhibits tumor growth in vitro and in vivo by downregulating circHAS2. CircHAS2 modulates CCNE2 activation by acting as a sponge for miR-1244, and binding to USP10 to facilitate p53 nuclear export as well as degradation. In parallel, circHAS2 serves as a potent biomarker predictive of anlotinib sensitivity, both in patient-derived organoids and xenograft models. Moreover, the efficacy of anlotinib inclusion into the treatment regimen yields meaningful clinical responses in patients with high levels of circHAS2. Our findings offer a promising targeted strategy for approximately 52.9% of advanced CRC patients who have high circHAS2 levels. CONCLUSIONS: CircHAS2 promotes cell proliferation via the miR-1244/CCNE2 and USP10/p53/CCNE2 bidirectional axes. Patient-derived organoids and xenograft models are employed to validate the sensitivity to anlotinib. Furthermore, our preliminary Phase II clinical study, involving advanced CRC patients treated with anlotinib, confirmed circHAS2 as a potential sensitivity marker.

A pH-responsive cetuximab-conjugated DMAKO-20 nano-delivery system for overcoming K-ras mutations and drug resistance in colorectal carcinoma.

Cetuximab (Cet) and oxaliplatin (OXA) are used as first-line drugs for patients with colorectal carcinoma (CRC). In fact, the heterogeneity of CRC, mainly caused by K-ras mutations and drug resistance, undermines the effectiveness of drugs. Recently, a hydrophobic prodrug, (1E,4E)-6-((S)-1-(isopentyloxy)-4-methylpent-3-en-1-yl)-5,8-dimethoxynaphthalene-1,4­dione dioxime (DMAKO-20), has been shown to undergo tumor-specific CYP1B1-catalyzed bioactivation. This process results in the production of nitric oxide and active naphthoquinone mono-oximes, which exhibit specific antitumor activity against drug-resistant CRC. In this study, a Cet-conjugated bioresponsive DMAKO-20/PCL-PEOz-targeted nanocodelivery system (DMAKO@PCL-PEOz-Cet) was constructed to address the issue of DMAKO-20 dissolution and achieve multitargeted delivery of the cargoes to different subtypes of CRC cells to overcome K-ras mutations and drug resistance in CRC. The experimental results demonstrated that DMAKO@PCL-PEOz-Cet efficiently delivered DMAKO-20 to both K-ras mutant and wild-type CRC cells by targeting the epidermal growth factor receptor (EGFR). It exhibited a higher anticancer effect than OXA in K-ras mutant cells and drug-resistant cells. Additionally, it was observed that DMAKO@PCL-PEOz-Cet reduced the expression of glutathione peroxidase 4 (GPX4) in CRC cells and significantly inhibited the growth of heterogeneous HCT-116 subcutaneous tumors and patient-derived tumor xenografts (PDX) model tumors. This work provides a new strategy for the development of safe and effective approaches for treating CRC. STATEMENT OF SIGNIFICANCE: (1) Significance: This work reports a new approach for the treatment of colorectal carcinoma (CRC) using the bioresponsible Cet-conjugated PCL-PEOz/DMAKO-20 nanodelivery system (DMAKO@PCL-PEOz-Cet) prepared with Cet and PCL-PEOz for the targeted transfer of DMAKO-20, which is an anticancer multitarget drug that can even prevent drug resistance, to wild-type and K-ras mutant CRC cells. DMAKO@PCL-PEOz-Cet, in the form of nanocrystal micelles, maintained stability in peripheral blood and efficiently transported DMAKO-20 to various subtypes of colorectal carcinoma cells, overcoming the challenges posed by K-ras mutations and drug resistance. The system's secure and effective delivery capabilities have also been confirmed in organoid and PDX models. (2) This is the first report demonstrating that this approach simultaneously overcomes the K-ras mutation and drug resistance of CRC.

Oxygen-regulated spontaneous solid electrolyte interphase enabling ultra-stable solid-state Na metal batteries.

