Search

The plant hormone gibberellic acid (GA) is important for plant growth and productivity. Actin-related proteins (ARPs) also play central roles in plant growth, including cell elongation and development. However, the relationships between ARPs and GA signaling and biosynthesis are not fully understood. Here, we isolated OsGASD, encoding an ARP subunit from rice (Oryza sativa), using the Ac/Ds knockout system. The osgasd knockout (Ko) mutation reduced GA3 content in shoots as well as plant growth and height. However, GA application restored the plant height of the osgasd Ko mutant to a height similar to that of the wild type (WT). Rice plants overexpressing OsGASD (Ox) showed increased plant height and grain yield compared to the WT. Transcriptome analysis of flag leaves of OsGASD Ox and osgasd Ko plants revealed that OsGASD regulates cell development and the expression of elongation-related genes. These observations suggest that OsGASD is involved in maintaining GA homeostasis to regulate plant development, thereby affecting rice growth and productivity.

Caulophyllum robustum, commonly named Asian blue cohosh, is a perennial herb in the family Berberidaceae. It has traditionally been used for folk medicine in China. We isolated berberine from the leaves, stem, roots, and fruits of C. robustum, and this is the first report on berberine in this species. Transcriptome analysis was conducted for the characterization of berberine biosynthesis genes in C. robustum, in which, all the genes for berberine biosynthesis were identified. From 40,094 transcripts, using gene ontology (GO) analysis, 26,750 transcripts were assigned their functions in the categories of biological process, molecular function, and cellular component. In the analysis of genes expressed in different tissues, the numbers of genes in the categories of intrinsic component of membrane and transferase activity were up-regulated in leaves versus stem. The berberine synthesis genes in C. robustum were characterized by phylogenetic analysis with corresponding genes from other berberine-producing species. The co-existence of genes from different plant families in the deepest branch subclade implies that the differentiation of berberine synthesis genes occurred early in the evolution of berberine-producing plants. Furthermore, the copy number increment of the berberine synthesis genes was detected at the species level.

The annual herb Euphorbia maculata L. produces anti-inflammatory and biologically active substances such as triterpenoids, tannins, and polyphenols, and it is used in traditional Chinese medicine. Of these bioactive compounds, terpenoids, also called isoprenoids, are major secondary metabolites in E. maculata. Full-length cDNA sequencing was carried out to characterize the transcripts of terpenoid biosynthesis reference genes and determine the copy numbers of their isoforms using PacBio SMRT sequencing technology. The Illumina short-read sequencing platform was also employed to identify differentially expressed genes (DEGs) in the secondary metabolite pathways from leaves, roots, and stems. PacBio generated 62 million polymerase reads, resulting in 81,433 high-quality reads. From these high-quality reads, we reconstructed a genome of 20,722 genes, in which 20,246 genes (97.8%) did not have paralogs. About 33% of the identified genes had two or more isoforms. DEG analysis revealed that the expression level differed among gene paralogs in the leaf, stem, and root. Whole sets of paralogs and isoforms were identified in the mevalonic acid (MVA), methylerythritol phosphate (MEP), and terpenoid biosynthesis pathways in the E. maculata L. The nucleotide information will be useful for identifying orthologous genes in other terpenoid-producing medicinal plants.