Search Results (159)

Fritillaria unibracteata is a rare and endangered medicinal plant in the Liliaceae family, whose bulbs have been used in traditional Chinese traditional medicine for over 2000 years. The mevalonate (MVA) pathway is involved in the growth, development, response to environmental stress, and active ingredient production of plants; however, the functional characterization of MVA-pathway genes in the Liliaceae family remains poorly documented. In this study, an Acetyl-CoA C-acetyltransferase gene (FuAACT) was first cloned from F. unibracteata. It exhibited structural features of the thiolase family and showed the highest sequence identity with the Dioscorea cayenensis homolog. The K_m, V_max, and K_cat of the recombinant FuAACT were determined to be 3.035 ± 0.215 μM, 0.128 ± 0.0058 μmol/(min·mg), and 1.275 ± 0.0575 min⁻¹, respectively. The optimal catalytic conditions for FuAACT were ascertained to be 30 °C and pH 8.9. It was stable below 50 °C. His361 was confirmed to be a key amino acid residue to enzymatic catalysis by site-directed mutagenesis. Subsequent subcellular localization experiments demonstrated that FuAACT was localized in chloroplasts and cytoplasm. FuAACT-overexpressing transgenic Arabidopsis thaliana plants showed higher drought tolerance than wild-type plants. This phenotypic difference was corroborated by significant differences in seed germination rate, lateral root number, plant height, and leaf number (p < 0.05). Furthermore, the FuAACT transgenic plants resulted in the formation of a more developed fibrous root system. These results indicated that the FuAACT gene revealed substantial biological activity in vitro and in vivo, hopefully providing the basis for its further research and application in liliaceous ornamental and medicinal plants. Full article

Accurate taxonomy is fundamental for assessing extinction risks and implementing conservation strategies. We evaluated the extinction risk of Grindelia atlantica (Asteraceae), endemic to southern Brazil, using the IUCN criteria, and comparing three scenarios of taxonomic accuracy and data availability. Herbaria records and field surveys confirmed the historical existence of five records and currently only two remaining, isolated populations, totaling 633 individuals (513 in Pelotas and Rio Grande; 120 in Jaguarão). Habitat loss and invasive species are the primary threats. Analyses resulted in an Extent of Occurrence of 475.832 km² and an Area of Occupancy of 36 km². These findings, coupled with significant population decline, justify the classification as Critically Endangered. The results emphasize the critical role of reliable taxonomy in conservation biology. They demonstrate the impact of a few errors on extinction risk assessments, which can unfold in the misallocation of resources or insufficient protection. This is critical, particularly for endemic species like G. atlantica in the threatened Pampas, one of Brazil’s most degraded biomes and the least represented in preserves. The creation of a conservation unit is proposed as an urgent measure to ensure the survival of this species and its habitat, benefiting other endemic and rare threatened animal and plant species. Full article

Platycrater arguta (Hydrangeaceae), a rare and endangered Tertiary relict shrub endemic to East Asia, holds significant ecological and evolutionary value. However, the P. arguta mitochondrial (mt) genome remains unexplored, limiting insights into its cytoplasmic evolution and phylogenetic relationships. In this study, a complete mt genome of P. arguta was sequenced, and we assembled the mt genome into two linear contigs for description, due to the complexity of its chromosome structure. The mt genome encodes 37 protein-coding genes, 27 tRNA genes, and three rRNA genes. A total of 687 RNA editing sites were predicted, and the most RNA editing sites were found in the nad4 gene. Repeat sequences with different sizes were detected in the mt genome, including 160 simple sequence repeats, 26 tandem repeats, and 320 dispersed repeats. Phylogenetic analysis grouped P. arguta with Hydrangea macrophylla (Hydrangeaceae), which is closely related to Eucommiaceae and Ericaceae. This study provides the first assembled and annotated mt genome of P. arguta, which enhances our understanding of the genome of this relict plant in Hydrangeaceae. Taken together, this study offered foundational data for conservation strategies, molecular breeding, and evolutionary studies of this endangered relict species. Full article

