Testing the elemental defense hypothesis with a woody plant species: Cadmium accumulation protects Populus yunnanensis from leaf herbivory and pathogen infection

Defense of Cabbages against Herbivore Cutworm Spodoptera litura under Cd Stress and Insect Herbivory Stress simultaneously

Biotic (e.g., heavy metal) and abiotic stress (e.g., insect attack) can affect plant chemical defense, but little is known about the changes in plant defense when they occur concurrently. Herein, the impacts of heavy metal cadmium (Cd) stress and insect herbivory stress on the direct and indirect defense of two cultivar cabbages of Brassica campestris, the low-Cd cultivar Lvbao701 and the high-Cd cultivar Chicaixin No.4, against the herbivore cutworm Spodoptera litura were investigated. Although 10 mg kg-1 Cd stress alone inhibited leaf secondary metabolites (total phenolics, flavonoids), it also reduced the feeding rate and odor selection of S. litura towards both cultivar cabbages, especially for Lvbao701, by increasing leaf Cd content and repellent volatile organic compounds (VOCs) (6-methyl-5-hepten-2-one, 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione), and reducing soluble sugar and attractive VOCs (3-methyl-3-pentanol, 2,5-hexanedione, tetradecanal). Under 2.5 mg kg-1 Cd and herbivory stress, although leaf total phenolics and flavonoids increased significantly, the feeding rate and odor selection of S. litura towards both cultivar cabbages increased, especially for Chicaixin No.4, indicating that the chemical defense of cabbages was depressed. Therefore, Cd stress alone improved the insect resistance of cabbages, whereas herbivory stress weakened the enhanced cabbages defence by Cd stress. The low-Cd cultivar Lvbao701 presented stronger insect resistance than Chicaixin No.4, suggesting that Lvbao701 application in Cd-polluted soil can not only decrease Cd transmission to higher levels in the food chain but also reduce pest occurrence.

Cadmium induced defense enhance the invasive potential of Wedelia trilobata under herbivore infestation

Cadmium (Cd) pollution is on the rise due to rapid urbanization, which emphasize the potential adverse effects on plant biodiversity and human health. Wedelia as a dominant invasive species, is tested for its tolerance to Cd-toxicity and herbivore infestation. We investigate defense mechanism system of invasive Wedelia trilobata and its native congener Wedelia chinensis against the Cd-pollution and Spodoptera litura infestation. We found that Cd-toxicity significantly increase hydrogen peroxide (H2O2), Malondialdehyde (MDA) and hydroxyl ions (O2•) in W. chinensis 20.61%, 4.78% and 15.68% in leave and 27.44%, 25.52% and 30.88% in root, respectively. The photosynthetic pigments (Chla, Chla and Caro) and chlorophyll florescence (Fo and Fv/Fm) declined by (60.23%, 58.48% and 51.96%), and (73.29% and 55.75%) respectively in W. chinensis and (44.76%, 44.24% and 44.30%), and (54.66% and 45.36%) in W. trilobata under Cd treatment and S. litura. Invasive W. trilobata had higher enzymatic antioxidant SOD 126.9/71.64%, POD 97.24/94.92%, CAT 53.99/25.62% and APX 82.79/50.19%, and nonenzymatic antioxidant ASA 10.47/16.87%, DHA 15.07/27.88%, GSH 15.91/10.03% and GSSG 13.56/17.93% activity in leaf/root, respectively. Overall, W. trilobata accumulate higher Cd content 55.41%, 50.61% and 13.95% in root, shoot and leaf tissues respectively, than its native congener W. chinensis. While, nutrient profile of W. chinensis reveals less uptake of Fe, Cu and Zn than W. trilobata. W. trilobata showed efficient alleviation of oxidative damage through upregulating the genes related to key defense such as SOD, POD, CAT, APX, GR, PROL, FLV, ABA and JAZ, and metal transporter in leaves, shoot and root tissues, respectively. Conclusively, W. trilobata efficiently employed Cd-triggered defense for successful invasion, even under S. litura infestation, in Cd-contaminated soil.

