The complete plastome sequence of Heuchera micrantha Douglas ex Lindl. (Saxifragaceae), an ornamental plant.

The perennial herb Heuchera micrantha (Saxifragaceae) is a popular ornamental plant. However, the plastome sequence of H. micrantha has not been reported yet. Here, we assembled the complete plastome of H. micrantha using Illumina high-throughput pair-end sequencing. The plastome is a circular DNA molecule of 155,469 bp, comprising a pair of inverted repeat (IR, 25,654 bp) regions, a small single copy (SSC, 18,050 bp) region, and a large single copy (LSC, 86,111 bp) region. It encodes 129 genes, of which 84 are protein-coding genes, 37 are transfer RNAs, and eight are rRNAs. The total GC content is 37.8%. Phylogenetic analysis shows that H. micrantha, together with three other Heuchera species is clustered with Tiarella cordifolia. This complete plastome is beneficial for future genetic research on the Heuchera group.

The Chromosome-Scale Assembly of the Curcuma alismatifolia Genome Provides Insight Into Anthocyanin and Terpenoid Biosynthesis.

Curcuma alismatifolia, a bulbous flower known for its showy bracts, is widely used around the world as a cut flower, potted, and garden plant. Besides its ornamental value, this species is rich in terpenoid metabolites and could serve as a resource for essential oils. Here, we report a chromosome-level genome assembly of C. alismatifolia and describe its biosynthetic pathways for anthocyanins and terpenoids. This high-quality, assembled genome size is 991.3 Mb with a scaffold N50 value of 56.7 Mb. Evolutionary analysis of the genome suggests that C. alismatifolia diverged from Zingiber officinale about 9.7 million years ago, after it underwent a whole-genome duplication. Transcriptome analysis was performed on bracts at five developmental stages. Nine highly expressed genes were identified, encoding for six enzymes downstream of the anthocyanin biosynthetic pathway. Of these, one gene encoding F3'5'H might be a key node in the regulation of bract color formation. Co-expression network analysis showed that MYB, bHLH, NAC, and ERF transcription factors collectively regulated color formation in the bracts. Characterization of terpenoid biosynthesis genes revealed their dispersal and tandem duplications, both of which contributed greatly to the increase in the number of terpene synthase genes in C. alismatifolia, especially to species-specific expansion of sesquiterpene synthase genes. This work facilitates understanding of genetic basis of anthocyanin and terpenoid biosynthesis and could accelerate the selective breeding of C. alismatifolia varieties with higher ornamental and medicinal value.

The complete chloroplast genome of Plantago fengdouensis (Plantaginaceae): an endemic and Endangered species from China.

This study was the first report about the complete chloroplast genome of Plantago fengdouensis (Plantaginaceae). The circular whole cp genome of P. fengdouensis was in a total length 164,976 bp with the typical quadripartite structure of angiosperms, containing two inverted repeats (IRs) of 38,644 bp separated by a large single-copy (LSC) region and a small single-copy (SSC) region of 82,972 and 4716 bp, respectively. The plastid genome of P. fengdouensis contains 113 genes, including 79 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. The overall GC content of P. fengdouensis plastid genome is 38.0% and the corresponding values in LSC, SSC, and IR regions are 36.6, 30.2, and39.9%, respectively.