Distant hybridization serves as a crucial method for germplasm innovation and variety improvement in ornamental plants; however, hybridization barriers hinder the creation of new varieties. Michelia compressa (Maxim.) Sarg., an evergreen tree belonging to the Magnolia (Magnoliaceae), is highly regarded for its exceptional ornamental qualities and resilience. In the case of intergeneric hybridization in M. compressa, pre-fertilization barriers complicate the acquisition of hybrid progeny, although the specific mechanisms underlying this phenomenon remain unclear. This study employed metabolomics, single-molecule real-time sequencing technology, and Illumina RNA sequencing to identify key metabolites and regulatory genes responsible for the observed affinity differences in interspecific and intergeneric hybridization of M. compressa. Functional validation was conducted on the key gene pectin methylesterase (PME), specifically the McoPME4 gene. Results indicated that double fertilization was successfully completed in interspecific hybridization at 4 days after pollination, while intergeneric hybridization faced challenges in achieving the same within the same timeframe. Metabolomic analysis of the M. compressa gynoecium following pollination revealed 1520 differentially accumulated metabolites. Furthermore, transcriptomic analysis identified 901 differentially expressed genes. Multi-omics analysis confirmed McoPME4 as a pivotal gene contributing to the interspecific hybridization in M. compressa × Michelia maudiae. The validation through genetic engineering demonstrated that the use of antisense oligonucleotides targeting McoPME4 significantly inhibited pollen tube growth. Conversely, the prokaryotic expression of McoPME4 was found to accelerate the growth rates of pollen tubes. Notably, in the Arabidopsis thaliana phenotype that overexpresses McoPME4, a marked enhancement in fertility was observed. In summary, these findings offer valuable insights into the mechanisms underlying the barriers to intergeneric hybridization in M. compressa.

Michelia compressa, a member of the Magnoliaceae family, is an evergreen tree of considerable significance in both landscape gardening and industrial production. However, during its introduction to northern subtropical regions in China, this species often suffers from frost damage, which limits its widespread application. The utilization of housekeeping genes is essential when performing gene family analyses under abiotic stress conditions. Additionally, auxin response factor (ARF) transcription factors (TF) play a crucial role in plant responses to abiotic stresses; however, their specific function in cold stress responses within M. compressa has not been systematically investigated. Ten housekeeping genes were selected from transcriptome data for evaluation using quantitative real-time PCR (qRT-PCR). The optimal housekeeping gene identified through screening was used for verification of gene family analysis. Additionally, key genes underwent functional validation. Analysis conducted with GeNorm, NormFinder, and BestKeeper identified 28S as the optimal reference gene for M. compressa under cold stress. Furthermore, an analysis of the ARF gene family using full-length transcriptome data revealed a total of 48 McoARF genes, which clustered into three groups alongside the Arabidopsis thaliana ARFs. Among these, eight selected McoARF genes exhibited significantly elevated expression levels in leaves under cold stress and demonstrated tissue specificity. Functional validation revealed that transgenic plants overexpressing McoARF13 displayed elevated levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), and malondialdehyde (MDA), as well as increased activities of peroxidase (POD) and superoxide dismutase (SOD) in leaves under cold stress. This study represents the inaugural screening of housekeeping genes in M. compressa under cold stress conditions, accompanied by an analysis of the ARF gene family. The functional validation of McoARF13 was successfully conducted, offering valuable insights into the molecular mechanisms that underlie cold stress response in M. compressa.