Transcriptome analysis reveals cadmium exposure enhanced the isoquinoline alkaloid biosynthesis and disease resistance in Coptis chinensis

Coptis chinensis Franch is a perennial herb from the Ranunculaceae family with a long history of medicinal use. As the medicinal part, the rhizome of coptis often accumulates excessive cadmium (Cd) even at low concentrations in the soil, which not only compromises its medicinal safety but also raises concerns about adverse effects on human health. Therefore, effective strategies are needed to mitigate this accumulation and ensure its safe use in traditional medicine. This study utilized transcriptome profiling and physiological analysis to explore molecular mechanisms associated with ecological significance and the active accumulation of Cd in C. chinensis. The response to Cd in C. chinensis was assessed through RNA sequencing, Cd determination and isoquinoline alkaloid measurement using its roots, stems, and leaves. The transcriptome revealed, a total of 2667, 2998, or 2815 up-regulated deferentially expressed genes in roots, stems or leaves in response to Cd exposure. Furthermore, we identified phenylpropanoid and isoquinoline alkaloid biosynthesis as the key pathways response to Cd exposure, which suggests that C. chinensis may improve its tolerance to Cd through regulating the phenylpropanoid biosynthesis pathway. Under Cd exposure, plant-pathogen interaction in leaves was identified as the key pathway, which indicates that upregulation of genes involved in plant-pathogen interaction could enhance disease resistance in C. chinensis. WGCNA analysis identified WRKY8 (Cluster-55763.31419) and WRKY47 (Cluster-55763.221590) as potential regulators of secondary metabolic synthesis and plant-pathogen interaction pathway in C. chinensis triggered by Cd. The measurement of berberine, coptisine, palmatine, and epiberberine also demonstrated that Cd simulated the four isoquinoline alkaloids in roots. Therefore, our study not only presented a transcriptome expression profiles that revealed significant upregulation of genes involved in metal transport and detoxification pathways but also suggested a possible mechanism to cope with Cd accumulation. This knowledge provides a new insight into gene manipulation for controlling Cd accumulation, enhancing resistance and promoting synthesis of secondary metabolites with potential medicinal properties in other medicinal plant species.

Soil cadmium pollution facilitated the invasion of alligator weed through enhanced herbivore resistance and competitive ability over a congeneric species

A number of invasive plant species, such as Alternanthera philoxeroides, have been documented to be able to accumulate trace metal elements in their tissues. Since metal accumulation in plants can serve as a defence against herbivores, we hypothesized that metal pollution will increase herbivore resistance of metal-accumulating invasive plant species and such a benefit will grant them a competitive advantage over local co-occurring plants. In this study, we compared the differences in plant growth and herbivore feeding preference between A. philoxeroides and its native congener Alternanthera sessilis in single and mixed cultures with and without soil cadmium (Cd) pollution. The results showed that A. philoxeroides plants were more tolerant to Cd stress and accumulated more Cd in the leaves than A. sessilis. Cd exposure increased the resistance of A. philoxeroides against a specialist and a generalist herbivore compared with A. sessilis. Competition experiments indicated that Cd stress largely increased the competitive advantage of A. philoxeroides over A. sessilis with or without herbivore pressures. The differences in herbivore resistance between the two plant species under soil Cd stress are most likely due to the deterring effect of Cd accumulation and Cd-enhanced mechanical defences rather than changes in leaf specialized metabolites.

Editing Metabolism, Sex, and Microbiome: How Can We Help Poplar Resist Pathogens?

Poplar (Populus) is a genus of woody plants of great economic value. Due to the growing economic importance of poplar, there is a need to ensure its stable growth by increasing its resistance to pathogens. Genetic engineering can create organisms with improved traits faster than traditional methods, and with the development of CRISPR/Cas-based genome editing systems, scientists have a new highly effective tool for creating valuable genotypes. In this review, we summarize the latest research data on poplar diseases, the biology of their pathogens and how these plants resist pathogens. In the final section, we propose to plant male or mixed poplar populations; consider the genes of the MLO group, transcription factors of the WRKY and MYB families and defensive proteins BbChit1, LJAMP2, MsrA2 and PtDef as the most promising targets for genetic engineering; and also pay attention to the possibility of microbiome engineering.

