Search Results (22)

Heterosis is a landmark innovation in modern agriculture, which has been widely exploited to boost crop productivity. As a staple food for over half of the global population, rice depends heavily on heterosis for yield improvement. Notably, hybrid rice has made remarkable contributions to global food security over the past several decades. Male sterility serves as the fundamental basis for efficient hybrid rice breeding, with cytoplasmic male sterility (CMS) and genic male sterility (GMS) as the core systems employed in practical production. CMS, induced by mitochondrial genes, can be restored to fertility by nuclear restorer genes, thereby forming the essential genetic basis for the three-line hybrid rice system. GMS, mainly regulated by the nuclear genome, includes dominant and recessive nuclear sterility. Specifically, recessive environment-sensitive genic male sterility (EGMS) has facilitated the development of the two-line hybrid rice system for commercial hybrid seed production. The third-generation hybrid rice technology (TGHRT) is a transgenic approach developed for propagating stable recessive GMS lines. This review comprehensively summarizes the latest advances in rice male sterility systems, focusing on their genetic classification, origin, and molecular mechanisms. It further analyzes their application status, inherent limitations, future research directions, and development trends in hybrid rice production, aiming to deepen our understanding of the innovation and optimization of hybrid rice breeding technologies. Full article

Background/Objectives: Larix decidua has been used in traditional medicine for the treatment of various inflammatory conditions. Although their use has been recognized in alternative medicine, the scientific documentation of the antioxidant and anti-inflammatory potential of ethanolic extracts from its needles remains insufficiently characterized. The present study aimed to characterize the phytochemical profile of the ethanolic L. decidua extract, evaluate its in vitro antioxidant capacity, and investigate its therapeutic and prophylactic effects on oxidative–nitrosative stress and inflammation. Methods: L. decidua needles were extracted using a modified Squibb repercolation method. Polyphenol and flavonoid content were quantified, and individual phenols were identified by HPLC-DAD-ESI⁺. The in vitro antioxidant activity was evaluated using DPPH, FRAP, H₂O₂, and NO scavenging assays. The therapeutic and prophylactic in vivo potential was evaluated in a model of acute inflammation induced with turpentine in male Wistar rats. Serum oxidative markers (TOS, TAC, OSI, MDA, AOPP, 8-OHdG, NO, 3-NT, SH) and inflammatory markers (NFκB-p65, IL-1β, IL-18) were quantified. Results: The extract contained high levels of flavonols and hydroxybenzoic acids; kaempferol glycosides and catechin were the dominant constituents. In vitro, the extract exhibited radical scavenging activities. In vivo, L. decidua attenuated oxidative and nitrosative stress, restored antioxidant defense, and reduced NFκB-p65, IL-1β, and IL-18 levels in a concentration-dependent manner. The L100 concentration most closely approximated the values produced by Trolox and diclofenac. Conclusions: The ethanolic Larix decidua needle extract exerted antioxidant and anti-inflammatory effects in a rat model of acute sterile inflammation, attenuating systemic oxidative–nitrosative stress and pro-inflammatory mediators in a concentration-dependent manner. These preclinical findings support further investigation of standardized L. decidua needle preparations as polyphenol-rich nutraceutical/functional ingredient candidates within preventive and adjunct nutrition strategies targeting oxidative stress-driven inflammation. Full article

The combination of Chinsurah Boro II (BT)-type cytoplasmic male sterility (CMS) and Rf1, the main fertility restorer gene (Rf) for CMS-BT, has been extensively utilized for the production of three-line commercial japonica hybrid seeds. The identification of new Rf genes holds significance for the breeding of BT-type restorer lines, aiming to enhance the heterosis level of BT-type japonica hybrids. In the present study, ‘02428’, a wide-compatibility japonica variety, was observed to partially restore fertility to BT-type CMS lines. Genetic analysis revealed that ‘02428’ carries a dominant Rf gene, Rf21(t), responsible for the fertility restoration of BT-type CMS lines. Leveraging bulked segregant analysis (BSA) resequencing technology and molecular markers, the Rf21(t) locus was identified, and mapped within a candidate interval of 6–12.5 Mb on chromosome 2. Using the iso-cytoplasmic restorer populations, Rf21(t) was ultimately mapped to an interval of approximately 77 kb, encompassing 12 predicted genes, including LOC_Os02g17360, encoding a PPR-domain-containing protein and LOC_Os02g17380 (Rf2), a cloned Rf for Lead-rice-type CMS. A comparative sequence analysis, gene expression profiling and gene knockout experiments confirmed that LOC_Os02g17360 and LOC_Os02g17380 are the most likely candidates of Rf21(t). Furthermore, Rf21(t) showed the dosage effect on the fertility restoration of BT-type CMS lines. This newly identified Rf21(t) represents a valuable genetic resource for the breeding of BT-type japonica restorer lines. Our findings offer practical insights for breeders interested in advancing BT-type japonica hybrid development. Full article