Nymphaea candida Presl is a rare hardy water lily at risk of extinction and has been included on the ‘Red List’ of threatened species of the International Union for the Conservation of Nature. To protect germplasm resources and propagate N. candida seedlings, this study conducted tissue culture and found that pathogenic endophytic fungal infection was the main reason for failure of tissue culture. Compared with the stems and leaves, the roots of N. candida had the highest rates of fungal infection during tissue culture. Subsequently, three isolated endophytic fungi, Fusarium oxysporum, Phytopythium helicoides, and Alternaria sp., showed the highest frequency of occurrence in tissue culture. Furthermore, an antifungal formulation comprising 0.1 μg/mL pyrimidin suspension, 1 μg/mL mancozeb wettable powder, and 1 μg/mL carbendazim was constructed and could reduce the infection rates of root and stem tissues to 7.5% and 0%, respectively. Finally, the usefulness of this antifungal formulation for inhibition of endophytic fungi in tissue culture of N. candida was validated. This study not only provides important technical support for mass production of seedlings of N. candida, but also provides a scientific reference for the protection of endangered aquatic plant species. Full article

A study was conducted on the vascular floras of the Ziwuling Mountains in Shaanxi Province to establish a foundational database, providing data support for the conservation and utilization of the Ziwuling Mountains’ plant diversity resources. Based on field surveys and literature references, the composition and geographical elements of the vascular floras in the study area were analyzed. The species richness and floristic similarity coefficients of the study area were compared with other floras on the Ordos Platform. The results were as follows: (1) The vascular floras of the Ziwuling Mountains in Shaanxi Province comprised 120 families, 498 genera, and 965 species, with superrosids and superasterids being significantly dominant. There were 15 dominant families, primarily composed of oligotypic and monotypic genera. In terms of life forms, perennial forbs were the most abundant. (2) At the family level, tropical elements slightly outweighed temperate elements; at the genus level, temperate elements dominated. (3) The study area was rich in rare and endangered species. (4) Compared with other floras on the Ordos Platform, the study area exhibited higher species richness and the greatest similarity with the Liupan Mountain floras. The biodiversity of the Ziwuling Mountains in Shaanxi Province was relatively high, with diverse geographical elements and abundant rare and endangered species resources. Full article

Glochidion chodoense, a rare and endangered plant endemic to Republic of Korea, is known for containing a wide variety of phytochemicals, including triterpenoid saponins and flavonoids. This study sought to profile the phytochemical composition of the leaves and branches of G. chodoense harvested during three different periods (May, July, and October 2023) using liquid chromatography–electrospray ionization/mass spectrometry (LC-ESI/MS) and high-performance liquid chromatography–photodiode array detection (HPLC/PDA). Plant materials were harvested, authenticated, and subjected to ethanol extraction prior to chemical analysis. LC-ESI/MS and quantitative HPLC/PDA analyses were conducted to identify and quantify nine key phytochemicals: norbergenin (1), bergenin (2), epigallocatechin (3), ethyl gallate (4), orientin (5), epicatechin gallate (6), isovitexin 2″-O-arabinoside (7), ellagic acid (8), and cynaroside (9). Our findings revealed significant seasonal variations in major phytochemicals, with leaves containing higher concentrations than branches. Notably, bergenin (2) showed the highest content in May leaves (43.42 mg/g extract), followed by October (17.60 mg/g extract) and July branches (8.56 mg/g extract). Ethyl gallate (4), which was absent or present in trace amounts in branches, was abundant in leaves, with concentrations of 22.24 mg/g extract in October, 21.75 mg/g extract in May, and 17.48 mg/g extract in July. A similar trend was observed for norbergenin (1). These findings provide valuable insights into the phytochemical composition of G. chodoense, emphasizing its potential applications in pharmaceuticals, cosmetics, and functional foods, while highlighting the critical importance of conserving this endangered species. Full article

Puya raimondii Harms is a charismatic species discovered in the Cordillera Blanca (now Huascarán National Park, Peru) in 1867 by the great Italian-born Peruvian geographer and naturalist Antonio Raimondi. The importance of this plant is due to its imposing size, the rare and extreme ecosystem that depends on it, and the fact that it is linked to the name Antonio Raimondi. Four studies on its genetic diversity revealed a range of patterns, with a fixation index of 0.740 as weighted mean and gene flow as low as 0.02–0.03. In fact, the vast majority of the total genetic variation was documented between populations, with very low genetic variation found within populations (weighted mean genetic diversity as low as Hs = 0.072 and mean genetic similarity very high, ranging from 96% up to 99%). We hypothesize that the narrow genetic base of P. raimondii populations may be due to a combination of factors: (i) an inbreeding-based reproductive strategy (i.e., mating between individuals related by common ancestry), which leads to homozygosity and genomic uniformity; (ii) strong environmental selective pressure (e.g., day–night temperature excursion, long dry period, etc.), which favors only the highest fitness individual genotypes; and (iii) a long life cycle, which hampers recombination events and reduces genetic diversity. Overall, these factors suggest that P. raimondii is a genetically fragile, fragmented, and endangered species. Full article