Advances in the Involvement of Metals and Metalloids in Plant Defense Response to External Stress

Plants, as sessile organisms, uptake nutrients from the soil. Throughout their whole life cycle, they confront various external biotic and abiotic threats, encompassing harmful element toxicity, pathogen infection, and herbivore attack, posing risks to plant growth and production. Plants have evolved multifaceted mechanisms to cope with exogenous stress. The element defense hypothesis (EDH) theory elucidates that plants employ elements within their tissues to withstand various natural enemies. Notably, essential and non-essential trace metals and metalloids have been identified as active participants in plant defense mechanisms, especially in nanoparticle form. In this review, we compiled and synthetized recent advancements and robust evidence regarding the involvement of trace metals and metalloids in plant element defense against external stresses that include biotic stressors (such as drought, salinity, and heavy metal toxicity) and abiotic environmental stressors (such as pathogen invasion and herbivore attack). We discuss the mechanisms underlying the metals and metalloids involved in plant defense enhancement from physiological, biochemical, and molecular perspectives. By consolidating this information, this review enhances our understanding of how metals and metalloids contribute to plant element defense. Drawing on the current advances in plant elemental defense, we propose an application prospect of metals and metalloids in agricultural products to solve current issues, including soil pollution and production, for the sustainable development of agriculture. Although the studies focused on plant elemental defense have advanced, the precise mechanism under the plant defense response still needs further investigation.

First record of the complete mitochondrial genome of Botyodes diniasalis (Walker, 1859) (Lepidoptera: Crambidae)

We performed the first sequencing of the complete mitogenome of Botyodes diniasalis by high-throughput sequencing. A circular DNA molecule of 15,219 bp in size, encoding 2 rRNAs, 22 tRNAs, and 13 PCGs, contains a non-coding AT-rich region. The overall nucleotide composition of the genome is A (39.5%), T (41.3%), C (11.3%), and G (7.8%). Phylogenetic analysis based on mitogenomic data suggest that the species B. diniasalis has a close evolutionary relationship with B. principalis in Margaroniini. The complete mitogenome of B. diniasalis will serve as a valuable resource for future studies on evolution, taxonomy, genetic conservation, and utilization of Botyodes.

A review of plants strategies to resist biotic and abiotic environmental stressors

Plants exposed to a variety of abiotic and biotic stressors including environmental pollution and global warming pose significant threats to biodiversity and ecosystem services. Despite substantial literature documenting how plants adapt to distinct stressors, there still is a lack of knowledge regarding responses to multiple stressors and how these affects growth and development. Exposure of plants to concurrent biotic and abiotic stressors such as cadmium and drought, leads to pronounced inhibition in above ground biomass, imbalance in oxidative homeostasis, nutrient assimilation and stunted root growth, elucidating the synergistic interactions of multiple stressors culminating in adverse physiological outcomes. Impact of elevated heavy metal and water deficit exposure extends beyond growth and development, influencing the biodiversity of the microenvironment including the rhizosphere nutrient profile and microbiome. These findings have significant implications for plant-stress interactions and ecosystem functioning that prompt immediate action in order to eliminate effect of pollution and address global environmental issues to promote sustainable tolerance for multiple stress combinations in plants. Here, we review plant tolerance against stress combinations, highlighting the need for interdisciplinary approaches and advanced technologies, such as omics and molecular tools, to achieve a comprehensive understanding of underlying stress tolerance mechanisms. To accelerate progress towards developing stress-tolerance in plants against multiple environmental stressors, future research in plant stress tolerance should adopt a collaborative approach, involving researchers from multiple disciplines with diverse expertise and resources.

Defense response of Fraxinus mandshurica seedlings to Hyphantria cunea larvae under Cd stress: A contradiction between attraction and resistance

Heavy metal pollution, as a common and serious environmental problem worldwide, has been regarded as an abiotic stimulus that can affect plant insect resistance and pest occurrence. This study evaluated the defense response of Fraxinus mandshurica seedlings to Hyphantria cunea larvae under Cd stress, with consideration given to chemical defense, physical defense, and elemental defense. Our results showed that the H. cunea larvae had a strong preference for Cd-treated F. mandshurica seedlings, but there was a significant reduction in body weight and survival rate in larvae that fed on leaves of Cd-treated seedlings. Under Cd treatment, the increase in attractant metabolites (e.g., styrene, dibutyl phthalate, and d-limonene) and the decrease in repellent metabolites (e.g., aromadendrene, heptadecane, and camphene) in leaf volatiles were responsible for the high attractant activity to H. cunea larvae. Based on leaf physicochemical properties, tissue structure, and phenolic acid content, an overall reduction in physical defense, chemical defense and their combination in F. mandshurica seedlings exposed to Cd stress was identified by Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) analysis. Elemental defense occurred in Cd-treated F. mandshurica seedlings, as evidenced by the high concentration of Cd in leaves and H. cunea larvae under Cd treatment. Taken together, these findings demonstrate that under Cd stress, elemental defense replaces the dominant role of basic defense in F. mandshurica seedlings and accounts for the enhanced ability to defend against H. cunea larvae.