This exploratory study presents the first metagenomic assessment of the gut microbiome in domestic cats from Cali, Colombia. Fecal samples were collected from 10 healthy, sterilized domestic cats, aged 8 months to over 2 years, with variation in sex (7 females, 3 males), diet (processed or raw), and outdoor access (5 with, 5 without). Using 16S rRNA gene metabarcoding and pooled shotgun metagenomic sequencing, the study characterized the taxonomic composition and functional potential of the feline gut microbiome. Dominant phyla included Bacillota and Bacteroidota, with substantial inter-individual variation. Peptoclostridium was the most consistently abundant genus, while Megamonas and Megasphaera showed higher variability. Shotgun analysis detected antibiotic resistance genes (ErmG, ErmQ) and virulence factors (pfoA, plc, colA, nanJ, nagI) in Clostridium perfringens, highlighting potential zoonotic risk. The composition of the gut microbiota was influenced primarily by diet and outdoor access, while age and gender had more moderate effects. The study concludes that lifestyle and environmental factors play a key role in shaping the gut microbiome of domestic cats. We recommend further longitudinal and larger-scale studies to better understand the dynamics of feline microbiota and their implications for animal and public health within a One Health framework. Full article

Pyrus bretschneideri ‘Xinli No.7’, a progeny of Pyrus sinkiangensis ‘Korla Fragrant Pear’, is an early-maturing, high-quality pear (Pyrus spp.) cultivar. As a dominant variety in China’s pear-producing regions, it holds significant agricultural importance. Investigating its male sterility (MS) mechanisms is critical for hybrid breeding and large-scale cultivation. Integrated cytological, physiological, and transcriptomic analyses were conducted to compare dynamic differences between male sterility (MS, ‘Xinli No.7’) and male-fertile (MF, ‘Korla Fragrant Pear’) plants during anther development. Cytological observations revealed that, compared with ‘Korla Fragrant Pear’, the tapetum of ‘Xinli No.7’ exhibited delayed degradation and abnormal thickening during the uninucleate microspore stage. This pathological alteration compressed the microspores, ultimately leading to their abortion. Physiological assays demonstrated excessive reactive oxygen species (ROS) accumulation, lower proline content, higher malondialdehyde (MDA) levels, and reduced activities of antioxidant enzymes (peroxidase and catalase) in MS plants. Comparative transcriptomics identified 283 co-expressed differentially expressed genes (DEGs). Functional enrichment linked these DEGs to ROS-scavenging pathways: galactose metabolism, ascorbate and aldarate metabolism, arginine and proline metabolism, fatty acid degradation, pyruvate metabolism, and flavonoid biosynthesis. qRT-PCR validated the expression patterns of key DEGs in these pathways. A core transcriptome-mediated MS network was proposed, implicating accelerated ROS generation and dysregulated tapetal programmed cell death. These findings provide theoretical insights into the molecular mechanisms of male sterility in ‘Xinli No.7’, supporting future genetic and breeding applications. Full article

