Salvianolic acids represent the predominant phenolic compounds in Salvia miltiorrhiza Bunge, a medicinal herb widely applied in cardiovascular and cerebrovascular therapies. Despite their pharmacological relevance, the transcriptional mechanisms controlling salvianolic acids production remain incompletely understood. Among potential regulators, WRKY is well known in modulating plant development, secondary metabolism, and stress adaptation, yet to be systematically characterized in relation to SmWRKY gene involvement in salvianolic acids biosynthesis. Here, abscisic acid (ABA) was found to enhance salvianolic acids accumulation in leaves and tanshinone ⅡA in roots of S. miltiorrhiza. Transcriptome analysis of ABA- and PEG6000-treated plants identified SmWRKY20 as a candidate transcription factor (TF) associated with salvianolic acids biosynthesis, as determined through co-expression analysis. SmWRKY20 was predominantly observed and strong responsiveness to ABA in the roots. In transgenic hairy roots, SmWRKY20-OE dramatically enhanced rosmarinic acid and salvianolic acid B levels, whereas RNAi suppression led to their marked reduction. Correspondingly, upregulated and downregulated SmC4H1 expression occurred in OE and RNAi lines, respectively. Dual-LUC, EMSA, together with Y1H experiments showed that SmWRKY20 directly binds to W-box1/2 elements in SmC4H1 promoter, activating its expression. SmWRKY20 promotes the biosynthesis of salvianolic acids by activating SmC4H1. This work elucidates ABA-dependent regulatory metabolic mechanisms in S. miltiorrhiza, establishing a conceptual framework for optimizing growth strategies to improve medicinal root materials.

Tanshinones, the major bioactive diterpenes in Salvia miltiorrhiza Bunge, are widely used to treat cardiovascular and cerebrovascular diseases. While jasmonates (JAs) are known to modulate tanshinones accumulation, the molecular link between JA signalling and tanshinone biosynthesis remains unclear. Here, we identify SmWRKY33, a JA-responsive WRKY transcription factor, as a key regulator of tanshinone biosynthesis through multiomic and genetic analyses. SmWRKY33 is highly expressed in the roots of S. miltiorrhiza. SmWRKY33 directly binds to the promoters of SmCPS1, SmKSL1, SmCYP76AH3, SmCYP71D373 and Sm2-ODD14, activating their transcription and promoting tanshinones accumulation. Notably, SmWRKY33 interacts with SmJAZ8, a JA signalling repressor, which suppresses its transcriptional activity on tanshinone biosynthetic genes. Additionally, SmMPK3 is responsive to JA signaling and functions as a positive regulator of tanshinone biosynthesis in S. miltiorrhiza. Furthermore, SmMPK3 directly associates with and phosphorylates SmWRKY33, a modification that enhances its transcriptional activity and DNA-binding capacity. Collectively, our findings elucidate how JA signalling integrates with MAPK phosphorylation to regulate specialised metabolism and provide molecular targets for metabolic engineering to enhance tanshinones production in S. miltiorrhiza.

This study reveals the transcripts of S. miltiorrhiza in response to phosphate deficiency, identifies 18 SmPHRs in the genome, and tentatively establishes a role for SmPHR7 in regulating phosphate starvation. Phosphorus is essential for plant growth and development, and phosphate deficiency is a common nutritional stress. Salvia miltiorrhiza (Danshen) is a traditional Chinese herb whose main active medicinal secondary metabolite is used in the treatment of heart disease. However, the physiological and molecular effects of phosphate starvation in S. miltiorrhiza have not been well studied. Here, we first investigated the effect of phosphate starvation on the growth and major medicinal compounds. Biomass decreased with lower phosphate concentrations, while the accumulation of compounds varied in S. miltiorrhiza. Transcriptome analysis showed that phosphate starvation affected the expression of genes involved in processes such as glycolysis/gluconeogenesis, glycerolipid metabolism, and phenylpropanoid biosynthesis. Phosphate starvation response (PHR) transcription factors play an important role in the phosphate starvation response, and we identified 18 PHR family genes in S. miltiorrhiza, distributed across 8 chromosomes. The expression levels of different SmPHR family members in roots and shoots differ in response to phosphate starvation. SmPHR7, which is highly expressed in response to phosphate starvations, was selected for further functional characterization. SmPHR7 has transcriptional activation activity and is localized in the nucleus. Furthermore, the expression of SmPHR7 in the Arabidopsis thaliana mutant phr (SmPHR7-OX) is shown to partially rescue the phosphate starvation phenotype. The expression of the Pi starvation-induced (PSI) gene in SmPHR7-OX showed a significant induction compared to the phr mutant under phosphate starvation. The identification of the SmPHR gene family significantly contributes to a broader understanding of phosphate starvation signaling in S. miltiorrhiza.

