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The plant B3 gene superfamily contains a large number of transcription factors playing a vital role in both vegetative growth and reproductive development in plants. Although several B3 genes have been well studied, molecular functions of the B3 genes in olive are largely unknown. In our study, a total of 200 B3 genes were identified in olive genome based on RNA-seq and comparative genomic analyses and further classified into five groups (i.e., REM, RAV, LAV, HSI, and ARF) based on phylogenetic analysis. Results of gene structure and motif composition analyses revealed diversified functions among these five groups of B3 genes. Results of genomic duplication and syntenic analyses indicated the gene expansion in the B3 genes. Results of gene expression based on both transcriptomics and relative expression revealed the tissue-biased expression patterns in B3 genes. The results of the comparative expression analysis of B3 genes between two olive cultivars with high and low oil contents identified several potential REM genes which may be involved in oil biosynthesis in olive. Based on the comprehensive characterization of the molecular structures and functions of B3 genes in olive genome, our study provided novel insights into the potential roles of B3 transcription factors in oil biosynthesis in olive and lays the groundwork for the functional explorations into this research field.

Seed storability (SS), also called seed longevity, is a valuable trait for seed banks and providing reliable crop seeds to farmers, which is usually negatively correlated to lipoxygenase (LOX) activity. In this study, the seed storability of 60 accessions of CIMMYT core wheat germplasm panel (CIMCOG) was investigated through artificial aging (AA) test, including three parameters relative germination potential (RGP), relative germination rate (RGR) and relative seedling vigor index (RVI). Significant positive relationships were observed among RGP, RGR and RVI. And the genotypes at three LOX activity related QTLs/genes QLpx.caas-4B, QLpx.caas-1AL and TaLOX-B1 were also identified with published trait-associated molecular markers. For QLpx.caas-4B, a total of five alleles were detected at the locus of Xgwm251, and one marker-trait association was identified for RVI. Four and two alleles were detected at the loci of QLpx.caas-1AL and TaLoxB1 that were significantly associated with RGP, RGR and RVI, respectively. A total of 9 haplotypes were detected at three lipoxygenase activity related gene loci, and the haplotype of three lipoxygenase loci showed a significant association with RGP, RGR and RVI. The haplotype of Xgwm251-125bp + Xwmc312-247bp + TaLox-B1b produced seeds with the best storability in the CIMCOG, which could benefit the breeding for wheat with good seed storability.

Members of the EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family play diverse roles in plant growth and development, including the guidance of inflorescence architecture and pedicel length. In this work, we identified and characterized the EFPL gene TaEPFL1 from the wheat pistillody mutant HTS-1. Sequence alignment and phylogenetic analysis indicated that TaEPFL1 belongs to the EPFL1 gene. Quantitative real-time RT-PCR analysis showed that the TaEPFL1 gene is expressed at an abnormally high level in pistillody stamens compared with that in pistils and stamens. Heterologous expression of the TaEPFL1 gene in Arabidopsis caused shortened filaments and pedicels and might reduce the level of AtACO2 gene expression. These results suggest that TaEPFL1 plays an important role in the development of stamen and that overexpression of TaEPFL1 results in abnormal stamens. We deduced that the overexpression of the TaEPFL1 gene may contribute to the homeotic transformation of stamens into pistils or pistil-like structures in wheat. These data offer insights into the molecular mechanism of pistillody mutation in wheat.

As one of the most important crops for oil, olive (Olea europaea L.) is well-known worldwide for its commercial product “virgin olive oil” containing high-content fatty acids and many secondary metabolites. The molecular mechanisms underlying the enhanced oil content in olive remain unclear. To further investigate the molecular mechanisms of olive oil biosynthesis, we selected two olive cultivars, i.e., Kalinjot (JZ) and Coratina (KLD), at three maturity stages (MI-1, MI-3, and MI-6) for transcriptomic analysis based on Nanopore sequencing. Significant differences were observed in oil content between JZ and KLD during three maturity stages. Enrichment analysis revealed significant enrichment of differentially expressed genes (DEGs) in metabolic pathways of photosynthesis, amino acid biosynthesis, response to stress, and energy metabolism, in particular, fatty acid metabolism. A total of 170 (31.54% of 539 genes involved in oil synthesis) DEGs were further investigated based on expression analysis to identify their molecular functions in oil biosynthesis in olive. A co-expression network based on 714 transcription factors and their targeted genes in oil biosynthesis was constructed. Our study provided novel experimental evidence to investigate the molecular mechanisms of olive oil biosynthesis and to improve the breeding of olive varieties with enhanced oil contents.

China, as a contrary climate to the Mediterranean-climate region, is massive in planting olive (Olea europaea) cultivation as an important oil crop. Nonetheless, Chinese olive leaves have received little attention and there is little information about the phenols content. Therefore, in this study, a multiple-response optimization was performed to maximize the total phenolic and oleuropein content (TPC and OEC) by ultrasound-assisted extraction, and the aged and young leaves prepared from six Chinese cultivars from January to December were investigated concerning seven main phenolic composition. Under optimal conditions (power 260 W, time 10 min, liquid-solid ratio 30 mL/g, and 50% ethanol), the highest TPC (197.32 mg/g DM) and OEC (74.68 mg/g DM) were obtained. Findings revealed that the optimal olive leaves for phenolic compounds were the young leaves in spring and winter, being oleuropein and luteolin-4′-O-glucoside present in higher level, and the “Koroneiki” and “Jiufeng” cultivars were relatively stable. Furthermore, antioxidant potential of the phenol extract and oleuropein was also evaluated based on the reducing power and scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH)and superoxide radical assays, and a higher antioxidant effect of oleuropein was observed compared to the phenol extract. In addition, oleuropein showed anticancer activity against HeLa cells, with a minimum inhibitory concentration (EC50) value of 0.19 mg/mL at 48 h. These findings revealed an attractive source of biological substances for further development and utilization of Chinese olive leaves.

