Lycium chinense is well known in traditional Chinese herbal medicine for its medicinal value and composition, which have been widely studied for decades. However, further research on Lycium chinense is limited due to the lack of transcriptome and genomic information. The transcriptome of L. chinense was constructed by using an Illumina HiSeq 2000 sequencing platform. All 56,526 unigenes with an average length of 611 nt and an N50 equaling 848 nt were generated from 58,192,350 total raw reads after filtering and assembly. Unigenes were assembled by BLAST similarity searches and annotated with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology identifiers. Using these transcriptome data, the majority of genes that are associated with phenylpropanoid biosynthesis in L. chinense were identified. In addition, phenylpropanoid biosynthesis-related gene expression and compound content in different organs were analyzed. We found that most phenylpropanoid genes were highly expressed in the red fruits, leaves, and flowers. An important phenylpropanoid, chlorogenic acid, was also found to be extremely abundant in leaves. Using Illumina sequencing technology, we have identified the function of novel homologous genes that regulate metabolic pathways in Lycium chinense.

Kenaf (Hibiscus cannabinus) is cultivated worldwide for its fiber; however, the medicinal properties of this plant are currently attracting increasing attention. In this study, we investigated the expression levels of genes involved in the biosynthesis of kaempferitrin, a compound with many biological functions, in different kenaf organs. We found that phenylalanine ammonia lyase (HcPAL) was more highly expressed in stems than in other organs. Expression levels of cinnamate 4-hydroxylase (HcC4H) and 4-coumarate-CoA ligase (Hc4CL) were highest in mature leaves, followed by stems and young leaves, and lowest in roots and mature flowers. The expression of chalcone synthase (HcCHS), chalcone isomerase (HcCHI), and flavone 3-hydroxylase (HcF3H) was highest in young flowers, whereas that of flavone synthase (HcFLS) was highest in leaves. An analysis of kaempferitrin accumulation in the different organs of kenaf revealed that the accumulation of this compound was considerably higher (>10-fold) in leaves than in other organs. On the basis of a comparison of kaempferitrin contents with the expression levels of different genes in different organs, we speculate that HcFLS plays an important regulatory role in the kaempferitrin biosynthetic pathway in kenaf.

Riboflavin (vitamin B2) is the precursor of flavin mononucleotide and flavin adenine dinucleotide—essential cofactors for a wide variety of enzymes involving in numerous metabolic processes. In this study, a partial-length cDNA encoding bifunctional GTP cyclohydrolase II/3,4-dihydroxy-2-butanone-4-phosphate synthase (LcRIBA), 2 full-length cDNAs encoding lumazine synthase (LcLS1 and LcLS2), and a full-length cDNA encoding riboflavin synthase (LcRS) were isolated from Lycium chinense, an important traditional medicinal plant. Sequence analyses showed that these genes exhibited high identities with their orthologous genes as well as having the same common features related to plant riboflavin biosynthetic genes. LcRIBA, like other plant RIBAs, contained a DHBPS region in its N terminus and a GCHII region in its C-terminal part. LcLSs and LcRS carried an N-terminal extension found in plant riboflavin biosynthetic genes unlike the orthologous microbial genes. Quantitative real-time polymerase chain reaction analysis showed that 4 riboflavin biosynthetic genes were constitutively expressed in all organs examined of L. chinense plants with the highest expression levels found in the leaves or red fruits. LcRIBA, which catalyzes 2 initial reactions in riboflavin biosynthetic pathway, was the highest transcript in the leaves, and hence, the richest content of riboflavin was detected in this organ. Our study might provide the basis for investigating the contribution of riboflavin in diverse biological activities of L. chinense and may facilitate the metabolic engineering of vitamin B2 in crop plants.