Background Obtaining high-quality chloroplast genome sequences requires chloroplast DNA (cpDNA) samples that meet the sequencing requirements. The quality of extracted cpDNA directly impacts the efficiency and accuracy of sequencing analysis. Currently, there are no reported methods for extracting cpDNA from Erigeron breviscapus. Therefore, we developed a suitable method for extracting cpDNA from E. breviscapus and further verified its applicability to other medicinal plants.Results We conducted a comparative analysis of chloroplast isolation and cpDNA extraction using modified high-salt low-pH method, the high-salt method, and the NaOH low-salt method, respectively. Subsequently, the number of cpDNA copies relative to the nuclear DNA (nDNA ) was quantified via qPCR. As anticipated, chloroplasts isolated from E. breviscapus using the modified high-salt low-pH method exhibited intact structures with minimal cell debris. Moreover, the concentration, purity, and quality of E. breviscapus cpDNA extracted through this method surpassed those obtained from the other two methods. Furthermore, qPCR analysis confirmed that the modified high-salt low-pH method effectively minimized nDNA contamination in the extracted cpDNA. We then applied the developed modified high-salt low-pH method to other medicinal plant species, including Mentha haplocalyx, Taraxacum mongolicum, and Portulaca oleracea. The resultant effect on chloroplast isolation and cpDNA extraction further validated the generalizability and efficacy of this method across different plant species.Conclusions The modified high-salt low-pH method represents a reliable approach for obtaining high-quality cpDNA from E. breviscapus. Its universal applicability establishes a solid foundation for chloroplast genome sequencing and analysis of this species. Moreover, it serves as a benchmark for developing similar methods to extract chloroplast genomes from other medicinal plants.

Phosphorus is one of the three key nutrients, essential for plant growth and development, with phosphate deficiency posing a common nutritional stress. In the context of responding to low phosphorus stress, several members of the MYB-CC gene family are recognized for their crucial regulatory functions. However, there is a lack of prior research on the MYB-CC gene family and its function reported in Salvia miltiorrhiza. We identified 18 genes in S.miltiorrhiza, distributed across eight chromosomes. Evolutionary analysis showed that both fragment duplication and whole genome duplication (WGD) serve as the principal mechanisms driving the expansion of the SmMYB-CC gene family. The promoters of SmMYB-CC contain cis-acting elements associated with a range of physiological processes such as abiotic stress, hormone signaling as well as growth and development. Analyses of transcriptome data obtained from different phosphorus concentration treatments have indicated that the expression levels of the SmMYB-CC7 increase in both shoot and roots. Moreover, SmMYB-CC7 demonstrates transcriptional activation activity, and is localizes within the nucleus, with no apparent alterations in subcellular localization observed in the response to low phosphorus conditions. Furthermore, the expression of SmMYB-CC7 in the Arabidopsis thaliana mutant phr (SmMYB-CC7-GFP/phr) is shown to partially retain the phenotype under low phosphorus conditions. Under conditions of low phosphorus stress, the expression of Pi starvation-induced (PSI) gene in SmMYB-CC7-GFP/phr exhibited a significant induction compared to the phr mutant. The identification of the SmMYB-CC gene family and the validation of SmMYB-CC7 function contribute significantly to the broader understanding of phosphate starvation signaling in S.miltiorrhiza.

Salvia miltiorrhiza Bunge (Danshen) is a traditional Chinese herb with significant medicinal value. The yield and quality of Danshen are greatly affected by climatic conditions, in particular high temperatures. Heat shock factors (Hsfs) play important regulatory roles in plant response to heat and other environmental stresses. However, little is currently known about the role played by the Hsf gene family in S. miltiorrhiza. Here, we identified 35 SmHsf genes and classified them into three major groups: SmHsfA (n = 22), SmHsfB (n = 11), and SmHsfC (n = 2) using phylogenetic analysis. The gene structure and protein motifs were relatively conserved within subgroups but diverged among the different groups. The expansion of the SmHsf gene family was mainly driven by whole-genome/segmental and dispersed gene duplications. The expression profile of SmHsfs in four distinct organs revealed its members (23/35) are predominantly expressed in the root. The expression of a large number of SmHsfs was regulated by drought, ultraviolet, heat and exogenous hormones. Notably, the SmHsf1 and SmHsf7 genes in SmHsfB2 were the most responsive to heat and are conserved between dicots and monocots. Finally, heterologous expression analysis showed that SmHsf1 and SmHsf7 enhance thermotolerance in yeast. Our results provide a solid foundation for further functional investigation of SmHsfs in Danshen plants as a response to abiotic stresses.