The essential oil (EO) of Schinus areira exhibits a chemical composition dominated by monoterpene and sesquiterpene hydrocarbons, with α-phellandrene, limonene, α-pinene, and p-cymene as major constituents. This study aimed to evaluate the effects of S. areira EO on the biology and behavior of the Mediterranean fruit fly, Ceratitis capitata, particularly its attraction to the EO and the impact on its reproductive behavior and survival. Females were attracted at the initial choice and the time spent in the arm of the Y-tube olfactometer with the EO was longer, while males were attracted at the final choice, indicating the attractive potential of S. areira EO for both sexes of C. capitata. Within the context of the sterile insect technique (SIT), the better performance of released sterile males allows more copulations with wild females in competition with wild males, increasing the efficacy of the SIT. Exposure of tsl sterile males to the EO did not enhance their sexual competitiveness and increased latency to initiate copulation, indicating potential adverse effects. In addition, in oviposition assays, only a low concentration of the EO stimulated egg-laying on treated substrates, possibly due to the absence of deterrent compounds such as linalool. Finally, the LD50 of the EO was <25 µg/fly for both females and males, at 72 h post-treatment. These findings highlight the potential of EOs as biopesticides that influence the behaviors of C. capitata and emphasize the need for further studies to optimize their application in integrated pest management strategies, including the SIT. Full article

Cytoplasmic male sterility (CMS) and dominant genic male sterility (DGMS) both result in the inability to produce or release functional pollen, making them pivotal systems in the hybridization breeding programs of Brassica crops such as cabbage (B. oleracea var. capitata). However, the underling molecular mechanisms are still largely unexplored. This study integrated transcriptomic and metabolomic analyses of cabbage DGMS line, Ogura CMS line, and the maintainer line to uncover the molecular mechanisms underlying these sterility types. The joint analysis predominantly identified significantly enriched pathways, including carbohydrate metabolism, flavonoid biosynthesis, and phenylpropanoid pathways between the MS lines and the maintainer. Especially, the CMS line exhibited a broader range of metabolic perturbations, with a total of 3556 significantly differentially expressed genes (DEGs) and 439 differentially accumulated metabolites (DAMs) detected, particularly in the vitamin B6 metabolism pathway, which showed significant alterations. Given the differences in the inactivation period of microspores in CMS and DGMS lines, we found that DEGs unique to DGMS and maintainer line, such as BoGRPs and BoLTPs, primarily regulate fertility development before the unicellular stage. The DEGs shared between CMS_vs_maintainer and DGMS_vs_maintainer mainly govern microspore development after release from the tetrad, such as BoHXK1 and BoIDH. Additionally, the DEGs unique to CMS_vs_maintainer may contribute to other damage in floral organs beyond male fertility, potentially leading to severe bud abortion, such as BoPNPO. These findings provide a comprehensive framework for understanding the molecular mechanisms of male sterility and offer valuable insights into future breeding strategies in cruciferous vegetables. Full article

Plutella xylostella (Linnaeus) mainly damages cruciferous crops and causes huge economic losses. Presently, chemical pesticides dominate its control, but prolonged use has led to the development of high resistance. In contrast, the sterile insect technique provides a preventive and control method to avoid the development of resistance. We discovered two genes related to the reproduction of Plutella xylostella and investigated the efficacy of combining irradiation with RNA interference for pest management. The results demonstrate that after injecting PxAKT and PxCDK5, there was a significant decrease of 28.06% and 25.64% in egg production, and a decrease of 19.09% and 15.35% in the hatching rate compared to the control. The ratio of eupyrene sperm bundles to apyrene sperm bundles also decreased. PxAKT and PxCDK5 were identified as pivotal genes influencing male reproductive processes. We established a dose-response relationship for irradiation (0–200 Gy and 200–400 Gy) and derived the irradiation dose equivalent to RNA interference targeting PxAKT and PxCDK5. Combining RNA interference with low-dose irradiation achieved a sub-sterile effect on Plutella xylostella, surpassing either irradiation or RNA interference alone. This study enhances our understanding of the genes associated with the reproduction of Plutella xylostella and proposes a novel approach for pest management by combining irradiation and RNA interference. Full article