Glyptostrobus pensilis is an endangered tree species, and detecting its genetic diversity can reveal the mechanisms of endangerment, providing references for the conservation of genetic resources. Samples of 137 trees across seven populations within Fujian Province were collected and sequenced using double-digest restriction site-associated DNA (ddRAD-seq). A total of 3,687,189 single-nucleotide polymorphisms (SNPs) were identified, and 15,158 high-quality SNPs were obtained after filtering. The genetic diversity in the populations was found to be low (H_o = 0.08630, H_e = 0.03475, π = 0.07239), with a high genetic differentiation coefficient (F_st). When K = 4, the coefficient of variation (CV) error value was minimized, suggesting that the 137 individuals could be divided into four groups, with frequent gene flow between them. Principal component analysis (PCA) divided the seven populations into two major categories based on their north–south geographic location. The clustering was consistent with those obtained from the PCA. The main reasons for the endangerment of G. pensilis are likely to be poor natural regeneration, human disturbances, and climatic factors. It is recommended that methods such as in situ conservation, ex situ conservation, and the establishment of germplasm banks be implemented to maintain the genetic diversity of G. pensilis populations. Full article

Viola ucriana Erben & Raimondo is a rare and endangered taxon, endemic to a limited area on Mount Pizzuta in northwestern Sicily, Italy. Its population is significantly threatened by anthropogenic activities, including fires, overgrazing, and habitat alterations. Temporary immersion systems (TISs) have proven effective for large-scale propagation in various protected species, offering potential for ex situ conservation and population reinforcement of V. ucriana. This study aimed to establish a bioreactor-based micropropagation protocol for shoot multiplication and compare the efficacy of a TIS with that of conventional solid culture medium (SCM). Three different plant growth regulators (PGRs) were also compared: 6-benzylaminopurine (BA), zeatin, and meta-topolin-9-riboside (mTR). The starting material originated from seeds collected from mother plants in their natural environment. The best growth outcomes (in terms of shoot multiplication, shoot length, and relative growth rate) were achieved using THE RITA® TIS, with BA (0.2 mg/L) and mTR (0.5 or 0.8 mg/L) outperforming SCM. Anomalous or hyperhydric shoots were observed with all zeatin treatments (especially with 0.8 mg/L) in both the TIS and SCM, suggesting that this cytokinin is unsuitable for V. ucriana biomass production. The rooting phase was significantly improved by transferring propagules onto rockwool cubes fertilized with Hoagland solution. This approach yielded more robust roots in terms of number and length compared to the conventional agar-based medium supplemented with indole-3-butyric acid (IBA). Flow cytometry analysis confirmed the genetic fidelity of the regenerants from the optimal PGR treatments, showing that all plantlets maintained the diploid ploidy level of their maternal plants. Over 90% of the in vitro derived plantlets were successfully acclimatized to greenhouse conditions. This paper represents the first report of V. ucriana biomass multiplication using a RITA^® bioreactor. The stability of the regenerants, confirmed by nuclei quantification via cytofluorimetry, provides guidance in establishing a true-to-type ex situ population, supporting conservation and future reinforcement efforts. Full article

With the expansion of cities and the development of industries, heavy metal pollution has caused a serious negative impact on the growth and development of animals and plants, which has become a global economic and social problem. Cadmium (Cd) is one of the main heavy metals that threaten the growth and development of plants, and it can lead to the imminent extinction of plants in severe cases. The part of upper reaches of the Yangtze River in China from Yibin to the Three Gorges Reservoir has been contaminated with varying degrees of Cd, and a rare and endangered plant called Myricaria laxiflora also lives in this area. The stress of heavy metal Cd on M. laxiflora populations is still unknown. In this study, we used the seedlings of M. laxiflora as materials, and adopted conventional physiological and biochemical analyses to characterize the morphological and physiological responses of M. laxiflora under different concentrations of Cd, and analyzed its response to Cd stress at the transcriptional level. The results showed that the wild population of M. laxiflora was stressed by the heavy metal Cd. High concentrations of Cd can inhibit the growth of M. laxiflora. M. laxiflora responded to the Cd stress through resistance substances such as malondialdehyde (MDA), hydrogen peroxide (H₂O₂), superoxide dismutase (SOD), catalase (CAT), and phytohormones such as auxin (IAA), gibberellin (GA) and abscisic acid (ABA). Transcriptome analysis was carried out on M. lasiflora seedlings exposed to 24 h, 48 h, and 72 h of Cd stress. Compared with 0 h (control), 2470, 11,707, and 11,733 differential expressed genes (DEGs) were identified, respectively. Among them, the number of down-regulated genes is more than the number of up-regulated genes. Transcriptome analysis showed that the upregulated genes were mainly enriched in MAPK signaling pathway, ethylene-induced pathway, ABA response pathway and other pathways, and the downregulated genes were mainly enriched in photosynthesis related pathways. Cd stress affected photosynthesis of M. laxiflora, and M. laxiflora may activate the MAPK signaling pathway through ethylene and ABA to improve the ability of Cd stress tolerance. These results reveal morphological changes, physiological and biochemical reactions and related key response pathways of M. laxiflora during Cd stress. It can provide a reference basis for habitat restoration and selection of wildlife environments for M. laxiflora. Full article

