We sequenced and analyzed the complete chloroplast genome of Aster tataricus (family Asteraceae), a Chinese herb used medicinally to relieve coughs and reduce sputum. The A. tataricus chloroplast genome was 152,992 bp in size, and harbored a pair of inverted repeat regions (IRa and IRb, each 24,850 bp) divided into a large single-copy (LSC, 84,698 bp) and a small single-copy (SSC, 18,250 bp) region. Our annotation revealed that the A. tataricus chloroplast genome contained 115 genes, including 81 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. In addition, 70 simple sequence repeats (SSRs) were detected in the A. tataricus chloroplast genome, including mononucleotides (36), dinucleotides (1), trinucleotides (23), tetranucleotides (1), pentanucleotides (8), and hexanucleotides (1). Comparative chloroplast genome analysis of three Aster species indicated that a higher similarity was preserved in the IR regions than in the LSC and SSC regions, and that the differences in the degree of preservation were slighter between A. tataricus and A. altaicus than between A. tataricus and A. spathulifolius. Phylogenetic analysis revealed that A. tataricus was more closely related to A. altaicus than to A. spathulifolius. Our findings offer valuable information for future research on Aster species identification and selective breeding.

Background: Ligusticum chuanxiong Hort. is a well-known traditional Chinese medicinal herb whose clinical application and international trade had been constrained by cadmium (Cd) contamination. However, the molecular mechanisms underlying its response to cadmium stress remained poorly understood. The ATP-binding cassette (ABC) transporter family plays crucial roles in various plant processes, including growth and development, hormone transduction, and stress responses. This study aimed to analyze the ABC transporter genes in L. chuanxiong to better understand their roles during cadmium stress responses. Methods: Genome-wide identification of ABC genes in L. chuanxiong was performed, and transcriptome sequencing of rhizomes under cadmium stress was conducted. Differentially expressed LcABC genes were screened using bioinformatic analysis. Results: A total of 368 LcABC genes were identified. Transcriptome analysis revealed 37 upregulated LcABC genes, which were classified into six subfamilies. Cis-element analysis indicated that their promoters contain hormone-, growth-, and stress-responsive elements. Notably, LcABCG8, LcABCG48, and LcABCG108 contain stress-responsive elements and show close evolutionary relationships with heavy metal-responsive genes such as AtABCC1/2/3 and AtABCG36/40, suggesting that they could be key candidates. qRT-PCR validation of nine LcABC genes confirmed their differential sensitivity to cadmium stress. Conclusions: This study conducted a comprehensive identification of the ABC gene family in L. chuanxiong. By integrating transcriptomic data with systematic bioinformatic analyses, we identified several LcABC transporters that may play important roles in cadmium stress responses. The results provide insights into the molecular mechanisms of ABC transporters in cadmium stress responses in L. chuanxiong and offer strategies for reducing cadmium accumulation.

Magnolia officinalis, M. officinalis subsp.biloba and M. hypoleuca are all typical medicinal plants, belonging to genus Magnolia and Family Magnoliaceae. Their molecular information, particularly genetic difference, were known less. In this study, the platform Illumina HiSeq was used to sequence and assemble a novel cp (chloroplast) genome of M. hypoleuca followed by cp purification. Combined with two published cp rawdata, gene cycles and function annotations were comparably performed for the three plant species. The results indicated that 19 791 019 clean reads was assembled for M. hypoleuca cp, Q30 being 91.33%, and genome 160 051 bp. Its GC content is 39.2%, including 37 tRNAs and 8 rRNAs. The M. hypoleuca had smaller chloroplast genome and more introns (or exons) than M. officinalis and M. officinalis subsp.biloba. And there were respectively 11 and 8 more functional genes in M. hypoleuca cp than that in the other two. Based on cp complete genomes sequences, we constructed the phylogenetic relationship and estimated the divergence time of the three species by ML (Maximum likelihood) method, with other 10 published Magnoliaceae species. The results showed that M. officinalis subsp.biloba and M. officinalis might diverge from M. hypoleuca around 18.98 Ma, then they diverged from each other around 15.00 Ma. Additionally, the middle Miocene warming period might play an important role in the demographic and evolutionary histories of the three Magnolias, which provided a novel insight of the origin and dispersal routes of M. hypoleuca.

To overcome the risk of cellular damage and RNA degradation caused by high temperatures and cellular damage induced by laser capture microdissection (LCM) during plant single cell or small cell cluster isolation, we developed a rapid and simple method for single-cell separation and trace RNA extraction. The extracted RNA can be used for Smart-seq analysis, enabling comprehensive studies of various cell types. We used the secretory cells of Ligusticum chuanxiong Hort. fibrous root. First, we performed paraffin embedding to maintain RNA stability, and then examined the optimal slice thickness to obtain intact secretory cells. We compared the RNA quality of secretory cells isolated by LCM versus manual dissection under a microscope with a scalpel. Finally, xylene was introduced into the lysis buffer, followed by rapid shaking to achieve simultaneous dewaxing and cell lysis, and the xylene layer was then removed by centrifugation. A slice thickness of 20 μ m best preserved the integrity of secretory cells. Compared with LCM, this method yielded higher quality RNA. The obtained transcriptomic data showed an average Q30 score exceeding 91% and a genome mapping rate surpassing 86%. This method can yield high-quality trace RNA suitable for Smart-seq analysis. Moreover, the significant differences in the transcriptomes of various small cell clusters types demonstrate the effectiveness and specificity of our manual dissection method.

Ligusticum chuanxiong Hort. is a renowned genuine medicinal material from Sichuan with significant medicinal value. However, the lack of an efficient tissu