Stem cell maintenance and differentiation can be regulated via the differential activity of transcription factors within stem cells and their progeny. For these factors to be active, they need to be transported from their site of synthesis in the cytoplasm into the nucleus. A tissue-specific requirement for factors involved in nuclear importation is a potential mechanism to regulate stem cell differentiation. We have undertaken a characterization of male sterile importin alpha 1 (Dα1) null alleles in Drosophila and found that Dα1 is required for maintaining germline stem cells (GSCs) in the testis niche. The loss of GSCs can be rescued by ectopic expression of Dα1 within the germline but the animals are still infertile, indicating a second role for Dα1 in spermatogenesis. Expression of a Dα1 dominant negative transgene in GSCs confirmed a functional requirement for Dα1 in GSC maintenance but expression of the transgene in differentiating spermatogonia did not exhibit a phenotype indicating a specific role for Dα1 within GSCs. Our data indicate that Dα1 is utilized as a regulatory protein within GSCs to facilitate nuclear importation of proteins that maintain the stem cell pool. Full article

Plant architecture is one of the key factors affecting maize yield formation and can be divided into secondary traits, such as plant height (PH), ear height (EH), and leaf number (LN). It is a viable approach for exploiting genetic resources to improve plant density. In this study, one natural panel of 226 inbred lines and 150 family lines derived from the offspring of T32 crossed with Qi319 were genotyped by using the MaizeSNP50 chip and the genotyping by sequence (GBS) method and phenotyped under three different environments. Based on the results, a genome-wide association study (GWAS) and linkage mapping were analyzed by using the MLM and ICIM models, respectively. The results showed that 120 QTNs (quantitative trait nucleotides) and 32 QTL (quantitative trait loci) related to plant architecture were identified, including four QTL and 40 QTNs of PH, eight QTL and 41 QTNs of EH, and 20 QTL and 39 QTNs of LN. One dominant QTL, qLN7-2, was identified in the Zhangye environment. Six QTNs were commonly identified to be related to PH, EH, and LN in different environments. The candidate gene analysis revealed that Zm00001d021574 was involved in regulating plant architecture traits through the autophagy pathway, and Zm00001d044730 was predicted to interact with the male sterility-related gene ms26. These results provide abundant genetic resources for improving maize plant architecture traits by using approaches to biological breeding. Full article

Flax is an economic crop with a long history. It is grown worldwide and is mainly used for edible oil, industry, and textiles. Here, we reported a high-quality genome assembly for “Neiya No. 9”, a popular variety widely grown in China. Combining PacBio long reads, Hi-C sequencing, and a genetic map reported previously, a genome assembly of 473.55 Mb was constructed, which covers ~94.7% of the flax genome. These sequences were anchored onto 15 chromosomes. The N50 lengths of the contig and scaffold were 0.91 Mb and 31.72 Mb, respectively. A total of 32,786 protein-coding genes were annotated, and 95.9% of complete BUSCOs were found. Through morphological and cytological observation, the male sterility of flax was considered dominant nuclear sterility. Through GWAS analysis, the gene LUSG00017705 (cysteine synthase gene) was found to be closest to the most significant SNP, and the expression level of this gene was significantly lower in male sterile plants than in fertile plants. Among the significant SNPs identified in the GWAS analysis, only two were located in the coding region, and these two SNPs caused changes in the protein encoded by LUSG00017565 (cysteine protease gene). It was speculated that these two genes may be related to male sterility in flax. This is the first time the molecular mechanism of male sterility in flax has been reported. The high-quality genome assembly and the male sterility genes revealed, provided a solid foundation for flax breeding. Full article

Doubled haploid (DH) technology is an efficient strategy for producing completely homozygous lines for breeding programs. Mutations in the MATRILINEAL (MTL) phospholipase trigger intraspecific haploid induction in cereals. Although an in vivo haploid induction system based on OsMTL-edited plants has been established in rice (Oryza sativa), DH technology is still limited by other factors, such as haploid identification, which is one of the essential steps required for DH technology. In the study, we addressed this technical challenge by integrating specific molecular and phenotypic markers into rice haploid inducers. We first generated large fragment insertion or deletion mutations within the OsMTL gene and designed a pair of primers flanking the mutational sites to be used as the specific and universal molecular markers between wild-type and Osmtl plants. Next, we screened for hairy leaf as a single dominant trait and integrated it into specific molecular marker-based haploid inducers using the cross and self-cross method. When crossing cytoplasmic male sterile lines with these haploid inducers, we utilized the specific InDel marker and hairy leaf phenotypic marker to identify putative haploids (or double haploids). These putative haploids were further confirmed through ploidy and phenotypic analysis, demonstrating the high efficiency of haploid identification using these markers. The haploid induction rate (HIR) of the developed specific molecular and phenotypic marker-based haploid inducers ranged from 3.7% to 12.5%. We have achieved successful integration of distinct molecular and phenotypic markers into rice haploid inducers. Our advanced marker-based system has significantly enhanced the accuracy of haploid identification, thereby expediting the adoption of DH technology in rice breeding. Full article