为揭示小分子热激蛋白在丹参抵御逆境胁迫和有效成分积累的分子机制,根据橙根丹参转录组测序结果并结合RT-PCR技术在丹参中克隆获得一个小分子热激蛋白基因,其开放阅读框长度为585 bp,编码194个氨基酸,根据该基因编码的蛋白分子质量命名为SmHSP21.8.根据氨基酸多重序列比对和系统进化树分析,SmHSP21.8属于小分子热激蛋白的内质网亚族,并含有内质网小分子热激蛋白N端保守基序DPFR-I/V-LE-H/Q-x-P.构建原核表达载体pMAL-c2X-SmHSP21.8,并转化至大肠杆菌BL21感受态细胞,经诱导,成功表达出目的蛋白.时空表达分析表明,该基因在花中表达量最高,有显著的组织特异性.经38℃、PEG6000、脱落酸(abscisic acid,ABA)和吲哚-3-乙酸(indole-3-acetic acid,IAA)的诱导,该基因的相对表达量均有提高,表明SmHSP21.8参与了丹参幼苗对非生物胁迫高温、干旱,以及外源激素ABA和IAA响应的过程,为进一步研究小分子热激蛋白参与丹参响应逆境的分子机制奠定了基础.

The WRKY proteins, which represent one of the largest families of transcriptional regulators in plants, play pivotal roles in regulating multiple processes of growth and development, particularly in diverse stress responses. Isatis indigotica is widely used in Traditional Chinese Medicine and is famous for its use as a dye for the color indigo. However, reports of the WRKY gene family in I. indigotica are limited. In this study, 64 IiWRKY genes encoding proteins with the complete WRKY domain were identified from genome of I. indigotica. Based on their structure and phylogenetic relationships of this gene family in I. indigotica, the IiWRKY genes were classified into three groups: Group I (n = 13), Group II (n = 35) and Group III (n = 16). Sequence alignment revealed that IiWRKY proteins harbored two variants, WRKYRQK and WRKYGKK, of the highly conserved WRKYGQK motif. The number of exons in IiWRKY genes varied from two to 14, with most of IiWRKY genes containing three exons. Investigation of gene duplication demonstrated that 10 and 14 IiWRKY genes were incorporated in tandem and segmental duplication events, respectively. Finally, the expression profiles derived from transcriptome data and quantitative real-time PCR analysis showed distinct expression patterns of these IiWRKY gene in five different organs or in response to four abiotic stresses. Taken together, our results will contribute to functional analysis of IiWRKY genes, and also provide a basis for further clarification of the molecular mechanism of stress responses in this important herb.

Isatis indigotica Fort. is a popular herb in traditional Chinese medicine. It possesses pharmacological activities against various diseases, particularly leukemia. Indigoid alkaloids are its main bioactive ingredients. A relatively low nitrogen supply increases indigoid content in I. indigotica leaves, yet the mechanisms that regulate indigoid biosynthesis are unknown. To uncover regulatory mechanisms, we performed transcriptome sequencing of leaf samples from I. indigotica exposed to deficient (0 mM), low (7.5 mM), and high (15 mM) concentrations of NO3−. We generated 38,990 unigenes with an N50 value of 1923 bp, of which 33,007 unigenes (84.65%) were annotated in at least one database. In comparison with deficient N, we identified 6911 and 4845 differentially expressed genes (DEGs) in high N and low N. Cluster analysis of these DEGs showed a unique expression pattern in the N-supplied compared with the N-free condition. Twenty-one genes related to nitrogen uptake, transport, and assimilation were highly expressed in N-deficient conditions. Further, 63 putative genes that encode for enzymes involved in indigoid biosynthesis in I. indigotica leaf were identified and analyzed. Thirteen genes involved in indole modification were expressed more highly in low N; their high expression level may explain the increase in indigoid alkaloids in low N. Notably, phylogenetic analysis showed that IiTSA3 may relate to genes involved in indole heterocycle biosynthesis. Additionally, 491 differentially expressed TFs were also identified. Our findings will enrich gene resources for elucidating the molecular mechanisms of indigoid alkaloid biosynthesis in I. indigotica leaves under different nitrogen supplies.

