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In holometabolous insects, such as Drosophila and Bombyx, prothoracicotropic hormone (PTTH) is well established to be critical in controlling developmental transitions and metamorphosis by stimulating the biosynthesis of ecdysone in the prothoracic glands (PGs). However, the physiological role of PTTH and the receptor Torso in hemimetabolous insects remains largely unexplored. In this study, homozygous PTTH- and Torso-null mutants of the brown planthopper (BPH), Nilaparvata lugens, were successfully generated by employing clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR–Cas9). Further characterization showed that both NlPTTH−/− and NlTorso−/− mutants exhibited prolonged nymphal duration and increased final adult size. Enzyme-linked immunosorbent assay (ELISA) revealed that NlPTTH−/− and NlTorso−/− mutants exhibited a significant reduction in 20-hydroxyecdysone (20E) in fifth-instar nymphs at 48 h post-ecdysis compared to Wt controls. Furthermore, our results indicated that both NlPTTH−/− and NlTorso−/− mutants had shortened lifespan, reduced female fecundity, and reduced egg hatching rates in adults. These findings suggest a conserved role for the PTTH–Torso signaling system in the regulation of developmental transitions by stimulating ecdysone biosynthesis in hemimetabolous insects. [ABSTRACT FROM AUTHOR]

Summary: Wheat needs different durations of vernalization, which accelerates flowering by exposure to cold temperature, to ensure reproductive development at the optimum time, as that is critical for adaptability and high yield. TaVRN1 is the central flowering regulator in the vernalization pathway and encodes a MADS‐box transcription factor (TF) that usually works by forming hetero‐ or homo‐dimers. We previously identified that TaVRN1 bound to an MADS‐box TF TaSOC1 whose orthologues are flowering activators in other plants. The specific function of TaSOC1 and the biological implication of its interaction with TaVRN1 remained unknown. Here, we demonstrated that TaSOC1 was a flowering repressor in the vernalization and photoperiod pathways by overexpression and knockout assays. We confirmed the physical interaction between TaSOC1 and TaVRN1 in wheat protoplasts and in planta, and further validated their genetic interplay. A Flowering Promoting Factor 1‐like gene TaFPF1‐2B was identified as a common downstream target of TaSOC1 and TaVRN1 through transcriptome and chromatin immunoprecipitation analyses. TaSOC1 competed with TaVRT2, another MADS‐box flowering regulator, to bind to TaVRN1; their coding genes synergistically control TaFPF1‐2B expression and flowering initiation in response to photoperiod and low temperature. We identified major haplotypes of TaSOC1 and found that TaSOC1‐Hap1 conferred earlier flowering than TaSOC1‐Hap2 and had been subjected to positive selection in wheat breeding. We also revealed that wheat SOC1 family members were important domestication loci and expanded by tandem and segmental duplication events. These findings offer new insights into the regulatory mechanism underlying flowering control along with useful genetic resources for wheat improvement. [ABSTRACT FROM AUTHOR]

Summary: Timely flowering is essential for optimum crop reproduction and yield. To determine the best flowering‐time genes (FTGs) relevant to local adaptation and breeding, it is essential to compare the interspecific genetic architecture of flowering in response to light and temperature, the two most important environmental cues in crop breeding. However, the conservation and variations of FTGs across species lack systematic dissection. This review summarizes current knowledge on the genetic architectures underlying light and temperature‐mediated flowering initiation in Arabidopsis, rice, and temperate cereals. Extensive comparative analyses show that most FTGs are conserved, whereas functional variations in FTGs may be species specific and confer local adaptation in different species. To explore evolutionary dynamics underpinning the conservation and variations in FTGs, domestication and selection of some key FTGs are further dissected. Based on our analyses of genetic control of flowering time, a number of key issues are highlighted. Strategies for modulation of flowering behavior in crop breeding are also discussed. The resultant resources provide a wealth of reference information to uncover molecular mechanisms of flowering in plants and achieve genetic improvement in crops. [ABSTRACT FROM AUTHOR]

