The complete chloroplast genome of a medicinal plant Viscum articulatum Burm.f. (Loranthaceae).

Viscum articulatum is usually used as famous ethno-medicinal plant and popular drink in many provinces of China. In this study, the characterization of the complete chloroplast genome of V. articulatum was analyzed using the Illumina NovaSeq platform. The whole chloroplast genome sequence of V. articulatum is 131,825 including a large single-copy region (LSC, 76,069 bp), a small single-copy region (SSC, 8990 bp), and a pair of repeated regions (IRs, 23,383 bp, each). Further gene annotation in our study revealed the chloroplast genome contains 114 genes, including 36 tRNA genes, 8 rRNA genes and 70 protein-coding genes. A total of 118 simple sequence repeats (SSRs) were identified in the chloroplast genome. Phylogenetic development was analyzed based on V. articulatum with other species of Loranthaceae, the phylogenetic tree in our study revealed that V. articulatum is a lineage independent of other species in genus Viscum.

Characterization of the complete chloroplast genome of medical plant Curculigo orchioides Gaertn. (Amaryllidaceae).

Curculigo orchioides Gaertn. distributed in subtropical regions of Asia including southern China and India. The plant is used as a traditional medicine in China for the treatment of menorrhagia, osteoporosis, and other gynecological problems. The complete chloroplast genome was reported in this study using the Illumina NovaSeq platform. The whole genome of this species was 157,472 bp in length, with a total GC content of 37.44%. The large single copy (LSC) was 86,507 bp, the small single copy (SSC) was 16,867 bp, and both of the two inverted repeats (IRs) were 27,049 bp, respectively. A total of 132 unique genes were identified, among which are 86 protein-coding genes, 38 tRNA genes and 8 rRNA genes. The phylogenetic analysis revealed that C. orchioides was highly clustered with C. capitulata. Our study will provide useful fundamental data for further phylogenetic and evolutionary studies of C. orchioides.

The complete chloroplast genome sequence of Ficus altissima (Moraceae).

Ficus altissima plays an important role on biodiversity in tropical forests. In this study, the complete chloroplast genome sequence and the genome features of F. altissima were analyzed using the Illumina NovaSeq platform. The whole chloroplast genome sequence of F. altissima is 160,251 including a large single-copy region (LSC, 88,468 bp), a small single-copy region (SSC, 20,009 bp), and a pair of repeat regions (IRs, 25,887 bp, each). Further gene annotation revealed the chloroplast genome contains 124 genes, including 79 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. A total of 82 simple sequence repeats (SSRs) were identified in the chloroplast genome. Phylogenetic development was analyzed based on F. altissima with other species of Moraceae. This information will be useful for study on the evolution and genetic diversity of F. altissima in the future.

Hydrogen sulfide acts downstream of jasmonic acid to inhibit stomatal development in Arabidopsis.

Main conclusion: Jasmonic acid (JA) negatively regulates stomatal development by promoting LCD expression and hydrogen sulfide (H2S) biosynthesis. H2S inhibits the initiation of stomata formation and acts upstream of SPEECHLESS. Abstract: Stomatal development is strictly regulated by endogenous signals and environmental cues. We recently revealed that jasmonic acid (JA) negatively regulates stomatal development in Arabidopsis thaliana cotyledons (Han et al., Plant Physiol 176:2871-2885, 2018), but the underlying molecular mechanism remains largely unknown. Here, we uncovered a role for H2S in regulating stomatal development. The H2S scavenger hypotaurine reversed the JA-induced repression of stomatal development in the epidermis of wild-type Arabidopsis. The H2S-deficient mutant lcd displayed increased stomatal density and stomatal index values, which were rescued by treatment with sodium hydrosulfide (NaHS; an H2S donor) but not JA, suggesting that JA-mediated repression of stomatal development is dependent on H2S biosynthesis. The high stomatal density of JA-deficient mutants was rescued by exogenous NaHS treatment. Further analysis indicated that JA positively regulates LCD expression, L-cysteine desulfhydrases (L-CDes) activity, and endogenous H2S content. Furthermore, H2S represses the expression of stomate-associated genes and functions downstream of stomate-related signaling pathway components TOO MANY MOUTHS (TMM) and STOMATAL DENSITY AND DISTRIBUTION1 (SDD1) and upstream of SPEECHLESS (SPCH). Therefore, H2S acts downstream of JA signaling to regulate stomatal development in Arabidopsis cotyledons.