为研究茶树凋落叶浸提液对菘蓝生长与生理生化的化感效应,以模拟自然条件下雨雾淋溶方式,采用不同浓度的茶树凋落叶浸提液(CK:0 mg·mL-1、T1:6.25 mg·mL-1、T2:12.5 mg·mL-1、T3:25mg·mL-1和T4:50 mg·mL-1)处理菘蓝,测定其生长、抗氧化酶活性及其基因表达量、细胞膜损伤率以及丙二醛(MDA)、过氧化氢(H202)、渗透调节物质和次生代谢物含量的变化.结果 表明,茶树凋落叶浸提液对菘蓝生长表现出“低促高抑”的浓度效应,与CK相比,T1对菘蓝生长具有一定的促进作用,而浸提液浓度超过菘蓝的耐受阈值时,会对其生长产生不利的影响.随着浸提液浓度的升高,可溶性糖和可溶性蛋白含量呈先上升后下降的趋势,而脯氨酸含量则持续增加.与CK相比,T1的MDA含量、细胞膜损伤率和H2O含量差异不显著,而T3、T4则显著升高.茶树凋落叶浸提液对抗氧化酶活性及其基因表达有不同的影响,T1的过氧化物酶(POD)与抗坏血酸氧化物酶(APX)活性最高,T2的过氧化氢酶(CAT)活性最高,而T3、T4的4种抗氧化酶活性均显著低于CK.T1的Pod、Cat、Apx基因表达量最高,而T4则抑制了抗氧化酶基因的表达.此外,POD活性与其基因表达量呈显著正相关,而超氧化物歧化酶(SOD)、CAT和APX活性与其基因表达量的相关性不显著.不同浓度的茶树凋落叶浸提液对于菘蓝次生代谢物质积累的影响存在显著差异,低浓度茶树凋落叶浸提液对菘蓝生长、靛蓝和靛玉红含量积累有促进作用,而高浓度茶树凋落叶浸提液对总黄酮含量积累有一定的促进作用.本研究结果可为幼龄茶园中茶树-菘蓝复合种植提供理论参考.

Isatis indigotica Fortune represents a significant economic resource in China, which the leaves (Daqingye) remain until now important and popular herbal drug in traditional Chinese medicine (TCM). Nitrogen nutrition is in great demand during plant growth stage, and nitrogen levels are usually related with plants biosynthesis of primary and secondary metabolites. To investigate the influence of nitrogen nutrition levels on various metabolites of Isatis leaf, untargeted metabolomics analysis based on LC-MS (UPLC-Triple-TOF system) was used to obtain the response of Isatis leaf under different nitrogen levels: 0 mmol.L-1(deficient), 7.5 mmol.L-1 (low) and 15 mmol.L-1 (high). Based on the results, dihydroxyindole, anthranilic acid, N-acetylanthranilic acid significantly discriminated the three treatments. Low nitrogen generally led to the decrease of most amino acids, while the increase of phenylalanine, indole-3-pyruvate acid, and some specialized metabolites including quercetin, indigo and indirubin were observed. The change in content of indole-3-acetic acid (IAA) was speculated to be the potential low nitrogen tolerance mechanism of I. indigotica. Our findings suggest that nitrogen levels significant affect metabolic capacity of Isatis leaf; low nitrogen treatments induce the accumulation of active ingredients. This result will provide leads into understanding the physiological adaption to nitrogen levels of Isatis leaf and quality improvement research of Daqingye.