Solid-state sodium metal batteries utilizing inorganic solid electrolytes (SEs) hold immense potentials such as intrinsical safety, high energy density, and environmental sustainability. However, the interfacial inhomogeneity/instability at the anode-SE interface usually triggers the penetration of sodium dendrites into the electrolyte, leading to short circuit and battery failure. Herein, confronting with the original nonuniform and high-resistance solid electrolyte interphase (SEI) at the Na-Na3Zr2Si2PO12 interface, an oxygen-regulated SEI innovative approach is proposed to enhance the cycling stability of anode-SEs interface, through a spontaneous reaction between the metallic sodium (containing trace amounts of oxygen) and the Na3Zr2Si2PO12 SE. The oxygen-regulated spontaneous SEI is thin, uniform, and kinetically stable to facilitate homogenous interfacial Na+ transportation. Benefitting from the optimized SEI, the assembled symmetric cell exhibits an ultra-stable sodium plating/stripping cycle for over 6600 h under a practical capacity of 3 mAh cm-2. Quasi-solid-state batteries with Na3V2(PO4)3 cathode deliver excellent cyclability over 500 cycles at a rate of 0.5 C (1 C = 117 mA cm-2) with a high capacity retention of 95.4%. This oxygen-regulated SEI strategy may offer a potential avenue for the future development of high-energy-density solid-state metal batteries.

Clinical status and future prospects of single-incision robotic-assisted surgery: a review.

Since the advent of conventional multiport laparoscopic surgery, the prosperity of minimally invasive surgery has been thriving on the advancement of endoscopic techniques. Cosmetic superiority, recovery benefits, and noninferior surgical outcomes weigh single-incision laparoscopic surgery as a promising modality. Although there are surgical challenges posed by steep learning curve and technological difficulties, such as instruments collision, triangulation loss and limited retraction, the establishment of robotic surgical platform as a solution to all is inspiring. Furthermore, with enhanced instrument maneuverability and stability, robotic ergonomic innovations adopt the advantages of single-incision laparoscopic surgery and surmount its recognized barriers by introducing a novel combination, single-incision robotic-assisted surgery. As was gradually diffused in general surgery and other specialties, single-incision robotic-assisted surgery manifests privileges in noninferior clinical outcomes an satisfactory cosmetic effect among strictly selected patients, and has the potential of a preferable surgical option for minimally invasive surgery.

Identification and verification of a prognostic signature based on a miRNA-mRNA interaction pattern in colon adenocarcinoma.

The expression characteristics of non-coding RNA (ncRNA) in colon adenocarcinoma (COAD) are involved in regulating various biological processes. To achieve these functions, ncRNA and a member of the Argonaute protein family form an RNA-induced silencing complex (RISC). The RISC is directed by ncRNA, especially microRNA (miRNA), to bind the target complementary mRNAs and regulate their expression by interfering with mRNA cleavage, degradation, or translation. However, how to identify potential miRNA biomarkers and therapeutic targets remains unclear. Here, we performed differential gene screening based on The Cancer Genome Atlas dataset and annotated meaningful differential genes to enrich related biological processes and regulatory cancer pathways. According to the overlap between the screened differential mRNAs and differential miRNAs, a prognosis model based on a least absolute shrinkage and selection operator-based Cox proportional hazards regression analysis can be established to obtain better prognosis characteristics. To further explore the therapeutic potential of miRNA as a target of mRNA intervention, we conducted an immunohistochemical analysis and evaluated the expression level in the tissue microarray of 100 colorectal cancer patients. The results demonstrated that the expression level of POU4F1, DNASE1L2, and WDR72 in the signature was significantly upregulated in COAD and correlated with poor prognosis. Establishing a prognostic signature based on miRNA target genes will help elucidate the molecular pathogenesis of COAD and provide novel potential targets for RNA therapy.

Functional analysis of polyphenol oxidase 1 gene in common wheat.

