https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.14907

A global database for plants that hyperaccumulate metal and metalloid trace elements.

Summary
Cadmium (Cd) is highly toxic to most organisms, but some rare plant species can hyperaccumulate Cd in aboveground tissues without suffering from toxicity. The mechanism underlying Cd detoxification by hyperaccumulators is interesting but unclear.
Here, the heavy metal ATPase 3 (SpHMA3) gene responsible for Cd detoxification was isolated from the Cd/zinc (Zn) hyperaccumulator Sedum plumbizincicola. RNA interference (RNAi)-mediated silencing and overexpression of SpHMA3 were induced to investigate its physiological functions in S. plumbizincicola and a nonhyperaccumulating ecotype of Sedum alfredii.
Heterologous expression of SpHMA3 in Saccharomyces cerevisiae showed Cd-specific transport activity. SpHMA3 was highly expressed in the shoots and the protein was localized to the tonoplast. The SpHMA3-RNAi lines were hypersensitive to Cd but not to Zn, with the growth of shoots and young leaves being severely inhibited by Cd. Overexpressing SpHMA3 in the nonhyperaccumulating ecotype of S. alfredii greatly increased its tolerance to and accumulation of Cd, but not Zn.
These results indicate that elevated expression of the tonoplast-localized SpHMA3 in the shoots plays an essential role in Cd detoxification, which contributes to the maintenance of the normal growth of young leaves of S. plumbizincicola in Cd-contaminated soils.

https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.14622

Heavy metal ATPase 3 (HMA3) confers cadmium hypertolerance on the cadmium/zinc hyperaccumulator Sedum plumbizincicola

Hyperaccumulator plants are the material basis for phytoextraction research and for practical applications in decontaminating polluted soils and industrial wastes. China's high biodiversity and substantial mineral resources make it a global hotspot for hyperaccumulator plant species. Intensive screening efforts over the past 20 years by researchers working in China have led to the discovery of many different hyperaccumulators for a range of elements. In this review, we present the state of knowledge on all currently reported hyperaccumulator species from China, including Cardamine hupingshanensis (selenium, Se), Dicranopteris dichotoma (rare earth elements, REEs), Elsholtzia splendens (copper, Cu), Phytolacca americana (manganese, Mn), Pteris vittata (arsenic, As), Sedum alfredii, and Sedum plumbizincicola (cadmium/zinc, Cd/Zn). This review covers aspects of the ecophysiology and molecular biology of tolerance and hyperaccumulation for each element. The major scientific advances resulting from the study of hyperaccumulator plants in China are summarized and synthesized.

/pdf/hyperaccumulator-plants-from-china-a-synthesis-of-the-3ms49gcbdd.pdf

Hyperaccumulator Plants from China: A Synthesis of the Current State of Knowledge.

八宝属（Crassulaceae）一新变种

Bamboo - An untapped plant resource for the phytoremediation of heavy metal contaminated soils.

Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae), a new species restricted to lead–zinc mining areas in Zhejiang Province, China, is described and illustrated. This taxon belongs to sect. Sedum (H. Ohba) S.H. Fu based on the adaxially gibbous carpels and follicles. It superficially resembles S. alfredii Hance and three other Sedum species found in the same area, but differs from these other taxa in bearing 4-merous flowers. Differences in geographical distribution, growth habit, phenology, macromorphology, leaf and stem anatomy, as well as seed micromorphology among S. plumbizincicola, S. alfredii and other related taxa in the genus Sedum are also reported. nrDNA internal transcribed spacers (ITS) sequences from seven populations of S. plumbizincicola support the recognition of this as a taxonomic entity distinct from S. alfredii.

