Opisthopappus Taihangensis Research Articles

Integrated omics profiles for exploring the potential mechanism underlying aroma formation in the terpenoid-rich aromatic plant Opisthopappus taihangensis and the bioactivity of its leaf essential oil

Integrated omics profiles for exploring the potential mechanism underlying aroma formation in the terpenoid-rich aromatic plant Opisthopappus taihangensis and the bioactivity of its leaf essential oil

Genome-wide identification, characterization and expression of C2H2 zinc finger gene family in Opisthopappus species under salt stress

BackgroundThe C2H2 zinc finger protein family plays important roles in plants. However, precisely how C2H2s function in Opisthopappus (Opisthopappus taihangensis and Opisthopappus longilobus) remains unclear.ResultsIn this study, a total of 69 OpC2H2 zinc finger protein genes were identified and clustered into five Groups. Seven tandem and ten fragment repeats were found in OpC2H2s, which underwent robust purifying selection. Of the identified motifs, motif 1 was present in all OpC2H2s and conserved at important binding sites. Most OpC2H2s possessed few introns and exons that could rapidly activate and react when faced with stress. The OpC2H2 promoter sequences mainly contained diverse regulatory elements, such as ARE, ABRE, and LTR. Under salt stress, two up-regulated OpC2H2s (OpC2H2-1 and OpC2H2-14) genes and one down-regulated OpC2H2 gene (OpC2H2-7) might serve as key transcription factors through the ABA and JA signaling pathways to regulate the growth and development of Opisthopappus species.ConclusionThe above results not only help to understand the function of C2H2 gene family but also drive progress in genetic improvement for the salt tolerance of Opisthopappus species.

The Genome-Wide Identification, Characterization, and Expression Profiles of the NADPH Oxidase (NOX) Gene Family under Drought and Salt Stress in Opisthopappus taihangensis (Asteraceae)

Plant NAPDH oxidase (NOX) gene family members are critical producers of ROS and play crucial roles in plant signaling, development, and stress responses. Opisthopappus taihangensis is a pivotal wild genetic resource in Asteraceae. To date, little knowledge exists about the functions of NOXs in O. taihangensis. In this study, seven typical NOXs and seven ferric reduction oxidases (FROs) were identified in O. taihangensis. Dispersed duplication might play a critical role in the expansion of the NOX/FRO gene family in O. taihangensis, and most of the NOX/FRO homologous pairs have undergone purifying selection. Although the results of the collinearity analysis show that these genes were relatively conserved, the gain and loss of members in this gene family occurred frequently during the evolution of Asteraceae. Phylogenetic analysis indicated that the FROs are relatively ancient, and the earliest diverged branch was revealed by the maximum likelihood (ML) tree. The Asteraceae NOXs were divided into six subgroups according to their relationship with Arabidopsis and rice members. The transcriptome profile unveiled tissue-specific expression patterns and complex response modes under drought and salt stresses. OtNOX6 and OtNOX7 could be recognized as important candidates to respond to drought and salt stress. Our results provide clues and references for further in-depth exploration of NOX/FRO function in O. taihangensis and other horticulture plants.

Potential Response Patterns of Endogenous Hormones in Cliff Species Opisthopappus taihangensis and Opisthopappus longilobus under Salt Stress.