High molecular weight (HMW) glutenin, one of the important storage proteins of wheat, mainly confers end-use quality of wheat grain. Among the loci of HMW-GS, the locus D1 determines the breaking quality of bread wheat dough mostly. Synthetic hexaploid wheat (SHW) inherits vast genetic diversity in the D genome of Aegilops tauschii and has gradually been used as a bridge-tool for wheat improvement. Therefore, more and more HMW-GS subunit types of Ae. tauschii have been introgressed into the common wheat with irresistible application of SHW in wheat breeding. However, the traditional SDS-PAGE couldn’t distinguish Dtx5 of Ae. tauschii from Dx5 of common wheat. In this study, we developed two AS-PCR markers based on three SNPs in the HMW-GS D1 sequences of Ae. tauschii and common wheat. The sharp and stable fragments amplified by designed AS-PCR primers indicated their availability and convenience in Dtx5 and Dx5 identification. And Dx5 of common wheat obtained the amplified fragments by AS-PCR primers, while no fragment was amplified for Dtx5 of Ae. tauschii. And the amplified results were consistent in both pairs of AS-PCR primers. Moreover, Dtx5 is more highly homologous with Dx2 than Dx5 from their protein sequences.

The seasonal changes in the chemical composition of Olea europaea leaves from January to December at Liangshan (China) have been investigated. The highest total phenolic content (TPC), total flavonoid content (TFC), and free amino acid content (FAAC) levels were found in May and December, while the lowest levels were detected in April and September. The soluble protein content (SPC) and the soluble sugar content (SSC) were highest in spring but lowest in summer and winter. The levels of major phenolic compounds, including oleuropein, and luteolin-4&rsquo, O-glucoside, followed by apigenin-7-O-glucoside, quercetin, rutin, luteolin, and apigenin, increased during spring and winter but decreased during summer and autumn. In addition, phenolic extracts (PEs) showed dose-dependent antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide radical scavenging activity assays, the reducing power was tested. The anticancer activities of PE at various concentrations were assessed by a cell counting kit-8 (CCK-8), and the IC50 (50% effective concentration) to HEK293, HeLa, and S180 cells were 841.48, 7139, and 457.69 &mu, g/mL, respectively. PE-treated S180 cells inhibited proliferation through activation of caspase-3/9 and disruption of the mitochondrial membrane potential. Thus, PE in Liangshan olive leaves possessed strong antioxidant and anticancer potential, and spring and winter were determined as optimal harvesting seasons.

Four polysaccharides (LVP-u, LVP-m, LVP-e, and LVP-h) were extracted from the fruiting bodies of Lactarius vividus by an ultrasonic-assisted extraction method, microwave-assisted extraction method, enzyme-assisted extraction method, and hot water extraction method, respectively. Then, the effect of extraction methods on yields, preliminary structural properties, and antioxidant activities was systematically investigated using the weighing method, chemical composition analysis, high-performance gel permeation chromatography (HPGPC), high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), radical scavenging, and metal ion chelating assays. Results demonstrated that the four L. vividus polysaccharides (LVPs) were all combined with protein, and the yield of LVP-u was higher than others. Molecular weight distribution, monosaccharide and amino acid compositions, and microstructures among the four LVPs were significantly different. Moreover, the LVPs showed significant antioxidant activities in a dose-dependent manner, and LVP-e demonstrated better antioxidant activities in superoxide anion radical scavenging activity assays and metal ion chelating activity assays, while LVP-u showed higher activity in its hydroxyl radical scavenging ability.

Hydroxytyrosol (HT) is the main bioactive compound in olive leaves. However, olive leaves contain a lower level of HT and the extraction process of HT was rarely optimized. In this study, compared with two extraction methods, ultrasound was found to have a positive effect on improving the yield of HT. Therefore, ultrasound was used to assist hydrolysis of hydrochloric acid to extract HT from olive leaves. Response surface method and macroporous resins were applied to optimize the extraction process as well as enrichment of HT. The results showed that ultrasonic extraction time had a significant effect on the yield and the optimal extraction conditions were obtained: ultrasonic time was 120 min, hydrochloric acid concentration was 1.60 mol/L and the liquid-to-material ratio was 60.00 mL/g. Under the optimal extraction condition, the yield of HT was 14.11 ± 0.12 mg/g. NKA-Ⅱ macroporous resin was proved to be a suitable resin to enrich HT from extraction solution. The optimal condition for enriching HY was 250 mL of loading solution at the flow rate of 1.5 mL/min with 40 mL volume of 75% ethanol–eluent at a flow rate of 1.0 mL/min. The concentration of HT changed from 2.27% to 9.25% after enrichment by macroporous resin.