Polyphenol oxidase (PPO) activity is a major cause of the undesirable brown color of wheat-based products. Ppo1, a major gene for PPO activity, was cloned based on sequence homology in previous studies; however, its function and regulation mechanism remain unclear. In this study, the function and genetic regulation of Ppo1 were analyzed using RNA interference (RNAi) and Targeting Induced Local Lesions IN Genomes (TILLING) technology, and superior mutants were identified. Compared with the control, the level of Ppo1 transcript in RNAi transgenic lines was drastically decreased by 15.5%-60.9% during grain development, and PPO activity was significantly reduced by 12.9%-20.4%, confirming the role of Ppo1 in PPO activity. Thirty-two Ppo1 mutants were identified in the ethyl methanesulfonate (EMS)-mutagenized population, including eight missense mutations, 16 synonymous mutations, and eight intron mutations. The expression of Ppo1 was reduced significantly by 6.7%-37.1% and 10.1%-54.4% in mutants M092141 (G311S) and M091098 (G299R), respectively, in which PPO activity was decreased by 29.7% and 28.8%, respectively, indicating that mutation sites of two mutants have important effects on PPO1 function. Sequence and structure analysis revealed that the two sites were highly conserved among 74 plant species, where the frequency of glycine was 94.6% and 100%, respectively, and adjacent to the entrance of the hydrophobic pocket of the active site. The M092141 and M091098 mutants can be used as important germplasms to develop wheat cultivars with low grain PPO activity. This study provided important insights into the molecular mechanism of Ppo1 and the genetic improvement of wheat PPO activity.

Slow stripe rusting in Chinese wheat Jimai 44 conferred by Yr29 in combination with a major QTL on chromosome arm 6AL.

KEY MESSAGE: YrJ44, a more effective slow rusting gene than Yr29, was localized to a 3.5-cM interval between AQP markers AX-109373479 and AX-109563479 on chromosome 6AL. "Slow rusting" (SR) is a type of adult plant resistance (APR) that can provide non-specific durable resistance to stripe rust in wheat. Chinese elite wheat cultivar Jimai 44 (JM44) has maintained SR to stripe rust in China since its release despite exposure to a changing and variable pathogen population. An F2:6 population comprising 295 recombinant inbred lines (RILs) derived from a cross between JM44 and susceptible cultivar Jimai 229 (JM229) was used in genetic analysis of the SR. The RILs and parental lines were evaluated for stripe rust response in five field environments and genotyped using the Affymetrix Wheat55K SNP array and 13 allele-specific quantitative PCR-based (AQP) markers. Two stable QTL on chromosome arms 1BL and 6AL were identified by inclusive composite interval mapping. The 1BL QTL was probably the pleiotropic gene Lr46/Yr29/Sr58. QYr.nwafu-6AL (hereafter named YrJ44), mapped in a 3.5-cM interval between AQP markers AX-109373479 and AX-109563479, was more effective than Yr29 in reducing disease severity and relative area under the disease progress curve (rAUDPC). RILs harboring both YrJ44 and Yr29 displayed levels of SR equal to the resistant parent JM44. The AQP markers linked with YrJ44 were polymorphic and significantly correlated with stripe rust resistance in a panel of 1,019 wheat cultivars and breeding lines. These results suggested that adequate SR resistance can be obtained by combining YrJ44 and Yr29 and the AQP markers can be used in breeding for durable stripe rust resistance.

Heterozygous inversion breakpoints suppress meiotic crossovers by altering recombination repair outcomes.