Summary: FLOWERING LOCUS T (FT) protein, physiologically florigen, has been identified as a system integrator of numerous flowering time pathways in many studies, and its homologs are found throughout the plant lineage. It is important to uncover how precisely florigenic homologs contribute to flowering initiation and how these factors interact genetically. Here we dissected the function of Brachypodium FT orthologs BdFTL1 and BdFTL2 using overexpression and gene‐editing experiments. Transgenic assays showed that both BdFTL1 and BdFTL2 could promote flowering, whereas BdFTL2 was essential for flowering initiation. Notably, BdFTL1 is subject to alternative splicing (AS), and its transcriptional level and AS are significantly affected by BdFTL2. Additionally, BdFTL2 could bind with the PHD‐containing protein BdES43, an H3K4me3 reader. Furthermore, BdES43 was antagonistic to BdFTL2 in flowering initiation in a transcription‐dependent manner and significantly affected BdFTL1 expression. BdFTL2, BdES43 and H3K4me3 also had highly similar distribution patterns within the BdFTL1 locus, indicating their interplay in regulating target genes. Taken together, florigen BdFTL2 functions as a potential epigenetic effector of BdFTL1 by interacting with a BdES43‐H3K4me3 complex. This finding provides an additional insight for the regulatory mechanism underlying the multifaceted roles of florigen. Significance Statement: FLOWERING LOCUS T (FT) protein, physiologically florigen, is a signal integrator in flowering pathways and function in multiple other development processes. Here we achieved the functional dissection of Brachypodium FT homologs BdFTL1 and BdFTL2 by gene‐editing technology, observed their epistatic interaction, and revealed that a BdES43 and H3K4me3 complex might mediate BdFTL2 in regulating BdFTL1. These findings provide an additional entry point to explore the molecular basis for florigen's pleiotropic effects on plant development. [ABSTRACT FROM AUTHOR]

Summary: High‐molecular‐weight glutenin subunits (HMW‐GS), a major component of seed storage proteins (SSP) in wheat, largely determine processing quality. HMW‐GS encoded by GLU‐1 loci are mainly controlled at the transcriptional level by interactions between cis‐elements and transcription factors (TFs). We previously identified a conserved cis‐regulatory module CCRM1‐1 as the most essential cis‐element for Glu‐1 endosperm‐specific high expression. However, the TFs targeting CCRM1‐1 remained unknown. Here, we built the first DNA pull‐down plus liquid chromatography‐mass spectrometry platform in wheat and identified 31 TFs interacting with CCRM1‐1. TaB3‐2A1 as proof of concept was confirmed to bind to CCRM1‐1 by yeast one hybrid and electrophoretic mobility shift assays. Transactivation experiments demonstrated that TaB3‐2A1 repressed CCRM1‐1‐driven transcription activity. TaB3‐2A1 overexpression significantly reduced HMW‐GS and other SSP, but enhanced starch content. Transcriptome analyses confirmed that enhanced expression of TaB3‐2A1 down‐regulated SSP genes and up‐regulated starch synthesis‐related genes, such as TaAGPL3, TaAGPS2, TaGBSSI, TaSUS1 and TaSUS5, suggesting that it is an integrator modulating the balance of carbon and nitrogen metabolism. TaB3‐2A1 also had significant effects on agronomic traits, including heading date, plant height and grain weight. We identified two major haplotypes of TaB3‐2A1 and found that TaB3‐2A1‐Hap1 conferred lower seed protein content, but higher starch content, plant height and grain weight than TaB3‐2A1‐Hap2 and was subjected to positive selection in a panel of elite wheat cultivars. These findings provide a high‐efficiency tool to detect TFs binding to targeted promoters, considerable gene resources for dissecting regulatory mechanisms underlying Glu‐1 expression, and a useful gene for wheat improvement. [ABSTRACT FROM AUTHOR]

Key message: We identified stable QTL for grain morphology and yield component traits in a wheat defective grain filling line and validated genetic effects in a panel of cultivars using breeding-relevant markers. Grain filling capacity is essential for grain yield and appearance quality in cereal crops. Identification of genetic loci for grain filling is important for wheat improvement. However, there are few genetic studies on grain filling in wheat. Here, a defective grain filling (DGF) line wdgf1 characterized by shrunken grains was identified in a population derived from multi-round crosses involving nine parents and a recombinant inbreed line (RIL) population was generated from the cross between wdgf1 and a sister line with normal grains. We constructed a genetic map of the RIL population using the wheat 15K single nucleotide polymorphism chip and detected 25 stable quantitative trait loci (QTL) for grain morphology and yield components, including three for DGF, eleven for grain size, six for thousand grain weight, three for grain number per spike and two for spike number per m2. Among them, QDGF.caas-7A is co-located with QTGW.caas-7A and can explain 39.4–64.6% of the phenotypic variances, indicating that this QTL is a major locus controlling DGF. Sequencing and linkage mapping showed that TaSus2-2B and Rht-B1 were candidate genes for QTGW.caas-2B and the QTL cluster (QTGW.caas-4B, QGNS.caas-4B, and QSN.caas-4B), respectively. We developed kompetitive allele-specific PCR markers tightly linked to the stable QTL without corresponding to known yield-related genes, and validated their genetic effects in a diverse panel of wheat cultivars. These findings not only lay a solid foundation for genetic dissection underlying grain filling and yield formation, but also provide useful tools for marker-assisted breeding. [ABSTRACT FROM AUTHOR]

