Artemisia selengenesis is not only a health food, but also a well-known traditional Chinese medicine. Only a fraction of the chloroplast (cp) genome data of Artemisia has been reported and chloroplast genomic materials have been widely used in genomic evolution studies, molecular marker development, and phylogenetic analysis of the genus Artemisia, which makes evolutionary studies, genetic improvement, and phylogenetic identification very difficult. In this study, the complete chloroplast genome of A. selengensis was compared with that of other species within Artemisia and phylogenetic analyses was conducted with other genera in the Asteraceae family. The results showed that A. selengensis is an AT-rich species and has a typical quadripartite structure that is 151,215 bp in length. Comparative genome analyses demonstrated that the available chloroplast genomes of species of Artemisia were well conserved in terms of genomic length, GC contents, and gene organization and order. However, some differences, which may indicate evolutionary events, were found, such as a re-inversion event within the Artemisia genus, an unequal duplicate phenomenon of the ycf1 gene because of the expansion and contraction of the IR region, and the fast-evolving regions. Repeated sequences analysis showed that Artemisia chloroplast genomes presented a highly similar pattern of SSR or LDR distribution. A total of 257 SSRs and 42 LDRs were identified in the A. selengensis chloroplast genome. The phylogenetic analysis showed that A. selengensis was sister to A. gmelinii. The findings of this study will be valuable in further studies to understand the genetic diversity and evolutionary history of Asteraceae.
[Zhao, Yunlin; Xu, Zhenggang; Peng, Jiao] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, 498 Shaoshan South Rd, Changsha 410004, Hunan, Peoples R China.;[Xu, Zhenggang; Dong, Meng] Hunan City Univ, Coll Chem & Environm Engn, 518 Yingbin Rd, Yiyang 413000, Hunan, Peoples R China.;[Ge, Yu] Hubei Univ Nationalities, Coll Forestry, 39 Xueyuan Rd, Enshi 445000, Hubei, Peoples R China.;[Yang, Guiyan] Northwest A&F Univ, Coll Forestry, Lab Walnut Res Ctr, Yangling 712100, Shaanxi, Peoples R China.
[Yang, Guiyan] N;Northwest A&F Univ, Coll Forestry, Lab Walnut Res Ctr, Yangling 712100, Shaanxi, Peoples R China.
Juglans regia;Osmotic tolerance;ROS scavenger;V-ATPase G subunit
JrVHAG1 is an important candidate gene for plant osmotic tolerance regulation. Vacuolar H+-ATPase (V-ATPase) is important for plant responses to abiotic stress; the G subunit is a vital part of V-ATPase. In this study, a G subunit of V-ATPase was cloned from Juglans regia (JrVHAG1) and functionally characterized. JrVHAG1 transcription was induced by mannitol that increasing 17.88-fold in the root at 12 h and 19.16-fold in the leaf at 96 h compared to that under control conditions. JrVHAG1 was overexpressed in Arabidopsis and three lines (G2, G6, and G9) with highest expression levels were selected for analysis. The results showed that under normal conditions, the transgenic and wild-type (WT) plants displayed similar germination, biomass accumulation, reactive oxygen species (ROS) level, and physiological index. However, when treated with mannitol, the fresh weight, root length, water-holding ability, and V-ATPase, superoxide dismutase, and peroxidase activity of G2, G6, and G9 were significantly higher than those of WT. In contrast, the ROS and cell damage levels of the transgenic seedlings were lower than those of WT. Furthermore, the transcription levels of V-ATPase subunits, ABF, DREB, and NAC transcription factors (TFs), all of which are factors of ABA signaling pathway, were much higher in JrVHAG1 transgenic plants than those in WT. The positive induction of JrVHAG1 gene under abscisic acid (ABA) treatments in root and leaf tissues indicates that overexpression of JrVHAG1 improves plant tolerance to osmotic stress relating to the ABA signaling pathway, which is transcriptionally activated by ABF, DREB, and NAC TFs, and correlated to ROS scavenging and V-ATPase activity.
Microorganisms play a significant part in detoxifying and immobilizing excessive metals. The present research isolated a strain (HM7) with high Mn(II) tolerance from Mn(II)-contaminated soil samples. The 16S rDNA sequence analysis showed that HM7 had a 99% similarity to Bacillus thuringiensis, which can survive under a high concentration 4,000 mg/L of Mn(II), and the highest removal rate was up to 95.04% at the concentration of 400 mg/L. The highest Mn(II) removal rate was detected at the contact time 72 h, temperature 30 degrees C, and pH 5.0, while the differences in strain growth and Mn(II) removal rate among different inoculation doses were insignificant. Scanning electron microscopy indicated B. thuringiensis HM7 cells appeared irregular and cracked under Mn(II) stress. Fourier transform infrared exhibited that functional groups like carboxyl, hydroxyl, amino, sulfhydryl groups, and amide bands might take part in the complexation of Mn(II). In addition, HM7 suggested the ability of indoleacetic acid production, siderophore production, and P' solubilization potential. Therefore, HM7 might have a potential to promote metal absorption by changing the form of heavy metals, and the experiments supported the application of B. thuringiensis HM7 as a biological adsorbent in Mn(II) contaminated environment remediation.
