Overexpression of chalcone isomerase A gene in Astragalus trigonus for stimulating apigenin

Biofortification as a solution for addressing nutrient deficiencies and malnutrition

Malnutrition, defined as both undernutrition and overnutrition, is a major global health concern affecting millions of people. One possible way to address nutrient deficiency and combat malnutrition is through biofortification. A comprehensive review of the literature was conducted to explore the current state of biofortification research, including techniques, applications, effectiveness and challenges. Biofortification is a promising strategy for enhancing the nutritional condition of at-risk populations. Biofortified varieties of basic crops, including rice, wheat, maize and beans, with elevated amounts of vital micronutrients, such as iron, zinc, vitamin A and vitamin C, have been successfully developed using conventional and advanced technologies. Additionally, the ability to specifically modify crop genomes to improve their nutritional profiles has been made possible by recent developments in genetic engineering, such as CRISPR-Cas9 technology. The health conditions of people have been shown to improve and nutrient deficiencies were reduced when biofortified crops were grown. Particularly in environments with limited resources, biofortification showed considerable promise as a long-term and economical solution to nutrient shortages and malnutrition. To fully exploit the potential of biofortified crops to enhance public health and global nutrition, issues such as consumer acceptance, regulatory permitting and production and distribution scaling up need to be resolved. Collaboration among governments, researchers, non-governmental organizations and the private sector is essential to overcome these challenges and promote the widespread adoption of biofortification as a key part of global food security and nutrition strategies.

Cloning, Identification, and Functional Analysis of the Chalcone Isomerase Gene from Astragalus sinicus

Astragalus sinicus is an important winter-growing cover crop. It is widely utilized, not only as a cover crop for its benefits in fertilizing the soil but also as a landscape ground cover plant. Anthocyanins are involved in the pigmentation of plants in leaves and flowers, which is a crucial characteristic trait for A. sinicus. The formation of anthocyanins depends significantly on the enzyme chalcone isomerase (CHI). However, research on the CHI gene of A. sinicus remains unexplored. The rapid amplification of cDNA ends (RACE) approach was used in this research to clone the CHI sequence from A. sinicus (AsiCHI). The expression profiles of the AsiCHI gene in multiple tissues of A. sinicus were subsequently examined by qRT-PCR (Quantitative Real-Time PCR). Furthermore, the function of the AsiCHI was identified by the performance of ectopic expression in Arabidopsis (Arabidopsis thaliana). The outcomes revealed that the full-length cDNA of the AsiCHI gene (GeneBank: OQ870547) measured 972 bp in length and included an open reading frame of 660 bp. The encoded protein contains 219 amino acids with a molecular weight of 24.14 kDa and a theoretical isoelectric point of 5.11. In addition, the remarkable similarity between the AsiCHI protein and the CHI proteins of other Astragalus species was demonstrated by the sequence alignment and phylogenetic analysis. Moreover, the highest expression level of AsiCHI was observed in leaves and showed a positive correlation with anthocyanin content. The functional analysis further revealed that the overexpression of AsiCHI enhanced the anthocyanidin accumulation in the transgenic lines. This study provided a better understanding of AsiCHI and elucidated its role in anthocyanin production.

Cytogenetic Characterization and Metabolomic Differences of Full-Sib Progenies of Saccharum spp