Key message: We fine mapped RHT26 for plant height in wheat, confirmed its genetic effects in a panel of wheat cultivars and predicted candidate genes. Development of wheat cultivars with appropriate plant height (PH) is an important goal in breeding. Utilization of semi-dwarfing genes Rht-B1b and Rht-D1b triggered wheat Green Resolution in the 1960s. Since these genes also bring unfavorable features, such as reduced coleoptile length and grain weight, it is necessary to identify alternative reduced height genes without yield penalty. Here we constructed a high-density genetic map of a recombinant inbred line population derived from the cross of Zhongmai175 and Lunxuan987 and detected a stable genetic locus for PH, designated RHT26, on chromosome arm 3DL in all of six environments, accounting for 6.8–14.0% of the phenotypic variances. RHT26 was delimited to an approximate 1.4 Mb physical interval (517.1–518.5 Mb) using secondary mapping populations derived from 22 heterozygous recombinant plants and 24 kompetitive allele-specific PCR markers. Eleven high-confidence genes were annotated in the physical interval according to the Chinese Spring reference genome, and four of them were predicted as candidates for RHT26 based on genome and transcriptome sequencing analyses. We also confirmed that RHT26 had significant effects on PH, but not grain yield in a panel of wheat cultivars; its dwarfing allele has been frequently used in wheat breeding. These findings lay a sound foundation for map-based cloning of RHT26 and provide a breeding-applicable tool for marker-assisted selection. [ABSTRACT FROM AUTHOR]

Acer rubrum L. is one of the most prevalent ornamental species of the genus Acer, due to its straight and tall stems and beautiful leaf colors. For this study, the Oxford Nanopore platform and Hi-C technology were employed to obtain a chromosome-scale genome for A. rubrum. The genome size of A. rubrum was 1.69 Gb with an N50 of 549.44 Kb, and a total of 39 pseudochromosomes were generated with a 99.61% genome. The A. rubrum genome was predicted to have 64644 genes, of which 97.34% were functionally annotated. Genome annotation identified 67.14% as the transposable element (TE) repeat sequence, with long terminal repeats (LTR) being the richest (55.68%). Genome evolution analysis indicated that A. rubrum diverged from A. yangbiense ∼6.34 million years ago. We identified 13 genes related to pigment synthesis in A. rubrum leaves, where the expressions of four ArF3′H genes were consistent with the synthesis of cyanidin (a key pigment) in red leaves. Correlation analysis verified that the pigmentation of A. rubrum leaves was under the coordinated regulation of non-structural carbohydrates and hormones. The genomic sequence of A. rubrum will facilitate genomic breeding research for this species, while providing the valuable utilization of Aceraceae resources. • The chromosome-scale genome of A. rubrum was obtained. • An advance in the determination of complex genomes in polyploid plants. • Regulatory among pigments, hormones, and carbohydrates in A. rubrum leaves. [ABSTRACT FROM AUTHOR]

Key message: We fine mapped QTL QTKW.caas-5DL for thousand kernel weight in wheat, predicted candidate genes and developed a breeding-applicable marker. Thousand kernel weight (TKW) is an important yield component trait in wheat, and identification of the underlying genetic loci is helpful for yield improvement. We previously identified a stable quantitative trait locus (QTL) QTKW.caas-5DL for TKW in a Doumai/Shi4185 recombinant inbred line (RIL) population. Here we performed fine mapping of QTKW.caas-5DL using secondary populations derived from 15 heterozygous recombinants and delimited the QTL to an approximate 3.9 Mb physical interval from 409.9 to 413.8 Mb according to the Chinese Spring (CS) reference genome. Analysis of genomic synteny showed that annotated genes in the physical interval had high collinearity among CS and eight other wheat genomes. Seven genes with sequence variation and/or differential expression between parents were predicted as candidates for QTKW.caas-5DL based on whole-genome resequencing and transcriptome assays. A kompetitive allele-specific PCR (KASP) marker for QTKW.caas-5DL was developed, and genotyping confirmed a significant association with TKW but not with other yield component traits in a panel of elite wheat cultivars. The superior allele of QTKW.caas-5DL was frequent in a panel of cultivars, suggesting that it had undergone positive selection. These findings not only lay a foundation for map-based cloning of QTKW.caas-5DL but also provide an efficient tool for marker-assisted selection. [ABSTRACT FROM AUTHOR]