/pdf/sedum-plumbizincicola-x-h-guo-et-s-b-zhou-ex-l-h-wu-4skmiz03jc.pdf

Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae): a new species from Zhejiang Province, China

Plastome evolution of Aeonium and Monanthes (Crassulaceae): insights into the variation of plastomic tRNAs, and the patterns of codon usage and aversion

Simple Summary Mitochondria are semiautonomous organelles in eukaryotic cells, which play a critical role in cellular energy production. The plant mitochondrial genomes harbor large degrees of variation and complexity in structures. Crassulaceae is the largest family in the order Saxifragales. However, no entire mitogenome data have been available for species of Crassulaceae up to now. In the present study, we sequenced the first mitogenome of Crassulaceae (presented by Sedum plumbizincicola). Through comprehensive analyses, we found Saxifragales mitogenomes have undergone rapid structural evolution, with low synonymous substitution rates. Moreover, RNA editing, gene transfer, secondary structures of mitochondrial RNAs, and phylogenetic implications were also analyzed by using mitochondrial data. The present work may provide new insights into the mitogenome evolution of Saxifragales. Abstract As the largest family within the order Saxifragales, Crassulaceae contains about 34 genera with 1400 species. Mitochondria play a critical role in cellular energy production. Since the first land plant mitogenome was reported in Arabidopsis, more than 400 mitogenomic sequences have been deposited in a public database. However, no entire mitogenome data have been available for species of Crassulaceae to date. To better understand the evolutionary history of the organelles of Crassulaceae, we sequenced and performed comprehensive analyses on the mitogenome of Sedum plumbizincicola. The master mitogenomic circle is 212,159 bp in length, including 31 protein-coding genes (PCGs), 14 tRNA genes, and 3 rRNA genes. We further identified totally 508 RNA editing sites in PCGs, and demonstrated that the second codon positions of mitochondrial genes are most prone to RNA editing events. Notably, by neutrality plot analyses, we observed that the mitochondrial RNA editing events have large effects on the driving forces of plant evolution. Additionally, 4 MTPTs and 686 NUMTs were detected in the mitochondrial and nuclear genomes of S. plumbizincicola, respectively. Additionally, we conducted further analyses on gene transfer, secondary structures of mitochondrial RNAs, and phylogenetic implications. Therefore, the findings presented here will be helpful for future investigations on plant mitogenomes.

/pdf/the-mitogenome-of-sedum-plumbizincicola-crassulaceae-2v8t49lz.pdf

The Mitogenome of Sedum plumbizincicola (Crassulaceae): Insights into RNA Editing, Lateral Gene Transfer, and Phylogenetic Implications

Simple Summary Plastids are semi-autonomous plant organelles which play critical roles in photosynthesis, stress response, and storage. The plastid genomes (plastomes) in angiosperms are relatively conserved in quadripartite structure, but variable in size, gene content, and evolutionary rates of genes. The genus Crassula L. is the second-largest genus in the family Crassulaceae J.St.-Hil, that significantly contributes to the diversity of Crassulaceae. However, few studies have focused on the evolution of plastomes within Crassula. In the present study, we sequenced ten plastomes of Crassula: C. alstonii Marloth, C. columella Marloth & Schönland, C. dejecta Jacq., C. deltoidei Thunb., C. expansa subsp. fragilis (Baker) Toelken, C. mesembrianthemopsis Dinter, C. mesembryanthoides (Haw.) D.Dietr., C. socialis Schönland, C. tecta Thunb., and C. volkensii Engl. Through comparative studies, we found Crassula plastomes have unique codon usage and aversion patterns within Crassulaceae. In addition, genomic features, evolutionary rates, and phylogenetic implications were analyzed using plastome data. Our findings will not only reveal new insights into the plastome evolution of Crassulaceae, but also provide potential molecular markers for DNA barcoding. Abstract The genus Crassula is the second-largest genus in the family Crassulaceae, with about 200 species. As an acknowledged super-barcode, plastomes have been extensively utilized for plant evolutionary studies. Here, we first report 10 new plastomes of Crassula. We further focused on the structural characterizations, codon usage, aversion patterns, and evolutionary rates of plastomes. The IR junction patterns—IRb had 110 bp expansion to rps19—were conservative among Crassula species. Interestingly, we found the codon usage patterns of matK gene in Crassula species are unique among Crassulaceae species with elevated ENC values. Furthermore, subgenus Crassula species have specific GC-biases in the matK gene. In addition, the codon aversion motifs from matK, pafI, and rpl22 contained phylogenetic implications within Crassula. The evolutionary rates analyses indicated all plastid genes of Crassulaceae were under the purifying selection. Among plastid genes, ycf1 and ycf2 were the most rapidly evolving genes, whereas psaC was the most conserved gene. Additionally, our phylogenetic analyses strongly supported that Crassula is sister to all other Crassulaceae species. Our findings will be useful for further evolutionary studies within the Crassula and Crassulaceae.