Isatis indigotica Fortune is a popular herb in traditional Chinese medicine, and various types of metabolites are the basis for its pharmacological efficacy. The biosynthesis and accumulation of these metabolites are closely linked to nitrogen availability; the benefits of low nitrogen application on the environment and herb quality are increasingly prominent. To analyze metabolic changes in the leaves and roots of I.indigotica in nitrogen deficiency conditions, and to identify the pathways and metabolites induced by low nitrogen availability, we used untargeted liquid chromatography coupled with mass spectrometry (UHPLC-TripleTOF) to obtain metabolomics profiling of I.indigotica under two N-deficiency treatments (0 kg/hm(2); 337.5 kg/hm(2)) and normal nitrogen treatment (675 kg/hm(2)). A total of 447 metabolites were annotated. Principal component analysis separated the three nitrogen treatments. A greater diversity of metabolites was observed in roots than in leaves under N-deficiency treatments, suggesting that roots have a more important function in low N tolerance. Differential metabolites were mainly enriched in purine metabolism, phenylpropanoid biosynthesis, the shikimate pathway, tryptophan metabolism, and flavonoid biosynthesis that notably induced only in leaves in low nitrogen stress. Moderate N-deficiency benefits carbohydrate accumulation, whereas accumulation of most amino acids decreases. Uniquely, L-tryptophan was maintained at a high concentration in N-deficiency conditions. Low nitrogen stress induced the accumulation of some specialized metabolites (matairesinol, dictamnine, 5-hydroxyindoleacetate (serotonin) in roots and vitexin, xanthohumol, sinapyl alcohol in leaves). N-deficiency also increased the accumulation of adenosine and quality indicators of I.indigotica (indirubin-indigo, epigoitrin and anthranilic acid) in a certain degree. Our findings showed that nitrogen deficiency modified roots and leaves conditions of I.indigotica, affecting both the primary and secondary metabolism. Moderate nitrogen reduction was beneficial to the accumulation of active ingredients. Our methods and analysis are expected to provide an insight regarding the diversity of metabolites and regulation of their synthesis in low nitrogen application, and better investigate the nitrogen deficiency effect on I.indigotica.

BACKGROUND:Isatis indigotica, a traditional Chinese medicine, produces a variety of active ingredients. However, little is known about the key genes and corresponding expression profiling involved in the biosynthesis pathways of these ingredients. Quantitative real-time polymerase chain reaction (qRT-PCR) is a powerful, commonly-used method for gene expression analysis, but the accuracy of the quantitative data produced depends on the appropriate selection of reference genes.RESULTS:In this study, the systematic analysis of the reference genes was performed for quantitative real-Time PCR normalization in I. indigotica. We selected nine candidate reference genes, including six traditional housekeeping genes (ACT, α-TUB, β-TUB, UBC, CYP, and EF1-α), and three newly stable internal control genes (MUB, TIP41, and RPL) from a transcriptome dataset of I. indigotica, and evaluated their expression stabilities in different tissues (root, stem, leaf, and petiole) and leaves exposed to three abiotic treatments (low-nitrogen, ABA, and MeJA) using geNorm, NormFinder, BestKeeper, and comprehensive RefFind algorithms. The results demonstrated that MUB and EF1-α were the two most stable reference genes for all samples. TIP41 as the optimal reference gene for low-nitrogen stress and MeJA treatment, while ACT had the highest ranking for ABA treatment and CYP was the most suitable for different tissues.CONCLUSIONS:The results revealed that the selection and validation of appropriate reference genes for normalizing data is mandatory to acquire accurate quantification results. The necessity of specific internal control for specific conditions was also emphasized. Furthermore, this work will provide valuable information to enhance further research in gene function and molecular biology on I. indigotica and other related species.

Nitrogen and sulfur are major elements influencing plant growth and production of secondary metabolites. They interact to each other, but little is known about it in Isatis indigotica Fort. plants. In this study, 15 different treatments representing all possible combinations of 3 N treatments (N1, N2, and N3, corresponding to 5, 15, and 25 mM N, respectively) and five S treatments (S0, S1, S2, S3, and S4, corresponding to 0.00, 1.25, 2.50, 5.00 and 7.50 mM S, respectively) were used, and plant growth, indigo and indirubin yields, and expressions of genes encoding enzymes involved in N and S metabolisms were measured. The results show that the highest dry biomass was observed in N2S2 treatment. Moreover, net photosynthetic rate in the N2S2 treatment was significantly higher than under other treatments (except for N3S2 treatment). A low nitrogen concentration (5 mM) was beneficial to the accumulation of alkaloids, and the N1S1 and N2S2 treatments resulted in the highest yields of indigo and indirubin, respectively. Additionally, the yields of indigo and indirubin were positively correlated with the expression of APS reductase and glutamine synthetase genes, respectively.