Summary: TaVrn1, encoding a MADS‐box transcription factor (TF), is the central regulator of wheat vernalization‐induced flowering. Considering that the MADS‐box TF usually works by forming hetero‐ or homodimers, we conducted yeast‐two‐hybrid screening and identified an SVP‐like MADS‐box protein TaVrt2 interacting with TaVrn1. However, the specific function of TaVrt2 and the biological implication of its interaction with TaVrn1 remained unknown.We validated the function of TaVrt2 and TaVrn1 by wheat transgenic experiments and their interaction through multiple protein‐binding assays. Population genetic analysis also was used to display their interplay. Transcriptomic sequencing and chromatin immunoprecipitation assays were performed to identify their common targets.TaVrt2 and TaVrn1 are flowering promoters in the vernalization pathway and interact physically in vitro, in planta and in wheat cells. Additionally, TaVrt2 and TaVrn1 were significantly induced in leaves by vernalization, suggesting their spatio‐temporal interaction during vernalization. Genetic analysis indicated that TaVrt2 and TaVrn1 had significant epistatic effects on flowering time. Furthermore, native TaVrn1 was up‐regulated significantly in TaVrn1‐OE (overexpression) and TaVrt2‐OE lines. Moreover, TaVrt2 could bind with TaVrn1 promoter directly.A TaVrt2‐mediated positive feedback loop of TaVrn1 during vernalization was proposed, providing additional understanding on the regulatory mechanism underlying vernalization‐induced flowering. [ABSTRACT FROM AUTHOR]

Ferulic acid is an important bioactive compound in wheat grains and has great effect on dietary health. Identification of genetic loci can facilitate breeding wheat cultivars with higher ferulic acid content (FAC). Here a genome-wide association study (GWAS) was conducted to identify genetic loci controlling FAC in wheat grain using 90K and 660K chips in a diversity panel of wheat cultivars. Eight major loci for FAC, FAC-1B , FAC-2A , FAC-4A-I , FAC-4A-II , FAC-6B , FAC-7B – I , FAC-7B - II and FAC-7B - III were detected and each explained approximately 10% of the phenotypic variances. The favorable alleles of the major loci have significantly accumulative effects on FAC. A group of varieties with more favorable alleles and higher FAC was also identified according to genotypic and phenotypic analyses. Two SNPs closely associated with FAC-4A-I and FAC-6B , respectively, were successfully converted to flexible kompetitive allele-specific PCR (KASP) markers to facilitate marker-assisted selection in breeding. The findings not only supply useable materials for food industry and breeding, but also lay a foundation for dissecting genetic architecture underpinning FAC in wheat. [Display omitted] • Identification of wheat genetic loci for ferulic acid content (FAC) facilitates breeding high-FAC varieties. • Major loci for FAC and wheat varieties with more favorable alleles and higher FAC were identified using SNP chips. • These outcomes dissected genetic architecture underpinning FAC and provided useable materials and tools for wheat high-FAC breeding. [ABSTRACT FROM AUTHOR]

CCHamides are newly identified insect neuropeptides, which are widely occurring in most insects. However, our knowledge about their signaling characteristics and physiological roles is still limited. Here, we cloned two full-length cDNAs encoding putative CCHamide receptors, Bombyx neuropeptide GPCR A14 (BNGR-A14) and -A15 (BNGR-A15), from the brain of B. mori larvae. Characterization of signaling indicated that Bombyx CCHamide-1 and CCHamide-2 are specific endogenous ligands for BNGR-A15 and BNGR-A14, respectively. Further functional assays combined with specific inhibitors demonstrated that upon activation by CCHamide-2, BNGR-A14 elicited significant increases in CRE-driven luciferase activity, intracellular Ca2+ mobilization and ERK1/2 phosphorylation in a G q inhibitor-sensitive manner, while BNGR-A15 was activated by CCHamide-1, thus leading to intracellular accumulation of cAMP, Ca2+ mobilization, and ERK1/2 phosphorylation in a G s and G q inhibitor-sensitive manner. Based on these findings, we designated the receptors BNGR-A15 and -A14 as Bommo -CCHaR-1 and -2, respectively. In addition, our results showed that CCHamides are considered to require intrachain disulfide bonds to activate their respective receptor in the physiological concentration range. Moreover, quantitative RT-PCR analysis revealed that CCHamide-1 is more likely to serve as a brain-gut peptide to regulate feeding behavior and growth through BNGR-A15, whereas the CCHamide-2 signaling system might play an important role in the control of multiple physiological processes. Our findings provide in-depth information on CCHamide-1 and -2-mediated signaling, facilitating further elucidation of their endocrinological roles in the regulation of fundamental physiological processes. Image 1 • Bombyx CCHamide-1 and CCHamide-2 are specific endogenous ligands for BNGR-A15 and BNGR-A14, respectively. • BNGR-A15 dually couples to G s - and G q -dependent pathways, while BNGR-A14 activates G q -dependent cascades • A disulfide bond is critical for CCHamides to activate their respective receptor in the physiological concentration range. • BNGR-A14 might play multiple physiological roles, whereas BNGR-A15 is likely to function as a brain-gut peptide. [ABSTRACT FROM AUTHOR]