Jasmonic acid (JA) carboxyl methyltransferase (JMT), a key enzyme in jasmonate-regulated plant responses, may be involved in plant defense and development by methylating JA to MeJA, thus influencing the concentrations of MeJA in plant. In this study, we isolated the JMT gene from Salvia miltiorrhiza, an important medicinal plant widely used to treat cardiovascular disease. We present a genetic manipulation strategy to enhance the production of phenolic acids by overexpresion SmJMT in S. miltiorrhiza. Global transcriptomic analysis using RNA sequencing showed that the expression levels of genes involved in the biosynthesis pathway of phenolic acids and MeJA were upregulated in the overexpression lines. In addition, the levels of endogenous MeJA, and the accumulation of rosmarinic acid (RA) and salvianolic acid (Sal B), as well as the concentrations of total phenolics and total flavonoids in transgenic lines, were significantly elevated compared with the untransformed control. Our results demonstrate that overexpression of SmJMT promotes the production of phenolic acids through simultaneously activating genes encoding key enzymes involved in the biosynthesis pathway of phenolic acids and enhancing the endogenous MeJA levels in S. miltiorrhiza.

The plant SABATH gene family is a group of O-methyltransferases (O-MTs), which belongs to the S-adenosyl-l-methionine-dependent methyltransferases (SAM-MTs). The resulting reaction products of SABATH genes play an important role in various processes of plant development. In this study, a total of 30 SABATH genes were detected in Salvia miltiorrhiza, which is an important medicinal plant, widely used to treat cardiovascular disease. Multiple sequence alignment and phylogenetic analyses showed that SmSABATH genes could be classified into three groups. The ratios of non-synonymous (Ka) and synonymous (Ks) substitution rates of 11 pairs paralogous of SmSABATH genes revealed that the SmSABATH genes had gone through purifying selection. Positive selection analyses using site models and branch-site models indicated that SmSABATH genes had undergone selective pressure for adaptive evolution. Functional divergence analyses suggested that the SmSABATH subgroup genes were divergent in terms of functions and positive selection sites that contributed to a functional divergence among the subgroups that were detected. Tissue-specific expression showed that the SABATH gene family in S. miltiorrhiza was primarily expressed in stems and leaves.

Low molecular weight metabolites are important plant hormones and signaling molecules, and play an important part among the processes of plant development. Their activities may also be affected by the chemical modifications of methylation performed by SABATH. In this study, a total of 24 and 21 SABATH genes in Arabidopsis and rice, respectively, were identified and taken a comprehensive study. Phylogenetic analysis showed that AtSABATH and OsSABATH genes could be classified into 4 major groups and 6 subgroups. Gene expansion analysis showed that the main expansion mechanism of SABATH gene family in Arabidopsis and rice was tandem duplication and segmental duplication. The ratios of nonsynonymous (Ka) and synonymous (Ks) substitution rates of 12 pairs paralogous of AtSABATH and OsSABATH genes indicated that the SABATH gene family in Arabidopsis and rice had gone through purifying selection. Positive selection analysis with site models and branch-site models revealed that AtSABATH and OsSABATH genes had undergone selective pressure for adaptive evolution. Motif analysis showed that certain motifs only existed in specific subgroups or species, which indicated that the SABATH proteins of Arabidopsis and rice appear divergence in different species and subgroups. Functional divergence analysis also suggested that the AtSABATH and OsSABATH subgroup genes had functional differences, and the positive selection sites which contributed to functional divergence among subgroups were detected. These results provide insights into functional conservation and diversification of SABATH gene family, and are useful information for further elucidating SABATH gene family functions.

The complete chloroplast sequence of Alocasia macrorrhizos is 154 995 bp in length, containing a pair of inverted repeats of 25 944 bp separated by a large single-copy (LSC) region and a small single-copy (SSC) region of 87 366 bp and 15 741 bp, respectively. The chloroplast genome encodes 132 predicted functional genes, including 87 protein-coding genes, four ribosomal RNA genes, and 37 transfer RNA genes, 18 of which are duplicated in the inverted repeat regions. In these genes, 16 genes contained single intron and two genes comprising double introns. A maximum-likelihood phylogenetic analysis using complete chloroplast genome revealed that A. macrorrhizos does not belong to Araceae family, which infers that the A. macrorrhizos is distant from the species in Araceae family.

Pericallis hybrida is a very prevalent decorative plant worldwide. Here, we report the assembly of the complete nucleotide sequence of the P. hybrida chloroplast genome using the program MITObim v1.7 after whole genome shotgun sequencing. The complete chloroplast genome of P. hybrida (GenBank accession number: KT285537) consists of 151,267 bp and includes a pair of inverted repeats (IR) of 23,595 bp separated by one small and one large single copy region (SSC and LSC) of 18,330 bp and 85,747 bp, respectively. The genome has a 37.3% GC content and contains 132 genes coding for 87 proteins. Phylogenetic analyses using complete chloroplast genome revealed that P. hybrida belongs to the Senecioneae of Asteraceae family, which is conformed to the traditional classification.

Auxin, as a central phytohormone and signaling molecule, plays a crucial role in plant growth and development. The activity of auxin is tightly regulated by the auxin-responsive GH3 gene family. In this study, a total of 40 GH3 genes in A. thaliana , S. miltiorrhiza , and O. sativa were identified and subjected to comprehensive study. Phylogenetic analysis revealed that those GH3 genes can be classified into three distinct subgroups, with 11 pairs of paralogs identified. Genetic divergence analysis indicated that the GH3 gene family had predominantly experienced purifying selection as evidenced by the Ka/Ks ratio being less than 1 for all 11 paralogs pairs. Positive selection analysis with the site and branch-site models further suggested that SmGH3 AtGH3 and OsGH3 genes had gone through purifying selective pressure for adaptive evolution. Motif analysis indicated that group-specific motifs may contribute to functional divergence across species and subgroups. Functional divergence analysis confirmed that subgroup-specific genes have experienced functional divergence during evolution, and elucidated the molecular mechanisms underlying their divergent functions. The tissue-specific expression analysis of SmGH3 AtGH3 and OsGH3 genes revealed that these genes might perform distinct functions in different tissues. This study performed a comprehensive bioinformatics analysis of the GH3 gene family, offering valuable information to further elucidate the functional roles of GH3 genes.