Heterozygous chromosome inversions suppress meiotic crossover (CO) formation within an inversion, potentially because they lead to gross chromosome rearrangements that produce inviable gametes. Interestingly, COs are also severely reduced in regions nearby but outside of inversion breakpoints even though COs in these regions do not result in rearrangements. Our mechanistic understanding of why COs are suppressed outside of inversion breakpoints is limited by a lack of data on the frequency of noncrossover gene conversions (NCOGCs) in these regions. To address this critical gap, we mapped the location and frequency of rare CO and NCOGC events that occurred outside of the dl-49 chrX inversion in D. melanogaster. We created full-sibling wildtype and inversion stocks and recovered COs and NCOGCs in the syntenic regions of both stocks, allowing us to directly compare rates and distributions of recombination events. We show that COs outside of the proximal inversion breakpoint are distributed in a distance-dependent manner, with strongest suppression near the inversion breakpoint. We find that NCOGCs occur evenly throughout the chromosome and, importantly, are not suppressed near inversion breakpoints. We propose a model in which COs are suppressed by inversion breakpoints in a distance-dependent manner through mechanisms that influence DNA double-strand break repair outcome but not double-strand break formation. We suggest that subtle changes in the synaptonemal complex and chromosome pairing might lead to unstable interhomolog interactions during recombination that permits NCOGC formation but not CO formation.

Identification of a Pm4 Allele Conferring Powdery Mildew Resistance in Wheat Breeding Line GR18-1.

Powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is a serious fungal wheat disease of wheat worldwide. Host resistance is considered to be the most environmentally friendly and efficient approach against this disease. Wheat breeding line GR18-1 showed resistance to powdery mildew at both seedling and adult stages for several years. Genetic analysis indicated that a single dominant gene, tentatively designated as PmGR-18, conferred powdery mildew resistance in GR18-1. Bulked segregant analysis and marker analysis showed that PmGR-18 was located in the Pm4 interval on chromosome arm 2AL and was flanked by the markers Xwgrc763 and Xwgrc872, respectively, with genetic distances of 0.5 and 1.0 cM corresponding to a physical interval of 1.13 Mb based on the Chinese Spring reference genome sequence v2.1. Using homology-based cloning and Sanger sequencing, we found that the sequence of PmGR-18 was totally consistent with that of Pm4d. qRT-PCR analysis showed that the expression levels of two splicing variants Pm4d_V1 and Pm4d_V2 in GR18-1 were significantly upregulated after inoculating with Bgt isolate E09, and the level of Pm4d_V2 was significantly lower than that of Pm4d_V1 at most of the time points, suggesting a different resistance pattern may be involved in the genotype. To facilitate the transfer of PmGR-18 in marker-assisted selection (MAS) breeding, the flanked markers Xwgrc763 and Xwgrc872 and the functional marker JS717/JS718 were tested and confirmed to enable the tracking of PmGR-18 when it transferred into those susceptible cultivars.

Rh(III)-Catalyzed Defluorinative [4 + 2] Annulation of N-Sulfonylarylamides with Ethyl 2-Diazo-3,3,3-trifluoropropanoate: Synthesis of 1,3,4-Functionalized Isoquinolines.

Using 2-diazo-3,3,3-trifluoropropanoate as a nontraditional two-carbon reaction partner, a Rh(III)-catalyzed defluorinative [4 + 2] annulation for the synthesis of 1,3,4-functionalized isoquinolines was developed. The reaction proceeds by sequential C-H carbenoid insertion, dual C-F bond cleavage/annulation, and N- to O-sulfonyl migration. The resultant products were converted to diverse 1,3,4-trisubstituted isoquinolines based on the functionalization of the newly installed 1-sulfonate, 2-fluoro functional handles, and/or remaining ester motif.

Excessive HSP70/TLR2 activation leads to remodeling of the tumor immune microenvironment to resist chemotherapy sensitivity of mFOLFOX in colorectal cancer.

