Explore the vast range of titles available.

Sex chromosomes evolved from autosomes many times across the eukaryote phylogeny. Several models have been proposed to explain this transition, some involving male and female sterility mutations linked in a region of suppressed recombination between X and Y (or Z / W , U / V ) chromosomes. Comparative and experimental analysis of a reference genome assembly for a double haploid YY male garden asparagus ( Asparagus officinalis L.) individual implicates separate but linked genes as responsible for sex determination. Dioecy has evolved recently within Asparagus and sex chromosomes are cytogenetically identical with the Y , harboring a megabase segment that is missing from the X . We show that deletion of this entire region results in a male-to-female conversion, whereas loss of a single suppressor of female development drives male-to-hermaphrodite conversion. A single copy anther-specific gene with a male sterile Arabidopsis knockout phenotype is also in the Y- specific region, supporting a two-gene model for sex chromosome evolution. Several models have been proposed to explain the emergence of sex chromosomes. Here, through comparative genomics and mutant analysis, Harkess et al. show that linked but separate genes on the Y chromosome are responsible for sex determination in Asparagus , supporting a two-gene model for sex chromosome evolution.

Sex chromosomes have evolved independently in phylogenetically diverse flowering plant lineages. The genes governing sex determination in dioecious species remain unknown, but theory predicts that the linkage of genes influencing male and female function will spur the origin and early evolution of sex chromosomes. For example, in an XY system, the origin of an active Y may be spurred by the linkage of female suppressing and male promoting genes. Garden asparagus (Asparagus officinalis) serves as a model for plant sex chromosome evolution, given that it has recently evolved an XX/XY sex chromosome system. In order to elucidate the molecular basis of gender differences and sex determination, we used RNA-sequencing (RNA-Seq) to identify differentially expressed genes between female (XX), male (XY) and supermale (YY) individuals. We identified 570 differentially expressed genes, and showed that significantly more genes exhibited male-biased than female-biased expression in garden asparagus. In the context of anther development, we identified genes involved in pollen microspore and tapetum development that were specifically expressed in males and supermales. Comparative analysis of genes in the Arabidopsis thaliana, Zea mays and Oryza sativa anther development pathways shows that anther sterility in females probably occurs through interruption of tapetum development before microspore meiosis.

A novel form of fructan exohydrolase was identified from asparagus, which is able to hydrolyze both inulin and inulin neoseries type fructans, and is implicated in remobilization of root fructan reserves to support the growth of emerging asparagus spears. Abstract Asparagus (Asparagus officinalis L.) accumulates inulin- and inulin neoseries-type fructans. Fructose released by the hydrolysis of fructans is an energy source for emerging asparagus spears. Plant fructans are hydrolyzed by fructan exohydrolases (FEHs), whose presence in asparagus has not yet been fully characterized. Here, we describe for the first time the purification and characterization of an FEH from asparagus, and the functional analysis of its gene. The purified enzyme was predicted to exist as a dimer (approximately 130 kDa) consisting of two polypeptides with a molecular mass of approximately 68 kDa. N-terminal sequences of the purified enzyme were matched with the amino acid sequences of aoeh4a and aoeh4b cDNAs isolated from asparagus (cv. Gijnlim and Taihouwase). Native enzymes obtained from asparagus roots and recombinant enzymes produced by Pichia pastoris showed fructan 1-exohydrolase (1-FEH) activity via the hydrolysis of inulin-type fructan. Unlike other 1-FEHs, these enzymes showed minimal hydrolysis of 1-kestose but efficiently hydrolyzed neokestose. Therefore, the enzyme was termed 6G&1-FEH. Gene expression studies in asparagus roots showed that aoeh4 increased during root storage at 2 °C and spear harvesting. These findings suggest that 6G&1-FEH may be involved in fructan hydrolysis in asparagus roots to provide an energy source for emerging asparagus spears.

Garden asparagus ( Asparagus officinali s L.), a dioecious perennial crop, is highly valued for its nutritional and medicinal properties. The high similarity among cultivars and abundant intracultivar variation pose challenges to conventional cultivar identification methods. Leveraging the conserved parental genotype of ‘clone hybrid’ (CH) cultivars, this study employed a single-plant sampling strategy in which 20 individuals per cultivar were analysed to capture intracultivar variation. An innovative approach was further introduced for constructing a fingerprint database based on parental genotype data, which were reverse-inferred following Mendelian inheritance principles. Fifty EST-SSR markers, with an average polymorphism information content (PIC) of 0.6344, were selected to evaluate the genetic relationships among 62 cultivars. These cultivars were divided into three subgroups, revealing limited correlationt with their geographical origins and indicating their intricate genetic backgrounds. Furthermore, a core set of 7 EST-SSR markers effectively distinguished all cultivars except ‘Huamiao’ and ‘C 5 -115’, which showed high similarity, suggesting potential synonymy. Validation with three identified cultivars and two novel hybrid combinations further confirmed the stability and accuracy of this fingerprint database. This study not only offers a reliable and practical tool for identifying the authenticity and purity of asparagus seeds but also provides a valuable foundation for efficient breeding programs.