When plants are exposed to salt stress, endogenous hormones are essential for their responses through biosynthesis and signal transduction pathways. However, the roles of endogenous hormones in two cliff species (Opisthopappus taihangensis and Opisthopappus longilobus (Opisthopappus genus)) in the Taihang Mountains under salt stress have not been investigated to date. Following different time treatments under 500 mM salt concentrations, 239 differentially expressed gene (DEG)-related endogenous hormones were identified that exhibited four change trends, which in Profile 47 were upregulated in both species. The C-DEG genes of AUX, GA, JA, BR, ETH, and ABA endogenous hormones were significantly enriched in Opisthopappus taihangensis (O. taihangensis) and Opisthopappus longilobus (O. longilobus). During the responsive process, mainly AUX, GA, and JA biosynthesis and signal transduction were triggered in the two species. Subsequently, crosstalk further influenced BR, EHT, ABA, and MAPK signal transduction pathways to improve the salt resistance of the two species. Within the protein-protein interactions (PPI), seven proteins exhibited the highest interactions, which primarily involved two downregulated genes (SAUR and GA3ox) and eight upregulated genes (ACX, MFP2, JAZ, BRI1, BAK1, ETR, EIN2, and SNRK2) of the above pathways. The more upregulated expression of ZEP (in the ABA biosynthesis pathway), DELLA (in the GA signaling pathway), ABF (in the ABA signaling pathway), and ERF1 (in the ETH signaling pathway) in O. taihangensis revealed that it had a relatively higher salt resistance than O. longilobus. This revealed that the responsive patterns to salt stress between the two species had both similarities and differences. The results of this investigation shed light on the potential adaptive mechanisms of O. taihangensis and O. longilobus under cliff environments, while laying a foundation for the study of other cliff species in the Taihang Mountains.

Responsive Alternative Splicing Events of Opisthopappus Species against Salt Stress.

Salt stress profoundly affects plant growth, prompting intricate molecular responses, such as alternative splicing (AS), for environmental adaptation. However, the response of AS events to salt stress in Opisthopappus (Opisthopappus taihangensis and Opisthopappus longilobus) remains unclear, which is a Taihang Mountain cliff-dwelling species. Using RNA-seq data, differentially expressed genes (DEGs) were identified under time and concentration gradients of salt stress. Two types of AS, skipped exon (SE) and mutually exclusive exons (MXE), were found. Differentially alternative splicing (DAS) genes in both species were significantly enriched in "protein phosphorylation", "starch and sucrose metabolism", and "plant hormone signal transduction" pathways. Meanwhile, distinct GO terms and KEGG pathways of DAS occurred between two species. Only a small subset of DAS genes overlapped with DEGs under salt stress. Although both species likely adopted protein phosphorylation to enhance salt stress tolerance, they exhibited distinct responses. The results indicated that the salt stress mechanisms of both Opisthopappus species exhibited similarities and differences in response to salt stress, which suggested that adaptive divergence might have occurred between them. This study initially provides a comprehensive description of salt responsive AS events in Opisthopappus and conveys some insights into the molecular mechanisms behind species tolerance on the Taihang Mountains.

Responses of Aroma Related Metabolic Attributes of Opisthopappus longilobus Flowers to Environmental Changes.

Opisthopappus longilobus (Opisthopappus) and its descendant species, Opisthopappus taihangensis, commonly thrive on the Taihang Mountains of China. Being typical cliff plants, both O. longilobus and O. taihangensis release unique aromatics. To determine the potential differentiation and environmental response patterns, comparative metabolic analysis was performed on O. longilobus wild flower (CLW), O. longilobus transplant flower (CLT), and O. taihangensis wild flower (TH) groups. Significant differences in the metabolic profiles were found, not within O. longilobus, but between O. longilobus and O. taihangensis flowers. Within these metabolites, twenty-eight substances related to the scents were obtained (one alkene, two aldehydes, three esters, eight phenols, three acids, three ketones, three alcohols, and five flavonoids), of which eugenol and chlorogenic were the primary aromatic molecules and enriched in the phenylpropane pathway. Network analysis showed that close relationships occurred among identified aromatic substances. The variation coefficient (CV) of aromatic metabolites in O. longilobus was lower than O. taihangensis. The aromatic related compounds were significantly correlated with the lowest temperatures in October and in December of the sampled sites. The results indicated that phenylpropane, particularly eugenol and chlorogenic, played important roles in the responses of O. longilobus species to environmental changes.

Complete Chloroplast Genome Sequence of Endangered Species in the Genus Opisthopappus C. Shih: Characterization, Species Identification, and Phylogenetic Relationships.