For locally advanced colorectal cancer (CRC), neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision or complete mesocolic excision is the standard therapeutic strategy, which is key to patient survival. Involvement of the tumor immune microenvironment is a factor that regulates tumor progression and sensitivity to nCRT in CRC. In this study, we aimed to identify the effect of heat-shock protein 70 (HSP70)/toll-like receptor-2 (TLR-2) on mFOLFOX sensitization for CRC. A total of 22 patients with advanced CRC who had received neoadjuvant mFOLFOX were enrolled and classified into the mFOLFOX-insensitive or -sensitive group, according to the tumor regression grade. The abundance of immune infiltrates was significantly higher in the post-operative pathological specimens of the mFOLFOX-insensitive group, as compared to those of the mFOLFOX-sensitive group. After transcriptome sequencing, differentially expressed genes between the two groups were annotated to inflammatory and immune responses using Gene Ontology (GO) analysis, and the TLR signaling pathway was analyzed using Kyoto Encyclopedia of Genes and Genomes pathway analysis. Significantly higher expression levels of HSP60, HSP70, HSP90, and TLR-2 in the mFOLFOX-insensitive group were detected using immunofluorescence assays. TIMER2.0 platform was introduced to further narrow the scope of HSP70 (HSPA6 or HSPA7) and TLR-2, which exhibited positive correlations with dendritic cells, Tregs, or CD4+ T cells and negative correlations with CD3+ or CD8+ T cells, implying that HSP70/TLR-2 activation mediates immunosuppressive cells to counteract CD8+ T cells, which may be a novel target of CRC treatment. A promising synergistic effect of mFOLFOX combined with a TLR-2 inhibitor was observed in vivo in mouse allograft models, which could be partly rescued by recombinant HSP70 protein. Immunohistochemical staining of allografts and immunofluorescence assays of clinical specimens corroborated the regulatory effects of the immune microenvironment. In summary, HSP70/TLR-2 activation can regulate the tumor immune microenvironment of CRC and further remodel its sensitivity to mFOLFOX. However, the specific mechanisms remain unclear and require further investigation. This study is expected to provide a new direction for the clinical treatment of CRC.

Latticed-Confined Conversion Chemistry of Battery Electrode.

The electrochemical conversion reaction, usually featured by multiple redox processes and high specific capacity, holds great promise in developing high-energy rechargeable battery technologies. However, the complete structural change accompanied by spontaneous atomic migration and volume variation during the charge/discharge cycle leads to electrode disintegration and performance degradation, therefore severely restricting the application of conventional conversion-type electrodes. Herein, latticed-confined conversion chemistry is proposed, where the "intercalation-like" redox behavior is realized on the electrode with a "conversion-like" high capacity. By delicately formulating the high-entropy compounds, the pristine crystal structure can be preserved by the inert lattice framework, thus enabling an ultra-high initial Coulombic efficiency of 92.5% and a long cycling lifespan over a thousand cycles after the quasistatic charge-discharge cycle. This lattice-confined conversion chemistry unfolds a ubiquitous insight into the localized redox reaction and sheds light on developing high-performance electrodes toward next-generation high-energy rechargeable batteries.

Apatinib: A Novel Antiangiogenic Drug in Monotherapy or Combination Immunotherapy for Digestive System Malignancies.

Digestive system malignancies are one of the primary causes of cancer-related death. Meanwhile, angiogenesis has been proved to play an important role in the process of cancer neovascularization. Apatinib, a novel targeted antiangiogenic molecule, could generate highly selective competition in the vascular endothelial growth factor receptor-2, involved in tumor progression and metastasis. It has been implied as a promising cancer treatment agent that can prevent tumor cell proliferation meanwhile inhibit tumor angiogenesis. Furthermore, completed clinical trials demonstrated that apatinib could prolong the progression-free survival and overall survival in advanced gastric cancer and primary liver cancer. Recent studies revealed that apatinib had a synergistic effect with immunotherapy as a second-line and third-line treatment regimen for some other cancers. In this review, we summarize the pharmacological properties of apatinib and the latest clinical application in chemotherapy-refractory patients with advanced digestive system cancer. Based on the comparable survival results, the molecular mechanisms of apatinib are prospective to include the antiangiogenic, apoptosis-inducing, and autophagy-inducing properties in the corresponding signaling pathway. Treatment of apatinib monotherapy or combination immunotherapy remains the optimal option for patients with digestive system malignancies in the future.