Florida, USA, has 215 endemic or near-endemic plant species, most of which are found in scrubland and pine flatwood habitats and some of which are globally threatened or endangered. Florida is also one of the most rapidly urbanizing states in the United States, and natural lands are being rapidly replaced by urban development in this state. Conservation easements and nature preserves are two tools for sustaining biodiversity in urbanizing landscapes. This collection of images documents observational research on rare and endemic wildflower species in the nature preserves of Hillsborough County, Florida (population of 1.5 million), part of the larger Tampa metropolitan area (population of 3.2 million). A two-year survey of wildflowers in 27 nature preserves dispersed throughout the county’s total 3.3 km² area observed 410 species across 97 families. Of these 410 species, there were 19 species endemic to Florida, including the critically globally endangered Florida goldenaster (Chrysopsis floridana). Each of these endemic species relies on the unique soil and hydrologic conditions of the Florida scrubland and flatwood ecosystems, and preservation of these lands amidst urban development is critical for their conservation. The objective of this work is to document the role of the nature preserves as habitats for rare and endemic wildflower species, with the goal of providing science-based support for maintaining preserve land within and near urbanizing areas. Full article

Curcuma larsenii Maknoi & Jenjitikul is a member of the Zingiberaceae family, possessing significant pharmacological potential, although it has become endangered through the abuse of resources. This research article delineates the findings of the in vitro propagation, transplantation, and phytochemical profiles of C. larsenii, a rare plant species in Thailand. Microshoots measuring 1 cm in length were used as explants for the induction of shoots and roots in both solid and liquid Murashige and Skoog medium, incorporating various concentrations of cytokinins (6-benzylamino-purine (BA), 6-furfurylaminopurine (kinetin), thidiazuron (TDZ)) and auxins (1-naphthaleneacetic acid (NAA) and indole-3-acetic acid (IAA)) over a duration of 8 weeks. This study assessed the total phenolic content, total flavonoid content, and antioxidant activity via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays and conducted high-performance liquid chromatography (HPLC) analysis. The highest number of shoots was recorded in solid and liquid media containing MS medium enriched with 2 mg/L BA and 0.5 mg/L NAA, as well as 2 mg/L BA and 0.5 mg/L IAA, yielding 5.40 and 8.80 shoots/explant, respectively. The biggest roots/explant induction of 9.20 was attained using the liquid MS medium supplemented with 4 mg/L BA and 0.5 mg/L IAA. The highest survival rate (100%) was recorded when tissue culture plantlets were transplanted into a mixture of sand and soil (1:1). In vitro-cultivated plants exhibited superior total phenolic content relative to wild plants. Leaf extracts of C. larsenii exhibited markedly superior antioxidant activity compared to other plant organs from both in vitro and wild specimens. C. larsenii wild plants and in vitro plants generated phenolic acids and flavonoids and exhibited antioxidant activity, demonstrating a biotechnological alternative for the acquisition of bioactive substances. Full article