Opisthopappus C. Shih is a rare genus of the Asteraceae family native to the Taihang Mountains in China. Due to the narrow distribution area, poor reproduction ability and human harvesting, Opisthopappus is threatened by extinction. However, the limited genetic information within Opisthopappus impede understanding of the conservation efforts and bioprospecting. Therefore, in this study, we reported the complete chloroplast (cp) genome sequences of two Opisthopappus species, including Opisthopappus taihangensis and Opisthopappus longilobus. The cp genomes of O. taihangensis and O. longilobus were 151,117 and 151,123 bp, which contained 88 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The repeat sequences, codon usage, RNA-editing sites, and comparative analyses revealed a high degree of conservation between the two species. The ycf1 gene was identified as a potential molecular marker. The phylogenetic tree demonstrated that O. longilobus was a separate species and not a synonym or variety of O. taihangensis. The molecular clock showed that two species diverge over a large time span, O. longilobus diverged at 15.24 Mya (Million years ago), whereas O. taihangensis diverged at 5.40 Mya We found that Opisthopappus and Ajania are closely related, which provides new ideas for the development of Opisthopappus. These results provide biological information and an essential basis to understand the evolutionary history of the Opisthopappus species, which will aid in the future the bioprospecting and conservation of endangered species.

Terpenoids and their gene regulatory networks in Opisthopappus taihangensis 'Taihang Mingzhu' as detected by transcriptome and metabolome analyses.

‘Taihang Mingzhu’ is the hybrid offspring of Opisthopappus taihangensis, and it has an excellent characteristic of whole-plant fragrance. At present, the genes and metabolites involved in the synthesis of its aromatic compounds are unknown because of the paucity of molecular biology studies on flowering in the Opisthopappus Shih genus. To elucidate the biosynthetic pathways of terpenoids, the main aromatic compounds in ‘Taihang Mingzhu’, we conducted transcriptome and metabolite analyses on its leaves and bud, inflorescences at the color-development, flowering, and full-bloom stages. A total of 82,685 unigenes were obtained, of which 43,901 were annotated on the basis of information at the protein databases Nr, SwissProt, KEGG, and COG/KOG (e-value<0.00001). Using gas headspace solid-phase microextraction chromatography – mass spectrometry (HS-SPME-GC/MS), 1350 metabolites were identified, the most abundant of which were terpenoids (302 metabolites). Analyses of the gene regulatory network of terpenoids in ‘Taihang Mingzhu’ identified 52 genes potentially involved in the regulation of terpenoid synthesis. The correlations between genes related to terpenoid metabolism/regulation and metabolite abundance were analyzed. We also extracted the essential oil from the leaves of ‘Taihang Mingzhu’ by hydrodistillation, and obtained 270 aromatic compounds. Again, the most abundant class was terpenoids. These results provide guidance for the extraction of essential oil from ‘Taihang Mingzhu’ leaves and flowers. In addition, our analyses provide valuable genetic resources to identify genetic targets to manipulate the aromatic profiles of this plant and other members the Opisthopappus Shih genus by molecular breeding.

Adaptation insights from comparative transcriptome analysis of two Opisthopappus species in the Taihang mountains

Opisthopappus is a major wild source of Asteraceae with resistance to cold and drought. Two species of this genus (Opisthopappus taihangensis and O. longilobus) have been employed as model systems to address the evolutionary history of perennial herb biomes in the Taihang Mountains of China. However, further studies on the adaptive divergence processes of these two species are currently impeded by the lack of genomic resources. To elucidate the molecular mechanisms involved, a comparative analysis of these two species was conducted. Among the identified transcription factors, the bHLH members were most prevalent, which exhibited significantly different expression levels in the terpenoid metabolic pathway. O. longilobus showed higher level of expression than did O. taihangensis in terms of terpenes biosynthesis and metabolism, particularly monoterpenoids and diterpenoids. Analyses of the positive selection genes (PSGs) identified from O. taihangensis and O. longilobus revealed that 1203 genes were related to adaptative divergence, which were under rapid evolution and/or have signs of positive selection. Differential expressions of PSG occurred primarily in the mitochondrial electron transport, starch degradation, secondary metabolism, as well as nucleotide synthesis and S-metabolism pathway processes. Several PSGs were obviously differentially expressed in terpenes biosynthesis that might result in the fragrances divergence between O. longilobus and O. taihangensis, which would provide insights into adaptation of the two species to different environments that characterized by sub-humid warm temperate and temperate continental monsoon climates. The comparative analysis for these two species in Opisthopappus not only revealed how the divergence occurred from molecular perspective, but also provided novel insights into how differential adaptations occurred in Taihang Mountains.