Rice is one of the most economically important staple food crops in the world. Soil salinization and drought seriously restrict sustainable rice production. Drought aggravates the degree of soil salinization, and, at the same time, increased soil salinity also inhibits water absorption, resulting in physiological drought stress. Salt tolerance in rice is a complex quantitative trait controlled by multiple genes. This review presents and discusses the recent research developments on salt stress impact on rice growth, rice salt tolerance mechanisms, the identification and selection of salt-tolerant rice resources, and strategies to improve rice salt tolerance. In recent years, the increased cultivation of water-saving and drought-resistance rice (WDR) has shown great application potential in alleviating the water resource crisis and ensuring food and ecological security. Here, we present an innovative germplasm selection strategy of salt-tolerant WDR, using a population that is developed by recurrent selection based on dominant genic male sterility. We aim to provide a reference for efficient genetic improvement and germplasm innovation of complex traits (drought and salt tolerance) that can be translated into breeding all economically important cereal crops. Full article

Hybridization between Cucumis species, including cultivated melon (C. melo), is hampered by Interspecific Reproductive Barriers (IRBs). However, the nature of IRBs in Cucumis is largely unknown. This study explores locations, timing, and contribution to reproductive isolation (RI) of pre- and post-zygotic IRBs in Cucumis. To do this, we assessed crossability among Cucumis African wild species and C. melo at the pre-zygotic level by visualizing pollen tubes under fluorescence microscopy and, post-zygotically, by evaluating fruit/seed set and F₁ hybrid fertility. Genetic distances among Cucumis species were inferred from Genotyping-by-Sequencing, and its correlation with RI stages was analyzed. Observed pre- and post-zygotic IRBs included pollen tube arrest, fruit set failure, and hybrid male sterility. Unilateral cross-incongruity/incompatibility (UCI) was detected in some hybridizations, and dominant gene action is suggested for pistil-side UCI in interspecific F₁ hybrids. Notably, the allotetraploid C. ficifolius was very fertile as a seed parent but infertile in all reciprocal crosses. Contribution to RI was found significant for both pre- and post-zygotic IRBs. Additionally, a significant positive correlation was detected between genetic distance and pre- and post-zygotic RI stages. Interestingly, UCI offers an accessible system to dissect the genetics of IRBs in Cucumis, which may facilitate the use of wild relatives in breeding. Full article

The Queensland fruit fly (Q-fly), Bactrocera tryoni (Froggatt) is a serious horticultural pest in Australia because it is highly invasive and destructive. Among all pest management practices, sterile insect techniques (SIT) and male annihilation techniques (MAT) are important control options for many tephritid fruit fly pests, including Q-fly. However, simultaneous applications of MAT and SIT require the wild males to be responsive to a lure while the released sterile males remain largely unresponsive. In this study, a series of artificial selection experiments was conducted to develop lines of Q-fly with different levels of response to the male-specific lure Cue-lure^® (CL). After only five cycles of artificial selections, lines of high responsiveness (HR) and low responsiveness (LR) males diverging significantly in their response to the lure were developed. In the field cage experiment, the number of trapped males in fruit fly traps was significantly lower in the LR line than both the HR line and the control which supports the laboratory results. However, when artificial selection was stopped at F5 and retested after two generations, the number of unresponsive males dropped drastically compared to the rate of response of wild flies. Because the selection can be conducted only on males, it would be difficult to eliminate the dominant responsive alleles in the system without continuous selection. Full article