The complete chloroplast genome sequence of Myricaria wardii Marquand 1929 (Tamaricaceae): a shrub species endemic to the Tibet Plateau.

Myricaria wardii Marquand 1929, endemic to the Tibet Plateau, is a perennial shrub with important medicinal and ecological values. In this study, the complete chloroplast (cp) genome of M. wardii was assembled, and the phylogenetic tree was reconstructed to evaluate the phylogenetic location of the species. The results showed that the cp genome size of the M. wardii was 155,299 bp, which contained a pair of inverted repeat (IR) regions (26,150 bp), a large single copy (LSC) region (84,715 bp), and a small single copy (SSC) region (18,284 bp). The total GC content of the cp genome was 36.30%. A total of 128 genes were annotated, consisting of 83 protein-coding genes, 37 tRNA genes and 8 rRNA genes. The phylogenetic analysis showed that M. wardii was closely related to M. prostrata. This study provides useful information for the conservation of this species and the phylogenetic analysis of Tamaricaceae.

Transcriptome Analysis of Macrophytes' Myriophyllum spicatum Response to Ammonium Nitrogen Stress Using the Whole Plant Individual.

Ammonium toxicity in macrophytes reduces growth and development due to a disrupted metabolism and high carbon requirements for internal ammonium detoxification. To provide more molecular support for ammonium detoxification in the above-ground and below-ground parts of Myriophyllum spicatum, we separated (using hermetic bags) the aqueous medium surrounding the below-ground from that surrounding the above-ground and explored the genes in these two regions. The results showed an upregulation of asparagine synthetase genes under high ammonium concentrations. Furthermore, the transcriptional down and/or upregulation of other genes involved in nitrogen metabolism, including glutamate dehydrogenase, ammonium transporter, and aspartate aminotransferase in above-ground and below-ground parts were crucial for ammonium homeostasis under high ammonium concentrations. The results suggest that, apart from the primary pathway and alternative pathway, the asparagine metabolic pathway plays a crucial role in ammonium detoxification in macrophytes. Therefore, the complex genetic regulatory network in M. spicatum contributes to its ammonium tolerance, and the above-ground part is the most important in ammonium detoxification. Nevertheless, there is a need to incorporate an open-field experimental setup for a conclusive picture of nitrogen dynamics, toxicity, and the molecular response of M. spicatum in the natural environment.

An annotated plant checklist of the transboundary volcanic Mt Elgon, East Africa.

Mt Elgon is an ancient transboundary volcanic mountain found at the Kenya-Uganda boarder possessing high plant diversity. This study documents an updated checklist of the mountain's vascular plants obtained through random-walk field excursions and retrieval of herbarium specimen tracing back to 1900. We compiled 1709 species from 673 genera in 131 families. One new species of the family Cucurbitaceae was also reported. This checklist records respective habitat, habits, elevation ranges, voucher numbers and global distribution ranges of each species. Native and exotic species were also distinguished, where 8.4% of the total species in 49 families were exotic species. There were 103 endemic species, while 14 species were found to be both rare and endemic. IUCN conservation status revealed 2 Critically Endangered, 4 Endangered, 9 Vulnerable and 2 Near Threatened species. This study presents the first and most comprehensive plant inventory of Mt Elgon that will facilitate further ecological and phylogenetic studies.

The complete chloroplast genome sequence of Trapa kozhevnikoviorum Pshenn. (Lythraceae).

Trapa (Lythraceae) is an economically important aquatic genus used for food and medicine, with wide distribution in Asia, Africa, and Europe. Identification of species, genetic studies and utilization of Trapa are limited by lack of molecular data. Herein, we report the complete chloroplast (cp) genome sequence of a wild species, Trapa kozhevnikoviorum Pshenn. The cp genome size of T. kozhevnikoviorum is 155,545 bp, consisting of a pair of inverted repeat regions (IRa/IRb) of length 24,388 bp, separated by the small single copy (SSC) region of 18,275 bp and a large single copy (LSC) region of 88,494 bp. A total of 113 unique genes, including 79 protein-coding, 30 tRNA, and four rRNA were annotated. Phylogenetic analysis based on 15 whole cp genomes of Lythraceae species supported the monophyletic clustering of Trapa. A cladal relationship among T. kozhevnikoviorum, T. bicornis, and T. natans was revealed.