Efficacy of rhizobacteria Paenibacillus polymyxa SY42 for the biological control of Atractylodes chinensis root rot.

Atractylodes chinensis is one of the most commonly used bulk herbs in East Asia; however, root rot can seriously affect its quality and yields. In contrast to chemical pesticides, biological control strategies are environmentally compatible and safe. For this study, 68 antagonistic bacterial strains were isolated from the rhizospheres of healthy Atractylodes chinensis. Strain SY42 exhibited the most potent fungicidal activities, with inhibition rates against F. oxysporum, F. solani, and F. redolens of 67.07 %, 63.40 % and 68.45 %, respectively. Through morphological observation and molecular characterization, strain SY42 was identified as Paenibacillus polymyxa. The volatile organic components (VOCs) produced by SY42 effectively inhibited the mycelial growth of pathogenic fungi through diffusion. SY42 significantly inhibited the germination of pathogenic fungal spores. Following co-culturing with SY42, the mycelium of the pathogenic fungus was deformed, folded, and even ruptured. SY42 could produce cellulases and proteases to degrade fungal cell walls. Pot experiments demonstrated the excellent biocontrol efficacy of SY42. This study revealed that P. polymyxa SY42 inhibited pathogenic fungi through multiple mechanisms, which verified its utility as a biocontrol agent for the control of A. chinensis root rot.

Integrative analysis of transcriptome and metabolome reveals the sesquiterpenoids and polyacetylenes biosynthesis regulation in Atractylodes lancea (Thunb.) DC.

Atractylodes lancea (Thunb.) is a perennial medicinal herb, with its dry rhizomes are rich in various sesquiterpenoids and polyacetylenes components (including atractylodin, atractylon and ß-eudesmol). However, the contents of these compounds are various and germplasms specific, and the mechanisms of biosynthesis in A. lancea are still unknown. In this study, we identified the differentially expressed candidate genes and metabolites involved in the biosynthesis of sesquiterpenoids and polyacetylenes, and speculated the anabolic pathways of these pharmaceutical components by transcriptome and metabolomic analysis. In the sesquiterpenoids biosynthesis, a total of 28 differentially expressed genes (DEGs) and 6 differentially expressed metabolites (DEMs) were identified. The beta-Selinene is likely to play a role in the synthesis of atractylon and ß-eudesmol. Additionally, the polyacetylenes biosynthesis showed the presence of 3 DEGs and 4 DEMs. Notably, some fatty acid desaturase (FAB2 and FAD2) significantly down-regulated in polyacetylenes biosynthesis. The gamma-Linolenic acid is likely involved in the biosynthesis of polyacetylenes and thus further synthesis of atractylodin. Overall, these studies have investigated the biosynthetic pathways of atractylodin, atractylon and ß-eudesmol in A. lancea for the first time, and present potential new anchor points for further exploration of sesquiterpenoids and polyacetylenes compound biosynthesis pathways in A. lancea.

The chloroplast genome of Amygdalus L. (Rosaceae) reveals the phylogenetic relationship and divergence time.

BACKGROUND: Limited access to genetic information has greatly hindered our understanding of the molecular evolution, phylogeny, and differentiation time of subg. Amygdalus. This study reported complete chloroplast (cp) genome sequences of subg. Amygdalus, which further enriched the available valuable resources of complete cp genomes of higher plants and deepened our understanding of the divergence time and phylogenetic relationships of subg. Amygdalus. RESULTS: The results showed that subg. Amygdalus species exhibited a tetrad structure with sizes ranging from 157,736 bp (P. kansuensis) to 158,971 bp (P. davidiana), a pair of inverted repeat regions (IRa/IRb) that ranged from 26,137-26,467 bp, a large single-copy region that ranged from 85,757-86,608 bp, and a small single-copy region that ranged from 19,020-19,133 bp. The average GC content of the complete cp genomes in the 12 species was 36.80%. We found that the structure of the subg. Amygdalus complete cp genomes was highly conserved, and the 12 subg. Amygdalus species had an rps19 pseudogene. There was not rearrangement of the complete cp genome in the 12 subg. Amygdalus species. All 12 subg. Amygdalus species clustered into one clade based on both Bayesian inference and maximum likelihood. The divergence time analyses based on the complete cp genome sequences showed that subg. Amygdalus species diverged approximately 15.65 Mya. CONCLUSION: Our results provide data on the genomic structure of subg. Amygdalus and elucidates their phylogenetic relationships and divergence time.