Hibiscus hamabo Sieb. et Zucc., a typical halophyte species, holds great potential for use in saline-alkali land development and serves as an important material for studying the molecular mechanisms of transcriptional regulation of salt stress tolerance in woody plants. Plant stress responses, including salt tolerance, are significantly influenced by NAC proteins, which are transcription factors unique to plants. Building on previous studies, we used transcriptome sequencing in conjunction with gene silencing to identify important downstream genes regulated by HhNAC54. Furthermore, bimolecular fluorescence complementation (BiFC) and yeast hybrid assays were used to confirm the interaction between HhNAC54 and HhMYB73. Phenotypic identification of gene-silenced H. hamabo revealed that HhNAC54 had a positive regulatory function in salt tolerance. Physiological indicator assessment and transcriptomic data suggested that HhNAC54 may regulate downstream genes related to stress-responsive metabolic pathways, antioxidant defense and other processes. A total of 34 interacting proteins including MYB transcription factors, F-box/kelch-repeat protein, metallothionein-like protein, IQ-DOMAIN 14 protein, were screened from the cDNA library of salt treated Hibiscus hamabo Sieb. et Zucc. seedlings using yeast two-hybrid technology. In vivo verification via BiFC confirmed that the HhMYB73 protein, whose expression was induced under salt stress, interacts with HhNAC54. Collectively, these findings indicated that HhNAC54 may enhance salt tolerance by regulating metabolic and redox pathways while interacting with HhMYB73 to coordinate transcriptional responses under stress. This study established a theoretical basis for a more thorough comprehension of salt tolerance in H. hamabo and offered HhNAC54 and HhMYB73 as promising molecular targets for breeding or genetic engineering strategies aimed at improving salt tolerance in Hibiscus and potentially other woody crops. HhNAC54 is identified as a key salt-tolerance regulator in Hibiscus hamabo, through the transcriptional activation of oxidoreductase and other genes, as well as interaction with salt-induced protein HhMYB73.

Hibiscus hamabo Sieb. et Zucc. (H. hamabo) is a semi-mangrove plant with excellent stress tolerance that plays a crucial role in the ecological restoration of saline and alkaline areas. It is an ideal candidate species for studying the mechanisms involved in stress tolerance. Although the MYB gene family has preliminarily been characterized in H. hamabo, the specific functions and action mechanisms of the R2R3-MYB genes in this species have not fully been elucidated. In this study, 190 R2R3-MYB genes were identified at the genomic level using bioinformatics methods. The genes were divided into 26 subgroups based on their evolutionary relationships and found to be distributed randomly on 46 chromosomes. RNA sequencing data and subsequent real-time quantitative PCR analysis of 12 differentially expressed R2R3-HhMYB genes showed HhMYB111r to be highly expressed under various abiotic stress conditions. Self-activation and subcellular localization results showed that the intact HhMYB111r had strong self-activation activity and located in both the nucleus and cytoplasm. Overexpression in Arabidopsis significantly improved salt tolerance, and silencing HhMYB111r reduced the tolerance of H. hamabo to salt stress, indicating that HhMYB111r positively regulates the salt stress response. In this first analysis of the R2R3-MYB gene family in H. hamabo, we identified a key salt stress response gene, HhMYB111r, enriching the understanding of MYB function and laying a foundation for exploring the abiotic stress response of plants.

Taxodium hybrid 'Zhongshanshan 406' (T. mucronatum♀ × T. distichum♂) is an excellent clone from the interspecific hybridization of Taxodium, which has a remarkable flooding tolerance level. The key energy supply gene in the glycolysis pathway of T. hybrid 'Zhongshanshan 406', alcohol dehydrogenase 1 (ThADH1) gene, plays an important role in the process of resisting flooding stress. Here, a cDNA library of T. hybrid 'Zhongshanshan 406' under flooding stress was constructed and screened. Several proteins interacting with ThADH1 were identified using yeast two-hybrid methods. In particular, an ethylene transcription factor, RELATED TO APETALA2.1 (ThRAP2.1), was identified as the interaction partner of ThADH1 using bimolecular fluorescence complementation. Under long-term flooding stress of 0-50 days, the expression level of ThRAP2.1 in roots, stems, and leaves showed an upward trend. ThRAP2.1 overexpression in poplar improved the flooding tolerance, increased 1-aminocyclopropane-1-carboxylic acid (ACC) content, ACC synthase (ACS) and ADH enzyme activities, and the ThADH1 expression level under flooding stress. This is the first report on the interaction between two flooding-tolerance-related proteins in woody plants. Screening for ThADH1 interacting proteins and analyzing their flooding tolerance will provide new gene resources for the regulation of flooding tolerance in woody plants and a theoretical basis for further understanding the mechanism of flooding tolerance in Taxodium.