BMC Ecology and Evolution,2021年21(1):1-17 ISSN：2730-7182
[Zhao, Yunlin; Xu, Zhenggang; Peng, Jiao] Cent South Univ Forestry & Technol, Hunan Res Ctr Engn Technol Utilizat Environm & Re, Changsha 410004, Hunan, Peoples R China.;[Zhong, Xiaofen; Zhao, Yunlin; Liu, Shiquan; Xu, Zhenggang; Dong, Meng; Hu, Zhiyuan; Peng, Jiao] Hunan City Univ, Hunan Prov Key Lab Dark Tea & Jin Hua, Yiyang 413000, Hunan, Peoples R China.;[Xu, Zhenggang] Northwest A&F Univ, Coll Forestry, Natl Forestry & Grassland Adm Management, Key Lab, Yangling 712100, Shaanxi, Peoples R China.
[Xu, Zhenggang] H;Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, 410004, Hunan, People's Republic of China.;Hunan Provincial Key Lab of Dark Tea and Jin-Hua, Hunan City University, Yiyang, 413000, Hunan, People's Republic of China.;Key Laboratory of National Forestry and Grassland Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A & F University, Yangling, 712100, Shaanxi, People's Republic of China.
BACKGROUND: Cultivated tea is one of the most important economic and ecological trees distributed worldwide. Cultivated tea suffer from long-term targeted selection of traits and overexploitation of habitats by human beings, which may have changed its genetic structure. The chloroplast is an organelle with a conserved cyclic genomic structure, and it can help us better understand the evolutionary relationship of Camellia plants. RESULTS: We conducted comparative and evolutionary analyses on cultivated tea and wild tea, and we detected the evolutionary characteristics of cultivated tea. The chloroplast genome sizes of cultivated tea were slightly different, ranging from 157,025 to 157,100 bp. In addition, the cultivated species were more conserved than the wild species, in terms of the genome length, gene number, gene arrangement and GC content. However, comparing Camellia sinensis var. sinensis and Camellia sinensis var. assamica with their cultivars, the IR length variation was approximately 20 bp and 30 bp, respectively. The nucleotide diversity of 14 sequences in cultivated tea was higher than that in wild tea. Detailed analysis on the genomic variation and evolution of Camellia sinensis var. sinensis cultivars revealed 67 single nucleotide polymorphisms (SNPs), 46 insertions/deletions (indels), and 16 protein coding genes with nucleotide substitutions, while Camellia sinensis var. assamica cultivars revealed 4 indels. In cultivated tea, the most variable gene was ycf1. The largest number of nucleotide substitutions, five amino acids exhibited site-specific selection, and a 9 bp sequence insertion were found in the Camellia sinensis var. sinensis cultivars. In addition, phylogenetic relationship in the ycf1 tree suggested that the ycf1 gene has diverged in cultivated tea. Because C. sinensis var. sinensis and its cultivated species were not tightly clustered. CONCLUSIONS: The cultivated species were more conserved than the wild species in terms of architecture and linear sequence order. The variation of the chloroplast genome in cultivated tea was mainly manifested in the nucleotide polymorphisms and sequence insertions. These results provided evidence regarding the influence of human activities on tea.
The complete chloroplast genome sequence of Lupinus westianus, an endangered and endemic species to Florida, United States, has been assembled from Illumina pair-end sequencing. The chloroplast genome structure of L. westianus is a circular molecule of 154,270 bp in length, with a large single copy (LSC) region of 82,437 bp, a small single copy (SSC) region of 15,853 bp, and a pair of inverted repeats (IRs) regions of 27,990 bp. The total G+C content of chloroplast genome is 36.47%, and while it is 41.56% of IRs, which was higher than LSC and SSC regions. The genome contained 130 genes, including 85 protein coding genes, 37 tRNA genes and 8 rRNA genes, of which 18 were duplicated in the IRs region. The phylogenetic analysis indicated that L. westianus was clustered together with other two genus of Lupinus, L. luteus and L. albus. The chloroplast genome of L. westianus laid a good foundation for genetic resoures conservation. The chloroplast genome reported provided useful genomic resources not only for the exchange of information between different species, but also for the population genetics of L. westianus and its phylogenetic and evolutionary studies.