[Potential geographical distribution and changes of Artemisia ordosica in China under future climate change]. / 未来气候变化下黑沙蒿在中国的潜在地理分布及变迁.

Artemisia ordosica is a forerunner species of wind-break and sand-fixation in desert steppe in China, which plays an important role in ecosystem restoration and reconstruction. How-ever, it could influence human health. Based on 89 valid data of current distribution of A. ordosica in China and 19 typical climatic factors, the MaxEnt model was used to simulate the potential distribution of A. ordosica in China under current and two scenarios (RCP 4.5 and RCP 8.5; 2050s and 2070s). The SDM toolbox of ArcGIS software was used to analyze the potential distribution range of A. ordosica and its changes in China. The importance of key climatic factors was evaluated by comprehensive contribution rate, Jackknife method, and response curve of environmental variables. The accuracy of model was tested and evaluated by area under the curve (AUC) of the test subject working characteristic (ROC). The results showed that the MaxEnt model worked well (AUC=0.980). which predicted that A. ordosica was mainly concentrated in and around Mu Us Sandy Land, consistent with the current actual distribution range. The distribution area of A. ordosica of potential high fitness under the future two scenarios decreased by 5.2%-26.8%, which was negatively affected by future climate change. Seasonal variation of temperature, mean precipitation in the coldest season, and mean annual temperature had the greatest impact. The core area of future potential distribution of A. ordosica in China was located in Mu Us Sandy Land, with a tendency for spreading to northeast (Jilin, Heilongjiang, Liaoning and some parts of Hebei).

[Comparison of complete chloroplast genome sequences of Amygdalus pedunculata Pall.]

Amygdalus pedunculata Pall. is one of the 12 important woody oil crops in China. In this study, we determined the complete chloroplast genome sequence of A. pedunculata Pall. (MG602257) from Mu Us desert in Yulin city, Shaanxi province, China. The plastome was 157 851 bp with 36.8% GC content. Comparisons among the plastomes of MG602257 and other two MG869261 and KY101153 from Genebank of NCBI showed that the total length of these chloroplast genomes was MG602257< MG869261

The complete chloroplast genome sequence of Viola prionantha (Violaceae).

Viola Prionantha belongs to the family Violaceae. It has been widely used for a traditional Chinese herb with antibacterial activity and is grown as an early spring ornamental species in China. In this study, we determined the complete chloroplast genome sequence of V. prionantha which forms a circular structure. The whole chloroplast genome was 156,501 bp in length, consisting of a pair of inverted repeats (IR) of 26,404 bp, a large single-copy (LSC) region of 85,689 bp, and a small single-copy (SSC) region of 18,004 bp. We annotated 131 genes, including 84 coding sequences, 8 rRNA sequences, 37 tRNA sequences and 2 pesudogenes. Among the annotated genes, 17 genes contained one or two introns. Furthermore, a phylogenetic analysis revealed that V. prionantha and V. seoulensis clustered together as sisters to other Violaceae species.

The complete chloroplast genome sequence of Viola prionantha (Violaceae).

Viola prionantha belongs to the family Violaceae. It has been widely used for a traditional Chinese herb in China. We determined the complete chloroplast genome sequence of V. prionantha. The whole chloroplast genome was 156,501 bp in length, consisting of a pair of inverted repeats (IR) of 26,404 bp, each, a large single-copy (LSC) region of 85,689 bp, and a small single-copy (SSC) region of 18,004 bp. We annotated 131 genes, including 84 coding sequences, 8 rRNA sequences, 37 tRNA sequences, and 2 pesudogenes. Among the annotated genes Phylogenetic analysis revealed that V. prionantha and Viola seoulensis clustered together as sisters.

A repeat region from the Brassica juncea HMA4 gene BjHMA4R is specifically involved in Cd2+ binding in the cytosol under low heavy metal concentrations.