Molecular and Cytogenetic Identification of Stem Rust Resistant Wheat-Thinopyrum intermedium Introgression Lines.

Thinopyrum intermedium (JJJsJsStSt, 2n = 6x = 42), a wild relative of common wheat, possesses many desirable agronomic genes for wheat improvement. The production of wheat-Thinopyrum intermedium introgression lines is a key step for transferring these beneficial genes into wheat. In this study, we characterized three wheat-Thinopyrum intermedium introgression lines TA3681, TA5566, and TA5567 using non-denaturing fluorescence in situ hybridization, genomic in situ hybridization, PCR-based landmark unique gene, and intron targeting markers. Our results showed that TA3681 is a wheat-Thinopyrum intermedium 1St disomic addition line, TA5566 is a wheat-Thinopyrum intermedium non-Robertsonian translocation line carrying two pairs of 3A-7Js translocation chromosomes, and that TA5567 is a wheat-Thinopyrum intermedium non-Robertsonian translocation line carrying a pair of 3A-7Js translocation chromosomes. We developed 13, 36, and 15 Thinopyrum intermedium chromosome-specific markers for detecting the introgressed Thinopyrum chromosomes in TA3681, TA5566, and TA5567, respectively. Stem rust assessment revealed that TA3681 exhibited a high level of seedling resistance to Chinese-prevalent Puccinia graminis f. sp. tritici pathotypes, and both TA5566 and TA5567 were highly resistant to Australian P. graminis f. sp. tritici pathotypes, indicating that Thinopyrum intermedium chromosomes 1St and 7Js might carry new stem rust resistance genes. Therefore, the new identified introgression lines may be useful for improving wheat stem rust resistance.

Genetically Dissecting the Novel Powdery Mildew Resistance Gene in Wheat Breeding Line PBDH1607.

Powdery mildew is one of the most destructive diseases in wheat production. Identifying novel resistance genes and deploying them in new cultivars is the most effective approach to minimize wheat losses caused by powdery mildew. In this study, wheat breeding line PBDH1607 showed high resistance to powdery mildew at both the seedling and adult plant stages. Genetic analysis of the seedling data demonstrated that the resistance was controlled by a single dominant gene, tentatively designated PmPBDH. The ΔSNP index based on bulked segregant RNA sequencing indicated that PmPBDH was associated with an interval of about 30.8 Mb (713.5 to 744.3 Mb) on chromosome arm 4AL. Using newly developed markers, we mapped PmPBDH to a 3.2-cM interval covering 7.1 Mb (719,055,516 to 726,215,121 bp). This interval differed from those of Pm61 (717,963,176 to 719,260,469 bp), MlIW30 (732,769,506 to 732,790,522 bp), and MlNSF10 (729,275,816 to 731,365,462 bp) reported on the same chromosome arm. PmPBDH also differed from Pm61, MlIW30, and MlNSF10 by its response spectrum, origin, or inheritance mode, suggesting that PmPBDH should be a new Pm gene. In the candidate interval, five genes were found to be associated with PmPBDH via time course gene expression analysis, and thus they are candidate genes of PmPBDH. Six closely linked markers, including two kompetitive allele-specific PCR markers, were confirmed to be applicable for tracking PmPBDH in marker-assisted breeding.

Identification and Evaluation of Wheat-Aegilops bicornis Lines with Resistance to Powdery Mildew and Stripe Rust.