Detection and analysis of the volatile components in the essential oils of &lt;i&gt;Chrysanthemum&lt;/i&gt; and &lt;i&gt;Opisthopappus&lt;/i&gt; species and their hybrid progeny

<italic>Chrysanthemum</italic> and <italic>Opisthopappus</italic> are genera that include perennial herbaceous floral species, including excellent varieties with strong fragrances resulting from long-term artificial selection. Thus, they are ornamentally and economically important flower resources. In this study, a water distillation method was used to extract essential oils from the inflorescences of <italic>Chrysanthemum</italic> and <italic>Opisthopappus</italic> wild resources and hybrid progeny with high essential oil contents (<italic>Chrysanthemum</italic> <italic>morifolium</italic> 'xiangjin', <italic>C. morifolium</italic> 'xiangyun', <italic>C. morifolium</italic> 'xinjiboju', <italic>Opisthopappus taihangensis</italic>, <italic>Opisthopappus longilobus</italic>, <italic>Chrysanthemum lavandulifolium</italic>, and <italic>C. morifolium</italic> 'minghuangju'). The essential oil extraction rates were as follows: 1.17‰, 2‰, 1.67‰, 2.17‰, 0.43‰, 1‰, and 1.17‰. On the basis of HS-SPME-GC-MS (Headspace solid phase microextraction-gas chromatography-mass spectrometry), 225 volatile compounds were detected in the seven analyzed essential oil samples. Each essential oil had a relative volatile component content exceeding 0.3. The three most abundant compounds were olefins (46 types), alcohols (34 types), and esters (18 types). The volatile components with relatively high contents included thymol, D-camphor, pinene, eucalyptol, 2-terpineol, terpineol, trans-caryophyllene, and <italic>β</italic>-elemene. These volatile compounds have strong biological activities and are useful components of medicines and daily-use products. An evaluation of their antibacterial effects demonstrated that the essential oils of <italic>C.</italic> 'xiangjin', <italic>C.</italic> 'xiangyun', <italic>C.</italic> 'xinjiboju', <italic>O. taihangensis</italic>, <italic>O. longilobus</italic>, and <italic>C.</italic> 'minghuangju' inhibited the growth of <italic>Escherichia coli</italic>. The <italic>C. lavandulifolium</italic> essential oil inhibited the growth of <italic>Pectobacterium carotovorum</italic>. The results of this study will provide researchers with an important theoretical basis for the development and application of <italic>Chrysanthemum</italic> and <italic>Opisthopappus</italic> essential oils.

Identification of the Volatile Compounds and Observation of the Glandular Trichomes in Opisthopappus taihangensis and Four Species of Chrysanthemum.

Opisthopappus taihangensis (Ling) Shih, a wild relative germplasm of chrysanthemum, releases a completely different fragrance from chrysanthemum species. We aimed to identify the volatile compounds of the leaves of O. taihangensis and four other Chrysanthemum species using headspace solid-phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC/MS). In total, 70 compounds were detected, and terpenoids accounted for the largest percentage in these five species. Many specific compounds were only emitted from O. taihangensis and not from the other four species. In particular, 1,8-cineole could be responsible for the special leaf fragrance of O. taihangensis as it accounted for the largest proportion of the compounds in O. taihangensis but a small or no proportion at all in other species. The glandular trichomes (GTs) in the leaves are the main organs responsible for the emission of volatiles. To explore the relationship between the emissions and the density of the GTs on the leaf epidermis, the shape and density of the GTs were observed and calculated, respectively. The results showed that the trichomes have two shapes in these leaves: T-shaped non-glandular trichomes and capitate trichomes. Histochemical staining analyses indicated that terpenoids are mainly emitted from capitate glandular trichomes. Correlation analysis showed that the volatile amount of terpenoids is highly related to the density of capitate trichomes. In O. taihangensis, the terpenoids content and density of capitate trichomes are the highest. We identified the diversity of leaf volatiles from O. taihangensis and four other Chrysanthemum species and found a possible relationship between the content of volatile compounds and the density of capitate trichomes, which explained the cause of the fragrance of O. taihangensis leaves.