目的:通过对开花促进因子AGL24基因在菘蓝不同生长时期不同部位的表达量分析,初步探索AGL24在菘蓝花发育进程中的分子调控作用.方法:以安徽亳州菘蓝居群营养生长后期的叶为试验材料提取总RNA,利用RT-PCR技术同源克隆菘蓝AGL24(IiAGL24)基因,并进行生物信息学分析.采用实时荧光定量PCR(qRT-PCR)技术分析AGL24在菘蓝不同时期不同器官中的表达情况.结果:IiAGL24基因完整编码区(CDS区)长648 bp,编码215个氨基酸.进化分析表明IiAGL24基因与十字花科植物萝卜的AGL24序列进化关系最近,同源性高达93.21％.IiAGL24在菘蓝各时期的茎、叶以及初花期的根中表达显著,且随植株进入生殖生长阶段,其表达量增加迅速.但IiAGL24在菘蓝的花、花蕾和果实中表达不显著.结论:AGL24基因在菘蓝的不同时期不同部位表达存在差异性或特异性,其广泛表达于植物的根、茎、叶和花序中,编码典型的MADS域蛋白,具有较高的研究价值.

[目的]探讨减量施氮对菘蓝生长及药材质量的影响,为优化菘蓝栽培中合理施用氮肥提供依据.[方法]以来自于山西(SX)和甘肃(GS)两个产地的菘蓝为材料,进行了田间小区试验.在正常施氮水平N 675 kg/hm2下,设置4个处理CK、1/4N、1/2N、N,施氮量分别为N 0、169、338、675 kg/hm2,探究减量施氮对菘蓝生长指标、营养物质、活性成分含量以及大青叶和板蓝根有效经济产量的影响.[结果]随着施氮水平的提高,山西产地菘蓝鲜重和干重均呈现增加趋势,在正常施氮水平下取得最大值,株鲜重和株干重分别为68.4 g、15.3 g;甘肃产地菘蓝则表现出先增加后略降低的趋势,在1/2N处理下其鲜重和干重值最大,植株鲜重和干重分别为78.5 g、19.7 g.施氮量与菘蓝的根长、株高和主根直径呈正相关,随着施氮量增加,山西、甘肃产地菘蓝的生长指标均显著提高.氮水平对菘蓝的折干率没有显著影响.CK处理下山西与甘肃产地菘蓝的叶内可溶性糖含量、碳氮比均保持在较高水平,游离氨基酸则以N 675 kg/hm2处理最大,二者间没有显著差异.两个产地菘蓝均以CK处理下叶内靛蓝、靛玉红与总黄酮根内的(R,S)-告依春含量最高,且随着施氮水平的提高,呈现出一定的下降趋势,甘肃产地菘蓝对施氮水平变化更为敏感.施氮水平显著影响了大青叶和板蓝根的有效经济产量,在1/4N处理下大青叶有效经济产量更高,且显著高于N处理;山西产地板蓝根的有效经济产量与氮水平呈正相关,在N处理下最大,达到3.31 mg/g,甘肃产地则在1/4N处理下取得最大值2.94 mg/g,综合考虑大青叶和板蓝根,以减量施氮处理下(1/4N、1/2N)菘蓝有效经济产量值更高.[结论]减量施氮对菘蓝生长量和外形品质有不利影响,但有利于其活性成分的积累及有效经济产量的提高,山西和甘肃产地的菘蓝对氮素的响应有所差异.建议栽培生产中可将氮肥施用量控制在169～338 kg/hm2,并根据产地实际情况适当调整.

In this paper, a pot experiment using quartz sands was conducted to study the effects of different concentrations of NaCl (0, 25, 50, 75, 100 mmol·L⁻¹) on the ion absorption, distribution and essential oil components of flowering Schizonepeta tenuifolia. The results showed that as NaCl concentration increased, Na⁺ content of root, stem, leaf and flower increased significantly, and that of the aerial parts was in a higher level than in the root. Regarding the K⁺ content, it decreased in the root but increased in stem, leaf and flower. Some changes were detected in the Ca²⁺ content, but not significant on the whole. The value of K⁺/Na⁺ and Ca²⁺/Na⁺ reduced as a result of increasing NaCl concentrations. The content of essential oil increased under medium salt treatment (50 mmol·L⁻¹ NaCl). However, the synthesis and accumulation of essential oil was inhibited by the serious salt treatment (100 mmol·L⁻¹ NaCl). Over 98% of the essential oil components were terpenes, in which pulegone and menthone were the most two abundant compounds. Varieties of essential oil components did not change significantly under salt stress but their relative proportions did. The transformation of pulegone to menthone was enhanced and the value of pulegone/menthone based on their relative contents decreased with NaCl concentration increasing. Consequently, menthone ranked the most abundant compound by replacing pulegone. Relative content of D-limonene increased under medium and serious salt stress, and that of β-caryophyllene only increased under mild treatments. So our research could provide references for the standard cultivation on saline soil of S. tenuifolia.