Crocins are a group of highly valuable water-soluble carotenoids that are reported to have many pharmacological activities, such as anticancer properties, and the potential for treating neurodegenerative diseases including Alzheimer’s disease. Crocins are mainly biosynthesized in the stigmas of food–medicine herbs Crocus sativus L. and Gardenia jasminoides fruits. The distribution is narrow in nature and deficient in resources, which are scarce and expensive. Recently, the synthesis of metabolites in the heterologous host has opened up the potential for large-scale and sustainable production of crocins, especially for the main active compounds crocin I and crocin II. In this study, GjCCD4a, GjALDH2C3, GjUGT74F8, and GjUGT94E13 from G. jasminoides fruits were expressed in Nicotiana benthamiana. The highest total content of crocins in T1 generation tobacco can reach 78,362 ng/g FW (fresh weight) and the dry weight is expected to reach 1,058,945 ng/g DW (dry weight). Surprisingly, the primary effective constituents crocin I and crocin II can account for 99% of the total crocins in transgenic plants. The strategy mentioned here provides an alternative platform for the scale-up production of crocin I and crocin II in tobacco.

Baicalein is a valuable flavonoid isolated from the medicinal plant Scutellaria baicalensis Georgi, which exhibits intensive biological activities, such as anticancer and antiviral activities. However, its production is limited in the root with low yield. In this study, In-Fusion and 2A peptide linker were developed to assemble SbCLL-7, SbCHI, SbCHS-2, SbFNSII-2 and SbCYP82D1.1 genes driven by the AtPD7, CaMV 35S and AtUBQ10 promoters with HSP, E9 and NOS terminators, and were used to engineer baicalein biosynthesis in transgenic tomato plants. The genetically modified tomato plants with this construct synthesized baicalein, ranging from 150 ng/g to 558 ng/g FW (fresh weight). Baicalein-fortified tomatoes have the potential to be health-promoting fresh vegetables and provide an alternative source of baicalein production, with great prospects for market application.

​Alignment problems may be complicated and diverse and the performance of the existing alignment-filtering tools, particularly their potential effect on phylogenetic reconstruction, have remained debated or limitedly explored. ​In the present study, we developed a new R package named alignmentFilter to treat the diverse alignment problems, especially masking ambiguously-aligned or overly divergent segments using a newly devised grouping-regrouping algorithms acting on sequence divergence in each of sliding windows throughout alignment. Then we tested and compared the power and accuracy of the prevalent alignment-filtering tools, particularly the effect on phylogeny based on Angiospermae genome-scale data and simulated data. ​The results indicate the alignment-filtering methods alone may affect the phylogeny decisively, producing (strongly-supported) phylogenetic conflicts. In most cases, alignmentFilter most efficiently improves phylogeny, yielding more congruent phylogeny regardless of phylogeny-reconstruction methods, producing phylogeny more concordant to the priori tree regarding to both topology and branch length in simulation, and most efficiently decreasing the root-to-tip length heterogeneity that is implied to be negatively correlated with topological accuracy. ​The concepts and algorithms of alignmentFilter are quite distinct from existing alignment-filtering methods. It is not susceptible to specific types of alignment errors that usually baffle other methods and can reach the optimal solution frequently with lowest computation complexity. The biological or statistical sense of the key optional stringency-controlling parameter is more straightforward and the setting and outcome may be more adjustable or predictable. A better and more comprehensive solution of alignment problems in this study will benefit tremendous downstream analyses sourced from alignment and phylogeny.

Flemingia macrophylla (Willd.) Prain is an ethnomedicinal plant with high nutritional and medicinal values. In this study, we report the complete chloroplast genome of F. macrophylla. The chloroplast genome has a typical quadripartite structure with a genome size of 152,988 bp, including a large single-copy (LSC) of 83,634 bp, a small single-copy (SSC) of 17,774 bp and two inverted repeats (IRs) of 25,790 bp. The genome contains 129 genes, including 84 protein-coding, 37 tRNA and 8 rRNA genes. The overall GC content is 35.1%. Phylogenetic analysis showed that F. macrophylla grouped with a clade containing the genera of Fagelia, Dolichos, Eriosema, Dunbaria and Cajanus in Fabaceae. This study provides essential data and insight for understanding the phylogenetic placement of Flemingia.

Background: Hemiboea yongfuensis is a recently discovered critically endangered species. It is exclusive to the limestone regions of Yongfu County, Guilin, Guangxi. Currently, there is a lack of mitogenome data for Hemiboea species, hindering the potential of disclosing the evolutionary processes of the mitochondrial genome, which has been far less assembled and shown to be complex in the plant kingdom. Moreover, it prevents potential applications of mitochondrial genome data in phylogenetics and plant adaption, breeding, and conservation. Results: In order to reveal the mitochondrial features and variations and explore the usefulness of mitochondrial genes in phylogenetics, in this study, we assembled the complete mitogenome of H. yongfuensis using PacBio HiFi long reads, and analyzed its codon usage bias, RNA editing sites, repetitive sequences, sequence lateral transfer, phylogenetic relationships, and synteny. The linear mitochondrial genome assembly we obtained has a length of 619,997 bp and a GC content of 43.63%. The assembly encompasses 61 genes, which include 37 protein-coding genes (PCGs), 21 transfer RNA (tRNA) genes, and 3 ribosomal RNA (rRNA) genes. Importantly, our analysis uncovered a significant presence of repetitive sequences with a high proportion of forward repeats in the mitogenome and significant transposition of sequences from the chloroplast to mitochondrion. Additionally, we revealed the codon usage characteristics of protein-coding genes and identified numerous RNA editing events. Furthermore, we assessed the collinearity of the species in the Gesneriaceae family and found rampant reorganizations. The phylogenetic analyses based on the mitochondrial PCGs for the entire Lamiales order show the monophyly of Gesneriaceae as well as other families and a general high phylogenetic resolution. Conclusions: Our study provides the first mitogenome data for H. yongfuensis and the genus Hemiboea, expanding the rapidly increasing but yet limited plant mitogenome resources. It enhances our understanding of the mitogenome and Lamiales evolution, whereas more potentials of the mitogenome data, such as its possible functions in adaptation to limestone habitats, conservation, and germplasm breeding, remain under-exploited. This first reported Hemiboea mitogenome in addition to more mitogenomes from the same and related species would shed further light on these unresolved issues in future studies.