Genetic Divergence and Relationship Among Opisthopappus Species Identified by Development of EST-SSR Markers.

Opisthopappus Shih is an endemic and endangered genus restricted to the Taihang Mountains that has important ornamental and economic value. According to the Flora Reipublicae Popularis Sinicae (FRPS, Chinese version), this genus contains two species (Opisthopappus longilobus and Opisthopappus taihangensis), whereas in the Flora of China (English version) only one species O. taihangensis is present. The interspecific phylogenetic relationship remains unclear and undefined, which might primarily be due to the lack of specific molecular markers for phylogenetic analysis. For this study, 2644 expressed sequence tag-simple sequence repeats (EST-SSRs) from 33,974 unigenes using a de novo transcript assembly of Opisthopappus were identified with a distribution frequency of 7.78% total unigenes. Thereinto, mononucleotides (1200, 45.39%) were the dominant repeat motif, followed by trinucleotides (992, 37.52%), and dinucleotides (410, 15.51%). The most dominant trinucleotide repeat motif was ACC/GGT (207, 20.87%). Based on the identified EST-SSRs, 245 among 1444 designed EST-SSR primers were selected for the development of potential molecular markers. Among these markers, 63 pairs of primers (25.71%) generated clear and reproducible bands with expected sizes. Eventually, 11 primer pairs successfully amplified all individuals from the studied populations. Through the EST-SSR markers, a high level of genetic diversity was detected between Opisthopappus populations. A significant genetic differentiation between the O. longilobus and O. taihangensis populations was found. All studied populations were divided into two clusters by UPGMA, NJ, STRUCTURE, and PCoA. These results fully supported the view of the FRPS, namely, that O. longilobus and O. taihangensis should be regarded as two distinct species. Our study demonstrated that transcriptome sequences, as a valuable tool for the quick and cost-effective development of molecular markers, was helpful toward obtaining comprehensive EST-SSR markers that could contribute to an in-depth assessment of the genetic and phylogenetic relationships between Opisthopappus species.

Root Physiological Traits and Transcriptome Analyses Reveal that Root Zone Water Retention Confers Drought Tolerance to Opisthopappus taihangensis

Opisthopappus taihangensis (Ling) Shih, as a relative of chrysanthemum, mainly survives on the cracks of steep slopes and cliffs. Due to the harsh environment in which O. taihangensis lives, it has evolved strong adaptive traits to drought stress. The root system first perceives soil water deficiency, triggering a multi-pronged response mechanism to maintain water potential; however, the drought tolerance mechanism of O. taihangensis roots remains unclear. Therefore, roots were selected as materials to explore the physiological and molecular responsive mechanisms. We found that the roots had a stronger water retention capacity than the leaves. This result was attributed to ABA accumulation, which promoted an increased accumulation of proline and trehalose to maintain cell osmotic pressure, activated SOD and POD to scavenge ROS to protect root cell membrane structure and induced suberin depositions to minimize water backflow to dry soil. Transcriptome sequencing analyses further confirmed that O. taihangensis strongly activated genes involved in the ABA signalling pathway, osmolyte metabolism, antioxidant enzyme activity and biosynthesis of suberin monomer. Overall, these results not only will provide new insights into the drought response mechanisms of O. taihangensis but also will be helpful for future drought breeding programmes of chrysanthemum.

Physiological and transcriptome analyses of Opisthopappus taihangensis in response to drought stress