Background Drought is a leading environmental factor affecting plant growth. To explore the drought tolerance mechanism of asparagus, this study analyzed the responses of two asparagus varieties, namely, ‘Jilv3’ (drought tolerant) and ‘Pacific Early’ (drought sensitive), to drought stress using metabolomics and transcriptomics. Results In total, 2,567 and 7,187 differentially expressed genes (DEGs) were identified in ‘Pacific Early’ and ‘Jilv3’, respectively, by comparing the transcriptome expression patterns between the normal watering treatment and the drought stress treatment. These DEGs were significantly enriched in the amino acid biosynthesis, carbon metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction pathways. In ‘Jilv3’, DEGs were also enriched in the following energy metabolism-related pathways: citrate cycle (TCA cycle), glycolysis/gluconeogenesis, and pyruvate metabolism. This study also identified 112 and 254 differentially accumulated metabolites (DAMs) in ‘Pacific Early’ and ‘Jilv3’ under drought stress compared with normal watering, respectively. The amino acid, flavonoid, organic acid, and soluble sugar contents were more significantly enhanced in ‘Jilv3’ than in ‘Pacific Early’. According to the metabolome and transcriptome analysis, in ‘Jilv3’, the energy supply of the TCA cycle was improved, and flavonoid biosynthesis increased. As a result, its adaptability to drought stress improved. Conclusions These findings help to better reveal the molecular mechanism underlying how asparagus responds to drought stress and improve researchers’ ability to screen drought-tolerant asparagus varieties as well as breed new varieties.

Background The Aux/IAA gene family encodes proteins that are central to auxin signaling and plant growth regulation. While Asparagus officinalis is a globally cultivated crop valued for its edible shoots, medicinal uses, and economic significance, the specific regulatory mechanisms and stress-responsive functions of Aux/IAA genes in this species remain largely uncharacterized. Previous studies have demonstrated Aux/IAA involvement in abiotic stress responses, but their roles in A. officinalis have not been systematically investigated. This study fills this gap by identifying candidate Aux/IAA genes in A. officinalis and characterizing their expression dynamics under salt stress, providing insights into their potential contributions to stress resilience. Results A comprehensive genome-wide analysis was conducted, revealing 17 Aux/IAA genes in A. officinalis . The results revealed that the AoIAA proteins featured a conserved Aux/IAA domain while demonstrating variability in their protein motif composition. Employing comparative genomics and evolutionary analyses, we classified the Aux/IAA genes into two major groups. Gene duplication analysis further identified two pairs of WGD/segmental duplication genes. The study of cis -regulatory elements in AoIAA gene promoters identified links to phytohormone signaling and abiotic stress responses. Additionally, the expression patterns of AoIAAs in A. officinalis differed among various tissues. The AoIAAs responded differently to salt treatment, notably with AoIAA1 , AoIAA10 , and AoIAA12 expression increasing alongside higher salt concentrations, highlighting their role in salt stress adaptation. Conclusion This study systematically characterized the Aux/IAA gene family in A. officinalis , highlighting their diversity and revealing structural and regulatory features. The findings provide a foundational resource for elucidating the biological functions and molecular mechanisms underlying Aux/IAA -mediated responses to salt stress and growth regulation in this species.

Abstract The relatively young and repeated evolutionary origins of dioecy (separate sexes) in flowering plants enables the investigation of molecular dynamics occurring at the earliest stages of sex chromosome evolution. With two independently young origins of dioecy, Asparagus is a model genus for studying the genetics of sex-determination and sex chromosome evolution. Dioecy first evolved in Asparagus ∼3 to 4 million years ago (Ma) in the ancestor of a now widespread Eurasian clade including garden asparagus (Asparagus officinalis). A second origin occurred in a smaller, geographically restricted, Mediterranean Basin clade, including Asparagus horridus. New haplotype-resolved reference genomes for garden asparagus and A. horridus, elucidate contrasting first steps in the origin of the sex chromosomes of the Eurasian and Mediterranean Basin clade ancestors. Analysis of the A. horridus genome revealed an XY system derived from a different ancestral pair of autosomes with different sex-determining genes than have been characterized for garden asparagus. We estimate that proto-XY chromosomes evolved 1 to 2 Ma in the Mediterranean Basin clade, following a ∼2.1-megabase inversion that now distinguishes the X and Y chromosomes. Recombination suppression and LTR retrotransposon accumulation drove the expansion of the male-specific region on the Y (MSY) that reaches ∼9.6-megabases in A. horridus. The garden asparagus genome revealed an MSY spanning ∼1.9-megabases. A segmental duplication and neofunctionalization of one duplicated gene (SOFF) drove the origin of dioecy in the Eurasian clade. These findings support previous inference based on phylogeographic analysis revealing two recent origins of dioecy in Asparagus and establish the genus as a model for investigating sex chromosome evolution.