Copy number variations (CNVs) are structural variants consisting of duplications and deletions of DNA segments, which are known to play important roles in the genetics of complex traits in livestock species. However, CNV-based genome-wide association studies (GWAS) have remained unexplored in American mink. Therefore, the purpose of the current study was to investigate the association between CNVs and complex traits in American mink. A CNV-based GWAS was performed with the ParseCNV2 software program using deregressed estimated breeding values of 27 traits as pseudophenotypes, categorized into traits of growth and feed efficiency, reproduction, pelt quality, and Aleutian disease tests. The study identified a total of 10,137 CNVs (6968 duplications and 3169 deletions) using the Affymetrix Mink 70K single nucleotide polymorphism (SNP) array in 2986 American mink. The association analyses identified 250 CNV regions (CNVRs) associated with at least one of the studied traits. These CNVRs overlapped with a total of 320 potential candidate genes, and among them, several genes have been known to be related to the traits such as ARID1B, APPL1, TOX, and GPC5 (growth and feed efficiency traits); GRM1, RNASE10, WNT3, WNT3A, and WNT9B (reproduction traits); MYO10, and LIMS1 (pelt quality traits); and IFNGR2, APEX1, UBE3A, and STX11 (Aleutian disease tests). Overall, the results of the study provide potential candidate genes that may regulate economically important traits and therefore may be used as genetic markers in mink genomic breeding programs.

Cold exposure exerts negative effects on hippocampal nerve development in adolescent mice, but the underlying mechanisms are not fully understood. Given that ubiquitination is essential for neurodevelopmental processes, we attempted to investigate the effects of cold exposure on the hippocampus from the perspective of ubiquitination. By conducting a ubiquitinome analysis, we found that cold exposure caused changes in the ubiquitination levels of a variety of synaptic-associated proteins. We validated changes in postsynaptic density-95 (PSD-95) ubiquitination levels by immunoprecipitation, revealing reductions in both the K48 and K63 polyubiquitination levels of PSD-95. Golgi staining further demonstrated that cold exposure decreased the dendritic-spine density in the CA1 and CA3 regions of the hippocampus. Additionally, bioinformatics analysis revealed that differentially ubiquitinated proteins were enriched in the glycolytic, hypoxia-inducible factor-1 (HIF-1), and 5‘-monophosphate (AMP)-activated protein kinase (AMPK) pathways. Protein expression analysis confirmed that cold exposure activated the mammalian target of rapamycin (mTOR)/HIF-1α pathway. We also observed suppression of pyruvate kinase M2 (PKM2) protein levels and the pyruvate kinase (PK) activity induced by cold exposure. Regarding oxidative phosphorylation, a dramatic decrease in mitochondrial respiratory-complex I activity was observed, along with reduced gene expression of the key subunits NADH: ubiquinone oxidoreductase core subunit V1 (Ndufv1) and Ndufv2. In summary, cold exposure negatively affects hippocampal neurodevelopment and causes abnormalities in energy homeostasis within the hippocampus.

The conifer Taxodium hybrid ‘Zhongshanshan’ (T. hybrid ‘Zhongshanshan’) is characterized by rapid growth, strong stress resistance, and high ornamental value and has significant potential for use in afforestation, landscaping, and wood production. The main method of propagating T. hybrid ‘Zhongshanshan’ is tender branch cutting, but the cutting rooting abilities of different T. hybrid ‘Zhongshanshan’ clones differ significantly. To explore the causes of rooting ability differences at a molecular level, we analyzed the transcriptome data of cutting base and root tissues of T. hybrid ‘Zhongshanshan 149’ with a rooting rate of less than 5% and T. hybrid ‘Zhongshanshan 118’ with rooting rate greater than 60%, at the developmental time points in this study. The results indicated that differentially expressed genes between the two clones were mainly associated with copper ion binding, peroxidase, and oxidoreductase activity, response to oxidative stress, phenylpropanoid and flavonoid biosynthesis, and plant hormone signal transduction, among others. The expression pattern of ThAP2 was different throughout the development of the adventitive roots of the two clone cuttings. Therefore, this gene was selected for further study. It was shown that ThAP2 was a nuclear-localized transcription factor and demonstrated a positive feedback effect on rooting in transgenic Nicotiana benthamiana cuttings. Thus, the results of this study explain the molecular mechanism of cutting rooting and provide candidate gene resources for developing genetic breeding strategies for optimizing superior clones of T. hybrid ‘Zhongshanshan’.