Camellia luteoflora is a rare and endangered plant endemic to China. It has high ornamental and potential economic and medicinal value, and is an important germplasm resource of Camellia. To understand the distributions and differences in metabolites from different parts of C. luteoflora, in this study, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to examine the types and contents of chemical constituents in five organs of C. luteoflora: roots, stems, leaves, flowers, and fruits. The results showed that a total of 815 metabolites were identified in the five organs and were classified into 18 main categories, including terpenoids (17.1%), amino acids (10.4%), flavonoids (10.3%), sugars and alcohols (9.8%), organic acids (9.0%), lipids (7.1%), polyphenols (4.8%), alkaloids (4.8%), etc. A total of 684 differentially expressed metabolites (DEMs) in five organs were obtained and annotated into 217 KEGG metabolic pathways, among which metabolic pathways, ABC transporters, the biosynthesis of cofactors, and the biosynthesis of amino acids were significantly enriched. In DEMs, flowers are rich in flavonoids, polyphenols, organic acids, and steroids; fruits are rich in amino acids, alkaloids, vitamins, and xanthones; stems are rich in lignans; and leaves have the highest relative content of phenylpropanoids, ketoaldehydic acids, quinones, sugars and alcohols, terpenoids, coumarins, lipids, and others; meanwhile, the metabolite content is lower in roots. Among the dominant DEMs, 58 were in roots, including arachidonic acid, lucidone, isoliquiritigenin, etc.; 75 were in flowers, including mannose, shikimic acid, d-gluconic acid, kaempferol, etc.; 45 were in the fruit, including pterostilbene, l-ascorbic acid, riboflavin, etc.; 27 were in the stems, including salicylic acid, d-(-)-quinic acid, mannitol, (-)-catechin gallate, etc.; there was a maximum number of 119 dominant metabolites in the leaves, including oleanolic acid, l-glucose, d-arabitol, eugenol, etc. In sum, the rich chemical composition of C. luteoflora and the significant differences in the relative contents of metabolites in different organs will provide theoretical references for the study of tea, flower tea, edible oil, nutraceuticals, and the medicinal components of C. luteoflora. Full article

China’s rare and endangered bamboo species belonging to the Indocalamus genus, specifically Indocalamus decorus Q. H. Dai, Indocalamus hirsutissimus Z. P. Wang & P. X. Zhang, and Indocalamus pedalis (Keng) P. C. Keng, possess notable value in biodiversity conservation and have significant potential for use in landscape design. Using an enhanced MaxEnt model, this study forecasted shifts in the species’ potential range under four separate climate scenarios (SSP1-RCP2.6, SSP2-RCP4.5, SSP3-RCP7.0, and SSP5-RCP8.5), considering both the historical period (1970–2000, referred to as “the current period”) and upcoming timeframes (2021–2040, 2041–2060, 2061–2080, and 2081–2100). The analysis disclosed that the present total potential habitat area for these species is approximately 251.79 × 10⁴ km², with high, medium, and low suitability areas occupying 0.15 × 10⁴ km², 125.39 × 10⁴ km², and 126.26 × 10⁴ km², respectively. The minimum temperature of the coldest month emerged as the critical determinant of their potential habitat distribution. Expected climate changes are likely to increase the suitable habitat for these species, although areas with low suitability might slightly diminish, with Guizhou and Chongqing showing the least impact. The distribution centers of suitable habitats for the three plant species consistently exhibit a westward shift under various climate scenarios. These results contribute valuable insights for the spatial distribution, continuous monitoring, sustainable management, and ex situ conservation in response to climate change. Full article

In order to understand the bias and main affecting factors of codon usage in the plastid genome of Diplandrorchis sinica, which is a rare and endangered plant species in the Orchidaceae family, the complete plastid genome sequence of D. sinica was downloaded from the GenBank database and 20 protein-coding sequences that met the analysis requirements were finally selected. The GC content, length of the amino acid (Laa), relative synonymous codon usage (RSCU), and effective number of codon (ENC) of each gene and codon were calculated using the CodonW and EMBOSS online programs. Neutral plot analysis, ENC-plot analysis, PR2-plot analysis, and correspondence analysis were performed using Origin Pro 2024 software, and correlation analysis between various indicators was performed using SPSS 23.0 software. The results showed that the third base of the codon in the plastid genome of D. sinica was rich in A and T, with a GC₃ content of 27%, which was lower than that of GC₁ (45%) and GC₂ (39%). The ENC value ranged from 35 to 57, with an average of 47. The codon usage bias was relatively low, and there was a significant positive correlation between ENC and GC₃. There were a total of 32 codons with RSCU values greater than 1, of which 30 ended with either A or U. There were a total of nine optimal codons identified, namely, UCU, UCC, UCA, GCA, UUG, AUA, CGU, CGA, and GGU. This study indicated that the dominant factor affecting codon usage bias in the plastid genome of D. sinica was natural selection pressure, while the impact of base mutations was limited. The codon usage patterns were not closely related to gene types, and the distribution of photosynthetic system genes and ribosomal protein-coding gene loci was relatively scattered, indicating significant differences in the usage patterns of these gene codons. In addition, the codon usage patterns may not be related to whether the plant is a photosynthetic autotrophic or heterotrophic nutritional type. The results of this study could provide scientific references for the genomic evolution and phylogenetic research of plant species in the family Orchidaceae. Full article