BackgroundWater scarcity is considered to be a severe environmental constraint to plant survival and productivity. Studies on drought-tolerant plants would definitely promote a better understanding of the regulatory mechanism lying behind the adaptive response of plants to drought. Opisthopappus taihangensis (ling) shih is a typical drought-tolerant perennial plant species endemically distributed across the Taihang Mountains in China, but the underlying mechanism for drought tolerance of this particular species remains elusive.ResultsTo mimic natural drought stress, O. taihangensis plants were treated with two different concentrations (25% and 5%) of polyethylene glycol (PEG6000), which represent the H group (high salinity) and the L group (low salinity), respectively. The physiological characteristics of these two groups of plants, including relative water content maintenance (RWC), proline content and chlorophyll content were assessed and compared with plants in the control group (CK), which had normal irrigation. There was not a significant difference in RWC when comparing plants in the L group with the control group. Proline was accumulated to a higher level, and chlorophyll content was decreased slightly in plants under low drought stress. In plants from the H group, a lower RWC was observed. Proline was accumulated to an even higher level when compared with plants from the L group, and chlorophyll content was further reduced in plants under high drought stress. Transcriptomic analysis was carried out to look for genes that are differentially expressed (DEGs) in O. taihangensis plants coping adaptively with the two levels of drought stress. A total of 23,056 genes are differentially expressed between CK and L, among which 12,180 genes are up-regulated and 10,876 genes are down-regulated. Between H and L, 6182 genes are up-regulated and 1850 genes are down-regulated, which gives a total of 8032 genes. The highest number of genes, that are differentially expressed, was obtained when a comparison was made between CK and H. A total of 43,074 genes were found to be differentially expressed with 26,977 genes up-regulated and 16,097 genes down-regulated. Further analysis of these genes suggests that many of the up-regulated genes are enriched in pathways involved in amino acid metabolism. Besides, 39 transcription factors (TFs) were found to be continuously up-regulated with the increase of drought stress level.ConclusionTaken together, the results indicate that O. taihangensis plants are able to live adaptively under drought stress by responding physiologically and regulating the expression of a substantial number of drought-responsive genes and TFs to avoid adverse effects.

The complete chloroplast genome of Opisthopappus taihangensis (Ling) Shih

Opisthopappus taihangensis (Ling) Shih is a monotypic species (Anthemideae, Asteraceae) and an endemic endangered plant of China. In this study, we sequenced the complete chloroplast genome of O. taihangensis using Illumina HiSeq X Ten platform. The total length of O. taihangensis chloroplast genome is 151,089 bp, including a large single-copy region of length 82,877 bp, a small single-copy region of length 18304 bp, and a pair of 24,954-bp inverted repeat regions. The chloroplast genome of O. taihangensis has 132 genes, including 87 protein-coding, eight ribosomal RNA, and 37 transfer RNA genes. The overall GC content of the whole genome was 37.5%. The phylogenetic analysis revealed a close relationship between O. taihangensis and Chrysanthemum boreale.

De novo Assembly and Transcriptome Characterization of Opisthopappus (Asteraceae) for Population Differentiation and Adaption.

Opisthopappus Shih (Asteraceae), an endangered genus endemic to the Taihang Mountains of China, is a high-value ornamental and medicinal plant consisting of two species, Opisthopappus longilobus shih and Opisthopappus taihangensis (Ling) Shih. However, the evolutionary relationships and the taxonomic characteristics between the two species remain unknown. In this study, high-throughput transcriptome sequencing was used to analyze the differential metabolic activity and gene expression and screened special molecular markers for exploring the genetic variation and species differentiation in Opisthopappus Shih. The results showed that 33,974 unigenes with an average size of 801 bp were obtained with optimization of de novo assembly. The comprehensive functional annotation based on Gene Ontology (GO), Cluster of Orthologous Group (COG) and Kyoto Encyclopedia of Genes and Genomes pathway database (KEGG) revealed that these unigenes were mainly related to many physiological, metabolic, and molecular processes. Furthermore, the comparative transcriptome analysis indicated that 3,410 differentially expressed genes were mainly involved in lipid, carbohydrate and amino acid metabolism, xenobiotics biodegradation and metabolism as well as environment adaptation via KEGG. Such as the CYP710A, GST, HSP90A and so on, could be the potential candidate genes for further investigating the molecular mechanism of physiological variations between O. taihangensis and O. longilobus. In addition, the potential 71,804 high quality single nucleotide polymorphisms (SNPs) and 1,444 simple sequence repeats (SSRs) were estimated. Based on the predicted SNP, we have developed eight SNP markers for population genetic analysis in Opisthopappus Shih. A significantly high level of genetic differentiation between the populations of O. longilobus and O. taihangensis were found, and they were clearly grouped into two distinct genetic clusters. These results conformed to the record of Flora Reipublicae Popularis Sinicae (FRPS) and unsupported the taxonomic status in the Flora of China. The transcriptome analysis of Opisthopappus Shih can contribute to in-depth exploring of internal mechanisms in species variation and differentiation based on molecular evidence. With the rich and valuable data resources, the more novel structural, functional, and comparative genomic studies will provide comprehensive insights into the evolutionary relationships between O. taihangensis and O. longilobus.