Background Aleutian disease (AD), caused by the Aleutian mink disease virus, is a significant health concern for mink, resulting in substantial economic losses for the mink industry. Although phenotypic selection of AD-resilient mink based on immune response and/or indicator traits is practiced by some mink farms, the genetic architecture of immune response and resilience to AD has not been widely explored. Thus, the objective of this study was to conduct the first genome-wide association studies (GWAS) analyses to identify genomic regions and genes associated with immune response and feed-intake-related resilience to AD in mink. Methods The genotypes and phenotypes, including two immune response traits measured by antigen-based enzyme-linked immunosorbent assay (ELISA-G) and iodine agglutination test (IAT) and two feed-intake-related resilience traits measured by the daily variation in feed intake (Varf) and proportion of off-feed days (DOF), of 1,411 mink from an AD-positive farm was used in this study. The de-regressed breeding values were derived from the estimated breeding values for each trait and utilized as pseudo-phenotypes in the analyses. Results A total of 17, eight, and seven significant (false-discovery-rate-adjusted-p-value (q) <0.01) single nucleotide polymorphisms (SNP) were detected to be associated with ELISA-G, IAT, and DOF, respectively, but no significant SNP was detected for Varf. A total of 141 genes were annotated from the significant SNPs for ELISA-G, and three of them, MPIG6B , RUNX2 , and C4A , might have important roles in immune-mediated responses to AD. Two ( TNFRSF11A and C4A ) of the 44 genes annotated in IAT were found to be involved in the immune system process. In addition, 42 genes were annotated in DOF, and two of them, ADCY7 and CNDP2 , were related to feed intake or appetite. A total of five significant (q<0.05) overrepresented gene ontology enrichment terms, which play important roles in the adaptive immune response or complement system, were detected for ELISA-G. Conclusions The significant SNPs and genes detected in this study help provide a better understanding of the genetic architecture underlying the immune response and resilience of mink to AD and the potential for improving the resilience of mink to AD using marker-assisted/genomic selection.

The genus Michelia encompasses important plants for landscaping and timber, with a wide global distribution. However, the genetic interrelations among species within the genus are not well understood. This study aims to clarify the genetic connections between Michelia compressa (Maxim.) Sarg. (Magnoliaceae) and other species in the genus to probe the potential improvement by interspecific hybridization. The work progresses in three phases: understanding M. compressa’s genetic architecture and its relevance to other Michelia species, identifying natural hybrids among progeny, and developing novel varieties through hybridization. First, the genome from M. compressa was analyzed to confirm its genetic background. The result shows it had 17 pairs of metacentric and 2 pairs of submetacentric chromosomes (2n = 2x = 38, 34m + 4sm), belonging to Stebbins type 2B, which was consistent with the Michelia uniform karyotype formula. Second, transcriptomic data were used to design ten pairs of simple sequence repeat (SSR) primers. The set of ten SSR primers exhibited a high level of polymorphism and were found to be efficient for genotyping. The average number of alleles (Na) per locus was 14.6, with an average expected heterozygosity (He) of 0.860, observed heterozygosity (Ho) of 0.447, and polymorphic information content (PIC) of 0.847. These universal primers were then employed to determine genetic relationships among Michelia species and create SSR fingerprints for 20 Magnoliaceae species. The cluster analysis results revealed that Magnoliaceae was classified into three branches, while Michelia was classified into five branches. M. compressa exhibits a close phylogenetic relationship with both M. maudiae and M. cavaleriei var. platypetala. Third, according to the fingerprinting information, all 19 progeny from open-pollinated M. compressa, i.e., M. ‘Zhongshanhanxiao’, were confirmed to be true hybrids resulting from natural crosses. The putative progenitors of M. ‘Zhongshanhanxiao’ are believed to be M. maudiae and M. cavaleriei var. platypetala. M. compressa demonstrates a significant hybrid affinity with both M. maudiae and M. cavaleriei var. platypetala. The SSR primers developed were used to identify hybrids, particularly in the M. compressa × M. maudiae and M. compressa × M. cavaleriei var. platypetala combinations, where a substantial proportion of true hybrids were found. Further analysis suggests that the probable progenitors of M. ‘Zhongshanhanxiao’ are either M. maudiae or M. cavaleriei var. platypetala. This research yields significant insights into the genetic relationships of M. compressa, as well as the prospects for genetic enhancement via interspecific hybridization. Furthermore, it establishes a theoretical framework for conserving and innovating Magnoliaceae germplasm resources.