Wheat pathogens, especially those causing powdery mildew and stripe rust, seriously threaten yield worldwide. Utilizing newly identified disease resistance genes from wheat relatives is an effective strategy to minimize disease damage. In this study, chromosome-specific molecular markers for the 3Sb and 7Sb chromosomes of Aegilops bicornis were developed using PCR-based landmark unique gene primers for screening wheat-A. bicornis progenies. Fluorescence in situ hybridization (FISH) was performed to further identify wheat-A. bicornis progenies using oligonucleotides probes Oligo-pSc119.2-1, Oligo-pTa535-1, and Oligo-(GAA)8. After establishing A. bicornis 3Sb and 7Sb chromosome-specific FISH markers, Holdfast (common wheat)-A. bicornis 3Sb addition, 7Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, 3Sb(3D) substitution, 7Sb(7A) substitution, and 7Sb(7B) substitution lines were identified by the molecular and cytological markers. Stripe rust and powdery mildew resistance, along with agronomic traits, were investigated to evaluate the breeding potential of these lines. Holdfast and Holdfast-A. bicornis progenies were all highly resistant to stripe rust, indicating that the stripe rust resistance might derive from Holdfast. However, Holdfast-A. bicornis 3Sb addition, 3Sb(3A) substitution, 3Sb(3B) substitution, and 3Sb(3D) substitution lines showed high resistance to powdery mildew while Holdfast was highly susceptible, indicating that chromosome 3Sb of A. bicornis carries previously unknown powdery mildew resistance gene(s). Additionally, the transfer of the 3Sb chromosome from A. bicornis to wheat significantly increased tiller number, but chromosome 7Sb has a negative effect on agronomic traits. Therefore, wheat germplasm containing A. bicornis chromosome 3Sb has potential to contribute to improving powdery mildew resistance and tiller number during wheat breeding.

Effects of the different waxy proteins on starch biosynthesis, starch physicochemical properties and Chinese noodle quality in wheat.

Noodles are an important food in Asia. Wheat starch is the most important component in Chinese noodles. Loss of the waxy genes leads to lower activity of starch synthesis enzymes and decreased amylose content that further affects starch properties and noodle quality. To study the effects of different waxy (Wx) protein subunits on starch biosynthesis and processing quality, the high-yielding wheat cultivar Jimai 22 was treated with the mutagen ethyl methane sulfonate (EMS) to produce a population of Wx lines and chosen 7 Wx protein combinations. The amylose content increased but swelling power decreased as the number of Wx proteins increased. Both GBSS activity and gene expression were the lowest for the waxy mutant, followed by the mutants with 1 Wx protein. The combinations of these mutant alleles lead to reductions in both RNA expression and protein levels. Noodles made from materials with 2 Wx protein subunits had the highest score, which agreed with peak viscosity. The influence of the Wx-B1 protein on amylose synthesis and noodle quality was the highest, whereas the influence of Wx-A1 protein was the lowest. Mutants with lower amylose content caused by the absence of 1 subunit, especially the Wx-B1 subunit, had superior noodle quality. Additionally, the identified mutant lines can be used as intermediate materials to improve wheat quality. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01292-x.

Characterization, Identification and Evaluation of Wheat-Aegilops sharonensis Chromosome Derivatives.

Aegilops sharonensis, a wild relative of wheat, harbors diverse disease and insect resistance genes, making it a potentially excellent gene source for wheat improvement. In this study, we characterized and evaluated six wheat-A. sharonensis derivatives, which included three disomic additions, one disomic substitution + monotelosomic addition and two disomic substitution + disomic additions. A total of 51 PLUG markers were developed and used to allocate the A. sharonensis chromosomes in each of the six derivatives to Triticeae homoeologous groups. A set of cytogenetic markers specific for A. sharonensis chromosomes was established based on FISH using oligonucleotides as probes. Molecular cytogenetic marker analysis confirmed that these lines were a CS-A. sharonensis 2Ssh disomic addition, a 4Ssh disomic addition, a 4Ssh (4D) substitution + 5SshL monotelosomic addition, a 6Ssh disomic addition, a 4Ssh (4D) substitution + 6Ssh disomic addition and a 4Ssh (4D) substitution + 7Ssh disomic addition line, respectively. Disease resistance investigations showed that chromosome 7Ssh of A. sharonensis might harbor a new powdery mildew resistance gene, and therefore it has potential for use as resistance source for wheat breeding.