Cadmium contributes to heat tolerance of a hyperaccumulator plant species Sedum alfredii

Hyperaccumulators are plant species that tolerate and accumulate very high concentrations of toxic metals, including Cd. Hyperaccumulation of heavy metals is reported to benefit plant biotic resistance; however, no prior study has examined the possible role of toxic metals on abiotic stress resistance in hyperaccumulators. A preliminary experiment found that Cd significantly improved plant growth of a hyperaccumulator, Sedum alfredii Hance, under heat stress. This study investigated the possible role of Cd in S. alfredii's heat resistance, using infrared thermography, transmission electron microscopy (TEM), real-time quantitative polymerase chain reaction (RTqPCR), and high-throughput sequencing. The results showed that high temperatures irreversibly damaged stomatal function, chloroplast structure, photosynthesis in S. alfredii, and lowered survival rates to 25%. However, Cd application significantly decreased the leaf temperature of S. alfredii and increased the survival rate to 75%. Cd penetrated the guard cells, restored stomatal function, and mitigated excessive water loss from S. alfredii under heat stress. Moreover, it activated antioxidant enzymes, promoted phytohormone biosynthesis, and upregulated a series of unigenes, thereby augmenting heat resistance in S. alfredii. These results indicate that Cd effectively improved thermotolerance in S. alfredii by regulating stomatal movement and antioxidant systems via upregulation of phytohormones and heat shock proteins.

Effects of gallic acid and Zn, Cu, and Ni on antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis

The effects of copper, nickel, and zinc and the potent antioxidant gallic acid on the antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis subsp. kurstaki have been identified in this study. With metal exposure, all the enzyme activities have increased. Antagonistic effects were observed in the combination of gallic acid with all three metals on the activities of superoxide dismutase and catalase. In glutathione peroxidase activity, an antagonistic effect was observed in gallic acid plus nickel group, while there was a synergistic effect for gallic acid plus zinc and gallic acid plus copper. Activities of these enzymes in larvae exposed only to the metals increased in the infected groups; while exposure to gallic acid alone elicited a decrease. As a consequence, it was found that enzyme activities were affected by both metals and gallic acid and infection.

Soil cadmium stress reduced host plant odor selection and oviposition preference of leaf herbivores through the changes in leaf volatile emissions

The Elemental defense hypothesis suggested that metal accumulation in plant tissues could serve as direct defense to reduce herbivore feeding preference as metals are toxic to phytophagous insects. However, the indirectly defensive role of heavy metals on host plant odor selection and oviposition preference of leaf herbivores through the changes in leaf volatile organic compounds (VOCs) is still unknown. In this study, we used a local woody plant species, Populus yunnanensis, to investigate whether soil cadmium (Cd) stress could affect plant VOC production and whether Cd-mediated changes in leaf VOC emissions will further influence the host plant odor and oviposition preferences of female adults of a specialist and a generalist herbivore species. The results clearly showed that the soil Cd stress could prominently induce leaf total VOC emissions of P. yunnanensis and such induction was positively correlated with leaf Cd accumulation. Herbivore olfactometer bioassays further demonstrated that the VOCs released by P. yunnanensis under Cd exposure are far less attractive to both of the specialist and generalist female adults compared to control plants, leading to significant reduction in oviposition on Cd-treated plants. Moreover, the host plant odor selection and oviposition preference of the two herbivore species were all negatively correlated with leaf total VOC emissions, which confirmed the defensive role of Cd-induced VOCs for deterring the female insects. The result will extend the existing knowledge of the Elemental defense hypothesis and provide new insight into predicting the herbivore damage level of poplar species that naturally occurred in metal-polluted habitats.