Aleutian disease (AD) brings tremendous financial losses to the mink industry. Selecting AD-resilient mink has been conducted to control AD. Such selections could have altered the patterns of genetic variation responding to selection pressures. This study aimed to identify selection signatures for immune response (IRE) and resilience to AD. A total of 1,411 mink from an AD-positive facility were used. For IRE, 264 animals were categorized according to the combined results of enzyme-linked immunosorbent assay (ELISA) and counterimmunoelectrophoresis (CIEP). For resilience, two grouping methods were used: 1) general resilience performance (GRP, n = 30) was evaluated based on the feed conversion ratio, Kleiber ratio, and pelt quality; and 2) female reproductive performance (FRP, n = 36) was measured based on the number of kits alive 24 h after birth. Detection methods were the pairwise fixation index, nucleotide diversity, and cross-population extended haplotype homozygosity. A total of 619, 569, and 526 SNPs were identified as candidates for IRE, GRP, and FRP, respectively. The annotated genes were involved in immune system process, growth, reproduction, and pigmentation. Two olfactory-related Gene Ontology (GO) terms were significant (q < 0.05) for all traits, suggesting the impact of AD on the sense of smell of infected mink. Differences in detected genes and GO terms among different color types for IRE indicated variations in immune response to AD among color types. The mitogen-activated protein kinase (MAPK) signaling pathway was significant (q < 0.05) for FRP, suggesting that AD may disrupt MAPK signaling and affect FRP. The findings of this research contribute to our knowledge of the genomic architecture and biological mechanisms underlying AD resilience in mink.

Hibiscus hamabo Siebold & Zuccarini is one of the few semi-mangrove plants in the genus Hibiscus that can survive in saline-alkali soil and flooded land, but the mechanism underlying its adaptation to salt soil remains unknown. Here, to uncover this unsolved mystery, we characterized the changes in the accumulation of specific metabolites under salt stress in H. hamabo by integrating physiological, metabolic, and transcriptomic data, and found that osmotic adjustment and abscisic acid (ABA) is highly associated with the salt stress response. Further, a weighted gene co-expression network analysis was performed on the root transcriptome data, which identified three key candidate transcription factors responsive to salt stress. Among them, the expression HhERF9 was significantly upregulated under salt stress and ABA treatment and was involved in regulating the expression of genes related to the salt stress response. Further research indicated that HhERF9 enhances the accumulation of proline and soluble sugars by regulating the expression of genes such as NHX2 and P5CS. These findings provide a reference for improving H. hamabo through targeted genetic engineering and lay a theoretical foundation for its future promotion and cultivation in saline-alkali areas.

The recent chromosome-based genome assembly and the newly developed 70K single nucleotide polymorphism (SNP) array for American mink (Neogale vison) facilitate the identification of genetic variants underlying complex traits in this species. The objective of this study was to evaluate the association between consensus runs of homozygosity (ROH) with growth and feed efficiency traits in American mink. A subsample of two mink populations (n = 2,986) were genotyped using the Affymetrix Mink 70K SNP array. The identified ROH segments were included simultaneously, concatenated into consensus regions, and the ROH-based association studies were carried out with linear mixed models considering a genomic relationship matrix for 11 growth and feed efficiency traits implemented in ASReml-R version 4. In total, 298,313 ROH were identified across all individuals, with an average length and coverage of 4.16 Mb and 414.8 Mb, respectively. After merging ROH segments, 196 consensus ROH regions were detected and used for genome-wide ROH-based association analysis. Thirteen consensus ROH regions were significantly (P < 0.01) associated with growth and feed efficiency traits. Several candidate genes within the significant regions are known for their involvement in growth and body size development, including MEF2A, ADAMTS17, POU3F2, and TYRO3. In addition, we found ten consensus ROH regions, defined as ROH islands, with frequencies over 80% of the population. These islands harbored 12 annotated genes, some of which were related to immune system processes such as DTX3L, PARP9, PARP14, CD86, and HCLS1. This is the first study to explore the associations between homozygous regions with growth and feed efficiency traits in American mink. Our findings shed the light on the effects of homozygosity in the mink genome on growth and feed efficiency traits, that can be utilized in developing a sustainable breeding program for mink.