/pdf/ten-plastomes-of-crassula-crassulaceae-and-phylogenetic-2a6ycxgo.pdf

Ten Plastomes of Crassula (Crassulaceae) and Phylogenetic Implications

Simple Summary The mitochondrial genome (mitogenome) recently has been extensively used in evolutionary analyses. The superfamily Certhioidea is a highly diverse group within the passerine clade, and the phylogeny of this group is still controversial. To date, few studies have focused on the mitogenome evolution of Certhioidea. In the present study, we provided six new complete mitogenomes of Certhioidea. Comprehensive analyses were carried out on the mitogenomes of Certhioidea, including basic genomic characteristics, codon usage patterns, evolutionary rates, and phylogenetic implications. Based on our analyses, we found the codon usage biases of genes were asymmetrical. Most importantly, we suggested that Salpornis should be separated from family Certhiidae and put into family Salpornithidae to maintain the monophyly of Certhiidae. The present work may provide new insights on the mitogenome evolution of Certhioidea. Abstract The superfamily Certhioidea currently comprises five families. Due to the rapid diversification, the phylogeny of Certhioidea is still controversial. The advent of next generation sequencing provides a unique opportunity for a mitogenome-wide study. Here, we first provided six new complete mitogenomes of Certhioidea (Certhia americana, C. familiaris, Salpornis spilonota, Cantorchilus leucotis, Pheugopedius coraya, and Pheugopedius genibarbis). We further paid attention to the genomic characteristics, codon usages, evolutionary rates, and phylogeny of the Certhioidea mitogenomes. All mitogenomes we analyzed displayed typical ancestral avian gene order with 13 protein-coding genes (PCGs), 22 tRNAs, 2 rRNAs, and one control region (CR). Our study indicated the strand-biased compositional asymmetry might shape codon usage preferences in mitochondrial genes. In addition, natural selection might be the main factor in shaping the codon usages of genes. Additionally, evolutionary rate analyses indicated all mitochondrial genes were under purifying selection. Moreover, MT-ATP8 and MT-CO1 were the most rapidly evolving gene and conserved genes, respectively. According to our mitophylogenetic analyses, the monophylies of Troglodytidae and Sittidae were strongly supported. Importantly, we suggest that Salpornis should be separated from Certhiidae and put into Salpornithidae to maintain the monophyly of Certhiidae. Our findings are useful for further evolutionary studies within Certhioidea.

https://www.mdpi.com/2076-2615/13/1/96/pdf?version=1672122713

D. Bi

Papers

Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae): a new species from Zhejiang Province, China

Plastome evolution of Aeonium and Monanthes (Crassulaceae): insights into the variation of plastomic tRNAs, and the patterns of codon usage and aversion

The Mitogenome of Sedum plumbizincicola (Crassulaceae): Insights into RNA Editing, Lateral Gene Transfer, and Phylogenetic Implications

Ten Plastomes of Crassula (Crassulaceae) and Phylogenetic Implications

Mitogenomic Codon Usage Patterns of Superfamily Certhioidea (Aves, Passeriformes): Insights into Asymmetrical Bias and Phylogenetic Implications