Sugarcane smut is a worldwide fungal disease. Disease resistance breeding is the most economical and effective measure to prevent and control sugarcane smut. The cytogenetic characteristics and metabolomic differences of sugarcane F₁s are closely related to disease resistance. Zhongzhe 1 and G160 sugarcane from the same parents (ROC25 and Yunzhe89-7) were used; the plants were grown in accordance with the barrel method. When the seedlings had 4-5 leaves, genomic in situ hybridization (GISH) was performed; digoxigenin (DIG)-labeled female parental (ROC25)DNA and biotin-labeled male parental (Yunzhe89-7) DNA were used as probes, and the karyotypes of two hybrids were analyzed. The new sugarcane smut-resistant variety (Zhongzhe 1) and the susceptible variety (G160) derived from the same parent were analyzed via gas chromatography-mass spectrometry technology (GC-MS) to compare the metabolomic differences between them. GISH analysis revealed that the chromosome ploidy number of Zhongzhe 1 sugarcane and G160 sugarcane were 114 and 110, respectively. However, the two contain different numbers of chromosomes from the female (ROC25) and male (Yunzhe89-7) parents. Moreover, 258 significantly changed metabolites were identified in smut-resistant Zhongzhe 1, as compared with the smut-susceptible G160 sugarcane: 56 flavonoids, 52 phenolic acids, 30 lipids, 26 organic acids, 26 amino acids and derivatives, 19 nucleotides and derivatives, 5 alkaloids, 9 terpenoids, and 35 others. Multivariate statistical analysis revealed a distinct difference in metabolic pathways between Zhongzhe 1 sugarcane and G160, and both of these varieties had unique functional metabolites. Differences in chromosome composition may constitute the genetic basis for the difference in resistance to smut disease between Zhongzhe 1 sugarcane and G160 sugarcane, and a high accumulation of flavonoids, lipids, terpenoids and tannins may constitute the basis of resistance to smut disease for the Zhongzhe 1 variety.

Flavonoid Production: Current Trends in Plant Metabolic Engineering and De Novo Microbial Production

Flavonoids are secondary metabolites that represent a heterogeneous family of plant polyphenolic compounds. Recent research has determined that the health benefits of fruits and vegetables, as well as the therapeutic potential of medicinal plants, are based on the presence of various bioactive natural products, including a high proportion of flavonoids. With current trends in plant metabolite research, flavonoids have become the center of attention due to their significant bioactivity associated with anti-cancer, antioxidant, anti-inflammatory, and anti-microbial activities. However, the use of traditional approaches, widely associated with the production of flavonoids, including plant extraction and chemical synthesis, has not been able to establish a scalable route for large-scale production on an industrial level. The renovation of biosynthetic pathways in plants and industrially significant microbes using advanced genetic engineering tools offers substantial promise for the exploration and scalable production of flavonoids. Recently, the co-culture engineering approach has emerged to prevail over the constraints and limitations of the conventional monoculture approach by harnessing the power of two or more strains of engineered microbes to reconstruct the target biosynthetic pathway. In this review, current perspectives on the biosynthesis and metabolic engineering of flavonoids in plants have been summarized. Special emphasis is placed on the most recent developments in the microbial production of major classes of flavonoids. Finally, we describe the recent achievements in genetic engineering for the combinatorial biosynthesis of flavonoids by reconstructing synthesis pathways in microorganisms via a co-culture strategy to obtain high amounts of specific bioactive compounds.

Metabolomics and transcriptomics provide insights into the flavonoid biosynthesis pathway in the roots of developing Aster tataricus

Aster tataricus (L.) is an important medicinal plant in China. Its roots are rich in flavonoids, the main medicinal components. However, the molecular basis of flavonoid biosynthesis in the roots of A. tataricus remains unclear. In this study, the content of total flavonoid of A. tataricus roots at different developmental stages was measured first, and the results showed that the content of total flavonoid gradually decreased from September to November, which may be caused by the stagnation of A. tataricus growth due to the decrease in temperature after September. Then, an integrated analysis of transcriptome and metabolome was conducted on five developing stages of A. tataricus roots to identify flavonoid compositions and potential genes involved in flavonoid biosynthesis. A total of 80 flavonoid metabolites, of which 75% were flavonols and flavonoids, were identified in metabolomic analyses, among which isorhamnetin, kaempferol, quercetin, and myricetin were the main skeletons of these flavonoids. Cluster analysis divided these 80 flavonoids into 3 clusters. The compounds in cluster I mainly accumulated in S1, S3, and S5. In cluster II, the relative content of the flavonoid metabolites showed an upward trend from S2 to S4. In cluster III, the flavonoids decreased from S1 to S5. A total of 129 structural genes, including 43 PAL, 23 4CL, 9 C4H, 4 CHS, 18 CHI, 3 F3H, 5 F3'H, 1 F3'5'H, 21 FLS, and 2 FSII, and 65 transcription factors, including 22 AP2/ERF, 7 bHLH, 5 bZIP, 8 MYB, 11 NAC, and 12 WRKY, showed significant correlation with total flavonoid content. Eighteen genes (7 4CL, 5 C4H, 2 CHI, 1 F3H, and 3 FLS) and 30 genes (5 PAL, 9 4CL, 1 C4H, 2 CHI, 1 F3H, 1 DFR, 7 3AT, 1 BZ1, and 3 UGT79B1) were identified as key structural genes for kaempferol and anthocyanins biosynthesis, respectively. Our study provides valuable information for understanding the mechanism of flavonoid biosynthesis in A. tataricus root.