The genome-wide analysis of runs of homozygosity (ROH) islands can be an effective strategy to detect the variants shared among the individuals of a population, and thereby to reveal important genomic regions for complex traits. The current study performed ROH analysis to characterize the genome-wide patterns of homozygosity, ROH islands, and the gene content of those candidate regions using whole-genome sequencing data of 100 American mink (Neogale vison). After sequence processing, variants were called using GATK and Samtools pipelines. After quality control, 8,373,854 bi-allelic variants identified by both pipelines remained for subsequent analysis. A total of 34,652 ROH segments were identified in all individuals, among which shorter segments (0.3–1 Mb) were abundant throughout the genome, approximately accounting for 84.39% of all ROH. We identified 63 ROH islands that harbored 156 annotated genes. The genes located in ROH islands were associated with fur quality (EDNRA, FGF2, FOXA2, SLC24A4, SLC24A3, PDE5A), body size/body weight (MYLK4, PRIM2, FABP2, BBS7, EYS, PHF3), immune capacity (IL2, PTP4A1, SEMA4C, CD274, JAK2, MAD2L1, CCNA2, TNIP3), and reproduction (ADAD1, KHDRBS2, INSL6, PGRMC2, LARP1B, HSPA4L, CAMK2D). Furthermore, Gene Ontology and KEGG pathway enrichment analyses revealed multiple significant terms (P ≤ 0.05), among which cGMP-PKG signaling pathway, regulation of actin cytoskeleton, and calcium signaling pathway were highlighted due to their functional roles in growth and fur characteristics. This is the first study to present ROH islands in American mink. The candidate genes from ROH islands and functional enrichment analysis suggest possible signatures of selection in response to the mink breeding targets, such as increased body length, reproductive performance and fur quality. These findings contribute to an understanding of genetic characteristics, and provide complementary information to assist with implementation of breeding strategies for genetic improvement in American mink.

The objective of this study was to identify potential genetic variants and positional candidate genes associated with growth and feed efficiency traits in American mink. Genome-wide association studies (GWAS) were performed using deregressed estimated breeding values of 1037-1872 individuals (as pseudophenotypes), genotyped with the Affymetrix Mink 70K single nucleotide polymorphism (SNP) array. A total of 42 SNPs located on 11 different chromosomes were significantly (false discovery rate < 0.01) associated with six growth and feed efficiency traits. Furthermore, 153 genes were identified within 1-Mb windows flanking these significant SNPs. Several positional candidate genes such as TUBB, CDKN1A, SRSF3, GPRC6A, RFX6, and KPNA5 were previously associated with feed efficiency and growth traits in other livestock species. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that these genes were involved in lipid metabolism, hormone signaling and regulation, and muscle development. To our knowledge, this is the first GWAS to identify genetic variants and biological mechanisms associated with growth and feed efficiency traits in American mink. These findings provide a biological foundation for improving these traits using genomic selection programs to select more efficient mink.

Large-scale genotyping at a low cost is crucial for molecular breeding of livestock. In this study, the Cattle110K capture chip was developed, based on the genotyping by target sequencing system. The chip panel included 112,180 single necleotide polymorphisms (SNPs), from potential functional regions screened by genome-wide associated study, BayesB, expression quantitative trait loci-mapping, ATAC-seq, and reported functional markers. All the SNPs on the panel were distributed evenly on the cattle genome, with more than 99% of the markers having a minor allele frequency greater than 0.05. Assessment results indicated that a total of 1.2 M high-quality SNPs were identified in the 110 K regions, averaging approximately 10 SNPs per target sequence. The genotype consistency for the repetitive samples using the Cattle110K liquid chip was 99.21% while the concordance between the Illumina BovineHD BeadChip and this chip averaged 98.17%. A significant association signal for slaughter weight and carcass length was identified on 37.3-41.5 Mb of chromosome 6, pinpointing the NCAPG-LCORL locus. This locus has previously been associated with meat and carcass traits in cattle. Additionally, novel candidate regions were identified around 3.4 Mb of chromosome 13 and 73.5 Mb of chromosome 8, significantly correlated with hip height and marbling score, respectively. We compared the accuracy of genomic estimated breeding values between the Illumina BovineHD BeadChip and this chip. The results demonstrated that the Cattle110K capture chip had a comparable ability in genomic prediction to the Illumina BovineHD BeadChip. Advances in using the cost-effective liquid capture chip are expected to accelerate the genetic progress of cattle in the coming years.