Lycium chinense is a shrub that has health benefits and is used as a source of medicines in Asia. In this study, a full-length cDNA clone encoding β-ring carotene hydroxylase (LcCHXB) and partial-length cDNA clones encoding phytoene synthase (LcPSY), phytoene desaturase (LcPDS), ξ-carotene desaturase (LcZDS), lycopene β-cyclase (LcLCYB), lycopene ε-cyclase (LcLCYE), ε-ring carotene hydroxylase (LcCHXE), zeaxanthin epoxidase (LcZEP), carotenoid cleavage dioxygenase (LcCCD1), and 9-cis epoxycarotenoid dioxygenase (LcNCED) were identified in L. chinense. The transcripts were constitutively expressed at high levels in leaves, flowers and red fruits, where the carotenoids are mostly distributed. In contrast, most of the carotenoid biosynthetic genes were weakly expressed in the roots and stems, which contained only small amounts of carotenoids. The level of LcLCYE transcripts was very high in leaves and correlated with the abundance of lutein in this plant tissue. During maturation, the levels of lutein and zeaxanthin in L. chinense fruits dramatically increased, concomitant with a rise in the level of β-cryptoxanthin. LcPSY, LcPDS, LcZDS, LcLCYB, and LcCHXE were highly expressed in red fruits, leading to their substantially higher total carotenoid content compared to that in green fruits. Total carotenoid content was high in both the leaves and red fruits of L. chinense. Our findings on the biosynthesis of carotenoids in L. chinense provide insights into the molecular mechanisms involved in carotenoid biosynthesis and may facilitate the optimization of carotenoid production in L. chinense.

Populus koreana emits a wide array of volatile organic compounds (VOCs) with potential ecological functions; however, the tissue-specific distribution and underlying regulatory mechanisms of these compounds remain poorly understood. This study employed an integrated approach combining gas chromatography-mass spectrometry (GC-MS)-based metabolomics and RNA-seq to systematically profile VOC composition and gene expression in terminal buds, stems and leaves of P. koreana. A total of 207 VOCs were identified, predominantly terpenes and aromatic compounds, exhibiting distinct tissue-specific accumulation patterns. Terminal buds were enriched in limonene and caryophyllene, while leaves showed higher concentrations of alcohols and phenolic aldehydes. Transcriptomic analysis revealed 12,733 differentially expressed genes (DEGs) among the three organs, with substantial enrichment in terpenoid and phenylpropanoid biosynthetic pathways. Notably, key upregulated genes in buds, including TPS21 and PAL1, correlated with observed VOC profiles. Weighted gene co-expression network analysis (WGCNA) further identified 6365 genes strongly associated with bud-specific VOC biosynthesis. Integrated omics analyses indicated coordinated regulation of phenylalanine metabolism and transcription factors in VOC production. These findings illuminate the molecular mechanisms underlying tissue-specific VOC accumulation in P. koreana, enhancing our understanding of metabolic specialization and ecological adaptation in woody plants.

Seed germination is a critical determinant of seedling establishment, stress resistance, and final yield. ABA catabolism plays a central role in releasing seed dormancy and promoting germination, and ABA8ox is the key rate-limiting enzyme in this process. In this study, we used wild-type maize B73, and ZmABA8ox1b CRISPR-Cas9 knockout mutant as materials to investigate the biological function of ZmABA8ox1b. Compared with the wild type, the zmaba8ox1b mutant significantly delayed seed germination and enhanced the sensitivity to exogenous ABA. Endogenous ABA content in mutant embryos was drastically increased, indicating that ZmABA8ox1b is essential for ABA degradation during germination. The loss of ZmABA8ox1b function led to the activation of the ABA signaling pathway and severely impaired the responsiveness to exogenous ABA. Moreover, the mutation disturbed the expression and ABA responsiveness of auxin, gibberellin, ethylene, jasmonic acid, and brassinosteroid pathways, leading to a hormonal network imbalance. In conclusion, ZmABA8ox1b positively regulates maize seed germination by coordinating ABA catabolism and multi-hormone signal crosstalk. This study preliminarily clarifies the molecular mechanism of ZmABA8ox1b in germination control and provides important gene resources and theoretical support for breeding maize varieties.