Sexual differences in above- and belowground herbivore resistance between male and female poplars as affected by soil cadmium stress

Dioecious plant species presented sexual differences in metal accumulation and allocation between male and female conspecifics that grown on metal contaminated soil. As the Elemental defense hypothesis postulates that metals accumulated in plant tissues could protect plants from herbivory, whether such sexual dimorphism in response to metal stress of a dioecious plant will lead to differences in herbivore resistance between male and female conspecifics is still unknown. In this study, we used female and male siblings of Populus deltoides to investigate the effect of plant sex on the growth and feeding preferences of four leaf herbivores and a root herbivore under soil cadmium (Cd) stress. The results showed that the male plants accumulated significantly higher Cd in the leaves while the females allocated more Cd in the roots. Leaf herbivores fed on male leaves grew worse than those fed on female leaves under Cd exposure, while the root herbivore showed the opposite results. In addition, all leaf herbivores strongly preferred the leaves from Cd-stressed female plants than male ones. The quantification of gene expression further showed that Cd stress could significantly upregulate more genes involved in Cd uptake, transport and detoxification pathways in male leaves and female roots. In combination with the correlation tests, we postulated that such sexual differences in herbivore resistance between the two plant sexes was most likely due to the different Cd allocation patterns in plant leaves and roots.

The elemental defense effect of cadmium on Alternaria brassicicola in Brassica juncea

BACKGROUND

The elemental defense hypothesis states a new defensive strategy that hyperaccumulators defense against herbivores or pathogens attacks by accumulating heavy metals. Brassica juncea has an excellent ability of cadmium (Cd) accumulation. However, the elemental defense effect and its regulation mechanism in B. juncea remain unclear.

RESULTS

In this study, we profiled the elemental defense effect and the molecular regulatory mechanism in Cd-accumulated B. juncea after Alternaria brassicicola infection. B. juncea treated with 180 mg Kg^- 1 DW CdCl₂ 2.5H₂O exhibited obvious elemental defense effect after 72 h of infection with A. brassicicola. The expression of some defense-related genes including BjNPR1, BjPR12, BjPR2, and stress-related miRNAs (miR156, miR397, miR398a, miR398b/c, miR408, miR395a, miR395b, miR396a, and miR396b) were remarkably elevated during elemental defense in B. juncea.

CONCLUSIONS

The results indicate that Cd-accumulated B. juncea may defend against pathogens by coordinating salicylic acid (SA) and jasmonic acid (JA) mediated systemic acquired resistance (SAR) and elemental defense in a synergistic joint effect. Furthermore, the expression of miRNAs related to heavy metal stress response and disease resistance may regulate the balance between pathogen defense and heavy metal stress-responsive in B. juncea. The findings provide experimental evidence for the elemental defense hypothesis in plants from the perspectives of phytohormones, defense-related genes, and miRNAs.

Effects of exogenous spermidine on poplar resistance to leaf and root herbivory as affected by soil cadmium stress

Elemental defense hypothesis (EDH) proposed that metal accumulation in plants could increase plant resistance to herbivores. However, the over-accumulation of metals in low-accumulators such as woody plants will cause adverse effects on plant health. Thus, the application of EDH on low-accumulators in metal contaminated areas is strongly limited. Since the supplement of exogenous spermidine (Spd) was reported to alleviate metal-induced toxicity in plants while stimulating metal accumulation in plant tissues, we hypothesized that such application will further improve plant resistance to herbivores. In this study, we employed a woody plant species, Populus yunnanensis, to test this hypothesis. We first tested a Spd concentration series applied on plants subjected to soil cadmium (Cd) stress and found that the 1 mM Spd strongly promoted plant growth while stimulated Cd accumulation in plant leaves and roots. We further conducted herbivore bioassays to test the growth performance and feeding preference of two leaf herbivore species and a root herbivore species that fed on plants from different treatments. The results showed that the inhibition effect of Cd stressed-plants on herbivore growth was significantly magnified by the addition of Spd. The growth weight of all the three tested herbivores were negatively correlated with increased Cd concentrations in plant tissues. In addition, the feeding preferences of the two leaf herbivore species were strongly repelled by leaf discs from Cd-treated plants with Spd supplement. The results suggested that the application of exogenous Spd at a certain dose could enhance elemental defense of plants against herbivory.