Taxodium hybrid 'Zhongshanshan' has been widely used as a timber tree in river network areas and coastal regions and is mainly propagated by cuttings. However, when trees age, their capacity to form adventitious roots becomes weaker. We successfully enhanced the rooting ability of shoots in T. hybrid 'Zhongshanshan 302' by their rejuvenation based on grafting. We recorded temporal variation in endogenous auxin, abscisic acid (ABA), gibberellins (GAs), trans-zeatin-riboside (TZR), soluble sugar and H2O2 after root induction. Auxin, soluble sugars and H2O2 levels were higher in rejuvenated shoots than in mature shoots, whereas the opposite was true for ABA and GAs. Notably, indole-3-acetic acid (IAA) and GA3 presented higher contents with more obvious differences in T. hybrid 'Zhongshanshan 302' rejuvenated shoots vs. mature shoots compared with other kinds of auxin and GAs. The evident improvement in the rooting ability of rejuvenated shoots after grafting likely resulted from the differential regulation of plant hormones, carbohydrates and redox signaling. In addition to the physiological basis of improved rooting ability by grafting, this study provided a theoretical basis for the optimization of subsequent propagation techniques in T. hybrid 'Zhongshanshan' and potentially other Taxodium spp.

Heavy metal pollution of soil has become a serious global concern in recent years. In particular, cadmium (Cd) contamination is a ubiquitous environmental problem among heavy metals. Iris lactea var. chinensis is a perennial herb with significant ecological and industrial value. It is known for its good cadmium tolerance and cadmium enrichment capabilities; thus, it is considered an important plant for the restoration of cadmium-contaminated soil. Previous studies have shown that the cysteine-rich gene, IlCDT1 isolated from I. lactea conferred tolerance to Cd stress in yeast and Arabidopsis thaliana. However, the molecular mechanism of its regulation is poorly understood to date. In the current study, we screened and identified the transcription factor IlNF-YC6 that regulates IlCDT1 using yeast one-hybrid assay (Y1H). Overexpression of IlNF-YC6 conferred a significant tolerance to Cd stress in A. thaliana. Furthermore, the detection of physiological markers and transcriptome analysis revealed that IlNF-YC6 might increase plant tolerance to Cd stress primarily by improving plant detoxification ability and antioxidant capacity. Overall, our study would provide a genetic resource for candidate gene selection that might enhance plant tolerance to Cd contamination in soil or groundwater and subsequently lowering Cd absorption in the future.

Magnolia compressa Zhongshanhanxiao, a new Magnolia compressa (Maxim.) Sarg. cultivar, is described and illustrated in this paper. The leaves and flower of M. compressa ‘Zhongshanhanxiao’ were similar to M. compressa (Maxim.) Sarg., but differed from the latter by their larger sizes. The leaf lengths and widths of the new cultivar were 7 to 15 cm and 3 to 7 cm, respectively [the leaf lengths and widths of M. compressa (Maxim.) Sarg. were 5 to 7 cm and 2 to 3 cm, respectively], and the perianth lengths and widths were 4 to 7 cm and 1 to 4 cm, respectively [the perianth lengths and widths of M. compressa (Maxim.) Sarg. were 1.2 to 1.5 cm long and 0.3 to 0.5 cm wide]. In addition to the morphological differences, the new cultivar had a faster growth rate and the first flowering time was the third year after planting, whereas M. compressa (Maxim.) Sarg. took longer to first flower. The flowering period of this new cultivar was from February to March and the fruiting period was from October to November.