Asparagus species are widely used for medicinal, horticultural, and culinary purposes. Complete chloroplast DNA (cpDNA) genomes of three Asparagus specimens collected in Hong Kong-A. aethiopicus, A. densiflorus 'Myers', and A. cochinchinensis-were de novo assembled using Illumina sequencing. Their sizes ranged from 157,069 to 157,319 bp, with a total guanine-cytosine content of 37.5%. Structurally, a large single copy (84,598-85,350 bp) and a small single copy (18,677-18,685 bp) were separated by a pair of inverted repeats (26,518-26,573 bp). In total, 136 genes were annotated for A. aethiopicus and A. densiflorus 'Myers'; these included 90 mRNA, 38 tRNA, and 8 rRNA genes. Further, 132 genes, including 87 mRNA, 37 tRNA, and 8 rRNA genes, were annotated for A. cochinchinensis. For comparative and phylogenetic analysis, we included NCBI data for four congenerics, A. setaceus, A. racemosus, A. schoberioides, and A. officinalis. The gene content, order, and genome structure were relatively conserved among the genomes studied. There were similarities in simple sequence repeats in terms of repeat type, sequence complementarity, and cpDNA partition distribution. A. densiflorus 'Myers' had distinctive long sequence repeats in terms of their quantity, type, and length-interval frequency. Divergence hotspots, with nucleotide diversity (Pi) [greater than or equal to] 0.015, were identified in five genomic regions: accD-psaI, ccsA, trnS-trnG, ycf1, and ndhC-trnV. Here, we summarise the historical changes in the generic subdivision of Asparagus. Our phylogenetic analysis, which also elucidates the nomenclatural complexity of A. aethiopicus and A. densiflorus 'Myers', further supports their close phylogenetic relationship. The findings are consistent with prior generic subdivisions, except for the placement of A. racemosus, which requires further study. These de novo assembled cpDNA genomes contribute valuable genomic resources and help to elucidate Asparagus taxonomy.

Asparagus species are widely used for medicinal, horticultural, and culinary purposes. Complete chloroplast DNA (cpDNA) genomes of three Asparagus specimens collected in Hong Kong-A. aethiopicus, A. densiflorus 'Myers', and A. cochinchinensis-were de novo assembled using Illumina sequencing. Their sizes ranged from 157,069 to 157,319 bp, with a total guanine-cytosine content of 37.5%. Structurally, a large single copy (84,598-85,350 bp) and a small single copy (18,677-18,685 bp) were separated by a pair of inverted repeats (26,518-26,573 bp). In total, 136 genes were annotated for A. aethiopicus and A. densiflorus 'Myers'; these included 90 mRNA, 38 tRNA, and 8 rRNA genes. Further, 132 genes, including 87 mRNA, 37 tRNA, and 8 rRNA genes, were annotated for A. cochinchinensis. For comparative and phylogenetic analysis, we included NCBI data for four congenerics, A. setaceus, A. racemosus, A. schoberioides, and A. officinalis. The gene content, order, and genome structure were relatively conserved among the genomes studied. There were similarities in simple sequence repeats in terms of repeat type, sequence complementarity, and cpDNA partition distribution. A. densiflorus 'Myers' had distinctive long sequence repeats in terms of their quantity, type, and length-interval frequency. Divergence hotspots, with nucleotide diversity (Pi) [greater than or equal to] 0.015, were identified in five genomic regions: accD-psaI, ccsA, trnS-trnG, ycf1, and ndhC-trnV. Here, we summarise the historical changes in the generic subdivision of Asparagus. Our phylogenetic analysis, which also elucidates the nomenclatural complexity of A. aethiopicus and A. densiflorus 'Myers', further supports their close phylogenetic relationship. The findings are consistent with prior generic subdivisions, except for the placement of A. racemosus, which requires further study. These de novo assembled cpDNA genomes contribute valuable genomic resources and help to elucidate Asparagus taxonomy.

Ultraviolet B (UVB) radiation severely damages human skin by causing DNA damage, oxidative stress, and collagen degradation. This study explored the photoprotective properties of Asparagus cochinchinensis extracts fermented with endophytic fungus Aspergillus aculeatus TD103. Compared to the unfermented control, TD103-fermented A. cochinchinensis demonstrated stronger radical scavenging and ferric ion reduction abilities in vivo, significantly reduced intracellular reactive oxygen species (ROS) and increased the antioxidant enzymes including heme oxygenase-1 (HO-1), superoxide dismutase (SOD), and catalase (CAT) in UVB-induced HaCaT cells. It also downregulated the expression of the AP-1 and MMP genes, reduced the content of matrix metalloproteinase (MMP-1) and increased type I procollagen amino-terminal propeptide (PINP) levels in UVB-induced HaCaT cells. Non-targeted metabolomics and HPLC quantification revealed that elevated sarsasapogenin content may critically contribute to enhanced photoprotective capacity in Asparagus cochinchinensis . The safety assessment of fungus TD103 revealed that this strain was not drug resistant and did not produce mycotoxins, thereby indicating its safety for application. Eye irritation tests demonstrated the safety profile of the fermented extract, indicating negligible irritant potential. The TD103-mediated fermentation markedly potentiated the photoprotective capacity of A. cochinchinensis , ​providing a viable biotechnological platform for sustainable cosmeceutical development targeting UV-induced skin damage.