BACKGROUND: HMA4 transporters are involved in the transport and binding of divalent heavy metals (Cd, Zn, Pb [lead] and Co [cobalt]). In general, as efflux pumps, HMA4 transporters can increase the heavy metal tolerance of yeast and Escherichia coli. Additional research has shown that the C-terminus of HMA4 contains a heavy metal-binding domain and that heterologous expression of a portion of peptides from this C-terminal domain in yeast provides a high level of Cd tolerance and Cd hyperaccumulation. RESULTS: We cloned BjHMA4 from Brassica juncea, and quantitative real-time PCR analysis revealed that BjHMA4 was upregulated by Zn and Cd in the roots, stems and leaves. Overexpression of BjHMA4 dramatically affects Zn/Cd distribution in rice and wheat seedlings. Interestingly, BjHMA4 contains a repeat region named BjHMA4R within the C-terminal region; this repeat region is not far from the last transmembrane domain. We further characterized the detailed function of BjHMA4R via yeast and E. coli experiments. Notably, BjHMA4R greatly and specifically improved Cd tolerance, and BjHMA4R transformants both grew on solid media that contained 500 µM CdCl2 and presented improved Cd accumulation (approximately twice that of wild-type [WT] strains). Additionally, visualization via fluorescence microscopy indicated that BjHMA4R clearly localizes in the cytosol of yeast. Overall, these findings suggest that BjHMA4R specifically improves Cd tolerance and Cd accumulation in yeast by specifically binding Cd2+ in the cytosol under low heavy metal concentrations. Moreover, similar results in E. coli experiments corroborate this postulation. CONCLUSION: BjHMA4R can specifically bind Cd2+ in the cytosol, thereby substantially and specifically improving Cd tolerance and accumulation under low heavy metal concentrations.

Complete chloroplast genome sequence of the Amygdalus Nana.

Amygdalus nana is the research materials, and we used the Illumina HiSeq X Ten system to do sequencing, and used the complete chloroplast genomes of 12 species to constructed thephylogenetic tree. The results showed that the complete chloroplast genome of the A. nana was 158,596 bp in length, containing a largen single copy (LSC) region of 86,608 bp, a small single copy (SSC) region of 18,998 bp, and a pair of inverted repeats (IRs) region of 26,411 bp. The genome has a GC content of 36.7%. The LSC, SSC, and IR regions represent 54.61, 11.98, and 33.31% of the A. nana chloroplast genome length respectively. We annotated 130 genes, including 85 protein coding genes, 8 rRNA genes, and 37 tRNA genes. And the phylogenetic analysis suggested that the A. nana is closely related to A. mongolica.

The complete chloroplast genome sequence of Tribulus terrestris, an important traditional Chinese medicine.

Tribulus terrestris is an important traditional medicine in China, which is widely distributed in north China. Here, the chloroplast genome sequences were detected. The chloroplast genome of T. terrestris is circular-mapping molecule of 158,184 bp in size, which consisted of a pair of inverted repeat regions of 25,842 bp each, a large single copy region of 88,878 bp, and a small single copy region of 17,622 bp. A total of 129 genes were annotated, including 37 tRNA, 8 rRNA, and 84 protein-coding genes. Phylogenetic analysis showed T. terrestris clustered with Krameria lanceolate and Krameria bicolor.

The complete chloroplast genome of the Amygdalus ferganensis (Rosaceae) in Xinjiang, China.

Amygdalus ferganensis is a member of the family Rosaceae. In this paper, we report complete chloroplast genome sequences of A. ferganensis (Rosaceae). The results showed that A. ferganensis complete chloroplast genome comprises 158,365 bp, containing a largen single copy (LSC) region of 86,240 bp, a small single copy (SSC) region of 19,012 bp, and a pair of inverted repeats (IRs) region of 26,386 bp. The genome has a GC content of 42.6%. The LSC, SSC, and IR regions represent 54.46, 12.01, and 33.32% of the A. ferganensis chloroplast genome length. We annotated 112 genes, including 78 protein coding genes, 4 rRNAs, and 30 tRNAs. And A. ferganensis is closely the A. persica.

Clinical malaria along the China-Myanmar border, Yunnan Province, China, January 2011-August 2012.

Passive surveillance for malaria cases was conducted in Yunnan Province, China, along the China-Myanmar border. Infection with Plasmodium vivax and P. falciparum protozoa accounted for 69% and 28% of the cases, respectively. Most patients were adult men. Cross-border travel into Myanmar was a key risk factor for P. falciparum malaria in China.