Integrative Analysis of Metabolome and Transcriptome Reveals the Role of Strigolactones in Wounding-Induced Rice Metabolic Re-Programming

Plants have evolved mechanisms to adapt to wounding, a threat occurring separately or concomitantly with other stresses. During the last decades, many efforts have been made to elucidate the wounding signaling transduction. However, we know little about the metabolic re-programming under wounding, let alone whether and how strigolactones (SLs) participate in this progress. Here, we reported a metabolomic and transcriptomic analysis of SLs synthetic and signal mutants in rice before and after wounding. A series of metabolites differentially responded to wounding in the SLs mutants and wild-type rice, among which flavones were enriched. Besides, the SLs mutants accumulated more jasmonic acid (JA) and jasmonyl isoleucine (JA-lle) than the wild-type rice after wounding, suggesting an interplay of SLs and JAs during responding to wounding. Further transcriptome data showed that cell wall, ethylene, and flavones pathways might be affected by wounding and SLs. In addition, we identified candidate genes regulated by SLs and responding to wounding. In conclusion, our work provides new insights into wounding-induced metabolic re-programming and the SLs’ function.

Transcriptome and metabolome reveal the accumulation of secondary metabolites in different varieties of Cinnamomum longepaniculatum

BACKGROUND

Cinnamomum longepaniculatum (Gamble) N. Chao ex H. W. Li, whose leaves produce essential oils, is a traditional Chinese medicine and economically important tree species. In our study, two C. longepaniculatum varieties that have significantly different essential oil contents and leaf phenotypes were selected as the materials to investigate secondary metabolism.

RESULT

The essential oil content and leaf phenotypes were different between the two varieties. When the results of both transcriptome and metabolomic analyses were combined, it was found that the differences were related to phenylalanine metabolic pathways, particularly the metabolism of flavonoids and terpenoids. The transcriptome results based on KEGG pathway enrichment analysis showed that pathways involving phenylpropanoids, tryptophan biosynthesis and terpenoids significantly differed between the two varieties; 11 DEGs (2 upregulated and 9 downregulated) were associated with the biosynthesis of other secondary metabolites, and 12 DEGs (2 upregulated and 10 downregulated) were related to the metabolism of terpenoids and polyketides. Through further analysis of the leaves, we detected 196 metabolites in C. longepaniculatum. The abundance of 49 (26 downregulated and 23 upregulated) metabolites differed between the two varieties, which is likely related to the differences in the accumulation of these metabolites. We identified 12 flavonoids, 8 terpenoids and 8 alkaloids and identified 4 kinds of PMFs from the leaves of C. longepaniculatum.

CONCLUSIONS

The combined results of transcriptome and metabolomic analyses revealed a strong correlation between metabolite contents and gene expression. We speculate that light leads to differences in the secondary metabolism and phenotypes of leaves of different varieties of C. longepaniculatum. This research provides data for secondary metabolite studies and lays a solid foundation for breeding ideal C. longepaniculatum plants.