Optimization of SRAP-PCR System for Opisthopappus taihangensis(Ling) Shih by Uniform Design

In the present study,SRAP-PCR reaction conditions for Opisthopappus taihangensis( Ling) Shih were optimized. The factors affecting SRAP results of O. taihangensis were investigated by uniform designs of two times. The optimal protocol was accomplished in 10 μL reaction volumes containing 1. 3 μL template DNA,0. 35 μL primers and 5. 3 μL 2 × Taq MasterMix. Under this optimal condition,clear and polymorphic bands from 11 O. taihangensis plants had been obtained using Me1 /em4 primers. The result showed that the reaction condition was suitable for SRAP-PCR reaction system of O. taihangensis.

Leaves Micromorphological Characteristics ofOpisthopappustaihangensisandOpisthopappus longilobusfromTaihang Mountain, China

Leaves Micromorphological Characteristics of Opisthopappus taihangensis and Opisthopappus longilobus from Taihang Mountain, China The micromorphological characteristics of Opisthopappus taihangensis and Opisthopappus longilobus leaves were observed using scanning electron microscope and was found that they differ in characteristics and density of glandular hairs, size and density of stomata, pattern of anticlinal wall, wax characteristics, size and density of salt vesicles. These differences mainly resulted from the microenvironment heterogeneity of these two species or different populations. The micromorphological characteristics of the leaves, stomata and salt vesicles could be regarded as important classification traits for O. taihangensis and O. longilobus. Correlation analysis indicated that there was a significant relationship between morphological characteristics, longitude and latitude. According to principal component analysis, the highest contribution came from the density of glandular hairs. All the 13 populations of Opisthopappus were gathered into two clusters based on the microstructural characteristics of their leaves. Three populations of O. longilobus were not gathered into a single cluster, but with different populations of O. taihangensis.

Development and characterization of microsatellite loci in Opisthopappus taihangensis (Compositae), a rare herb endemic to China

Using an enriched genomic library, we developed and characterized 10 polymorphic microsatellite primers for Opisthopappus taihangensis, a rare herb endemic to China. Number of alleles varied from 2 to 8 per locus, observed and expected heterozygosities ranged from 0.214 to 0.929 and 0.262 to 0.746 respectively. Significantly deviations from HWE were detected in two loci. These microsatellite loci would be useful for studies of genetic variation, genetic structure, and mating systems of O. taihangensis, which are important for the further conservation of this rare species.

Genetic diversity and population structure of Opisthopappus longilobus and Opisthopappus taihangensis (Asteraceae) in China determined using sequence related amplified polymorphism markers

Abstract The genetic diversity and structure of four Opisthopappus longilobus and nine Opisthopappus taihangensis populations from Mts. Taihang were analyzed using SRAP markers. The results showed that O. longilobus ( PPB = 95.16%, H = 0.349, I = 0.517) and O. taihangensis populations ( PPB = 94.58%, H = 0.332, I = 0.504) had high genetic diversity. The genetic diversity within populations varied according to two species. Low genetic differentiation was detected among O. longilobus ( Φ ST = 0.105) and O. taihangensis ( Φ ST = 0.188) populations, respectively. Significantly genetic variation was found between O. longilobus and O. taihangensis ( Φ ST = 0.232). The dendrogram generated from pairwise genetic distance among all populations showed two distinct clusters, each corresponding to one species. A Mantel test revealed insignificant positive correlation between genetic distances and geographic distances ( r O . longilobus = 0.3021; r O. taihangensis = 0.3658; P > 0.05). Those results indicated that self-compatibility, effective gene flow, biological traits, and historical factors may be the main factors causing geographical differentiation in the structure of O. longilobus and O. taihangensis populations.