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Ginkgo ( Ginkgo biloba L.) exhibits high level of resistance to various abiotic stresses, yet has undergone only minor morphological changes through millions of years. The conversion of membrane lipid components may play an important role in the temperature acclimation of plants. Stearoyl-ACP desaturase, microsomal ω-6 (Δ12) desaturase, and plastidial ω-6 (Δ12) desaturase are important enzymes in the unsaturated fatty acid biosynthetic pathway. In this study, full-length cDNA sequences of GbSAD, GbFAD2, and GbFAD6 were isolated from fresh leaves of ginkgo by rapid amplification of cDNA ends and polymerase chain reaction (PCR). Sequence analysis demonstrated that the cDNAs and deduced proteins had high similarity to other reported corresponding cDNAs and proteins. Real-time PCR revealed that transcripts of GbSAD and GbFAD2 in leaves were induced by cold stress (4 °C, 15 °C), but inhibited by high temperature (35 °C, 45 °C), whereas GbFAD6 is expressed constitutively at different temperatures. [ABSTRACT FROM AUTHOR]

Taxol, a natural product derived from Taxus, is one of the most effective natural anticancer drugs and the biosynthetic pathway of Taxol is the basis of heterologous bio-production. Here, we report a high-quality genome assembly and annotation of Taxus yunnanensis based on 10.7 Gb sequences assembled into 12 chromosomes with contig N50 and scaffold N50 of 2.89 Mb and 966.80 Mb, respectively. Phylogenomic analyses show that T. yunnanensis is most closely related to Sequoiadendron giganteum among the sampled taxa, with an estimated divergence time of 133.4−213.0 MYA. As with most gymnosperms, and unlike most angiosperms, there is no evidence of a recent whole-genome duplication in T. yunnanensis. Repetitive sequences, especially long terminal repeat retrotransposons, are prevalent in the T. yunnanensis genome, contributing to its large genome size. We further integrated genomic and transcriptomic data to unveil clusters of genes involved in Taxol synthesis, located on the chromosome 12, while gene families encoding hydroxylase in the Taxol pathway exhibited significant expansion. Our study contributes to the further elucidation of gymnosperm relationships and the Taxol biosynthetic pathway. Song, Fu, Yang, Niu, Tian, et al. present a high-quality genome assembly and transcriptome data of Taxus yunnanensis, a plant belonging to the Taxus genus known for sources of traditional medicine and natural anticancer drugs. This study explores the Taxus evolutionary history and sheds light on the Taxol biosynthetic pathway. [ABSTRACT FROM AUTHOR]

The purpose of this work was to study the combined effect of high hydrostatic pressure (HHP) and enzymatic hydrolysis treatment on the hydrolysis and allergenicity of ginkgo seed proteins (GSPs). Four food-grade proteases (papain, alcalase, pepsin, and neutrase) were used, and HHP (200, 300, and 400 MPa separately) was applied prior to hydrolysis. The extent of hydrolysis was measured with the o-phthaldialdehyde method, SDS-PAGE, and MALDI-TOF-MS, and the allergenicity was assessed with a Western blot and enzyme-linked immunosorbent assay (ELISA). The results showed that HHP could significantly improve the extent of proteolysis by papain, alcalase, or pepsin and reduce the antigenicity of GSP, whereas neutrase showed poor effects at any pressure. Papain and alcalase showed the highest proteolysis at 300 MPa, followed by pepsin at 400 MPa, and all of the obtained hydrolysates showed molecular weights lower than 10 kDa; furthermore, papain or alcalase at 300 MPa as well as pepsin at 400 MPa reduced antigenicity by more than 95 %, and all of the immunoreactive bands disappeared in the obtained hydrolysates. These results suggest that HHP can enhance the hydrolysis of GSP by certain enzymes and reduce the residual antigenicity of the hydrolysates. The obtained hypoallergenic hydrolysates could be used as a source of peptides for food ingredients. [ABSTRACT FROM AUTHOR]

As one of the most ancient tree species, the codon usage pattern analysis of Ginkgo biloba is a useful way to understand its evolutionary and genetic mechanisms. Several studies have been conducted on angiosperms, but seldom on gymnosperms. Based on RNA-Seq data of the G. biloba transcriptome, amount to 17,579 unigenes longer than 300 bp were selected and analyzed from 68,547 candidates. The codon usage pattern tended towards more frequently use of A/U-ending codons, which showed an obvious gradient progressing from gymnosperms to dicots to monocots. Meanwhile, analysis of high/low-expression unigenes revealed that high-expression unigenes tended to use G/C-ending codons together with more codon usage bias. Variation of unigenes with different functions suggested that unigenes involving in environment adaptation use G/C-ending codons more frequently with more usage bias, and these results were consistent with the conclusion that the formation of G. biloba codon usage bias was dominated by natural selection. [ABSTRACT FROM AUTHOR]