The susceptibility of Lymantria dispar larvae to Beauveria bassiana under Cd stress: A multi-omics study

Insect susceptibility to entomopathogenic microorganisms under heavy metal stress, as well as its regulatory mechanism is still poorly understood. This study aims to investigate the susceptibility of gypsy moth larvae to Beauveria bassiana under cadmium (Cd) stress (at 3.248 or 44.473 mg Cd/kg fresh food), and reveal the potential molecular mechanisms underlying the Cd effect on the larval susceptibility to B. bassiana via combined transcriptome and proteome analyses. Our results showed that pre-exposure to Cd increased the susceptibility of gypsy moth larvae to B. bassiana, and there was an additive effect between Cd exposure and B. bassiana infection on the larval mortality. Under the Cd stress at low and high concentrations, 138 and 899 differentially expressed genes (DEGs), as well as 514 and 840 differentially expressed proteins (DEPs) were identified, respectively. Immunotoxic effects induced by Cd exposure at the transcription level increased in a negative dose-response manner, with no immunity-related DEGs obtained at the low Cd concentration and a high number of immunity-related DEGs down-regulated at the high Cd concentration. In contrast, a potentially suppressed or stimulated trend in the Toll and Imd signaling pathway at protein level was revealed under low or high concentration of Cd treatment. Analysis of xenobiotics biodegradation-related pathways at both transcription and translation levels revealed that the gypsy moth larvae possessed an efficient homeostasis regulatory mechanism to the low-level Cd exposure, but exhibited a reduced xenobiotics biodegradation capability to the Cd stress at high levels. Together, these findings demonstrate Cd contamination promote the microbial-based biocontrol efficacy, and unravel the molecular regulatory network of heavy metal exposures that affects susceptibility of insects to pathogenic diseases.

Exogenous nitrogen enhances poplar resistance to leaf herbivory and pathogen infection after exposure to soil cadmium stress

Elemental defense hypothesis suggests that toxic metals accumulated in plant tissues could enhance plant defense against herbivores and pathogens. Since over-accumulation of metals in plant organs will pose negative effects on plant health, it is necessary to find a way to alleviate metal-induced toxicity in plants while keeping or even improving plant resistance. Exogenous nitrogen (N) application was reported to have such alleviation effect while stimulating metal accumulation in plant tissues. In this study, we examined whether soil N addition in three different doses to a poplar species under cadmium (Cd) stress can simultaneously improve plant growth and resistance to four herbivorous insects and a leaf pathogen. The results showed that N application to Cd-amended soil prominently enhanced plant growth and leaf Cd accumulation. While N addition in three doses all remarkably reduced herbivore growth than control plants, only the highest N dose exerted stronger inhibition than the sole Cd-treated plants. In the paired-choice experiment, plants supplied with the highest N dose showed an enhanced deterrent effect on herbivore preference than plants exposed to sole Cd. Furthermore, plant resistance to the leaf pathogen infection was strongly enhanced as the levels of N addition increased. Leaf sugar and three main defensive chemicals were not affected by N application implied that such enhanced effect of N on plant resistance was due to increased leaf Cd accumulation. Our results suggested that the application of exogenous N over a certain amount could enhance the resistance of Cd-treated plants to leaf herbivory and pathogen infection.

Anti-osteosarcoma Biological Activity Evaluation and Complete Chloroplast Genome Sequencing of Populus yunnanensis

Recently, the Populus yunnanensis extract has drawn the attention of most researchers, because of their anti-cancer activity. In this present research, the anti-cancer activity of the Populus yunnanensis extract was measured with Cell Counting Kit-8 (CCK-8) detection kit on the cancer cells. Then, the inhibitory activity of the Populus yunnanensis extract on the migration and invasion ability of the cancer cells was also determined in this present research with trans-well assay. Subsequently, to reveal the evolutionary genome evolution evaluation of the Populus yunnanensis and other Populus species, the high-throughput Illumina pair-end sequencing was performed and the chloroplast (cp) genome of Populus yunnanensis was determined, and the phylogenetic analysis was finished as wells. The results of the CCK-8 assay indicated that the Populus yunnanensis extract showed inhibitory effect on the cancer cell viability. Besides, the migration and invasion ability of the cancer cell was also reduced by the Populus yunnanensis extract. The complete chloroplast genome sequence results revealed that the Populus yunnanensis has a 156,505 bp circular cp genome. The phylogenetic analysis further revealed that the Populus yunnanensis has closely relationship with Populus simonii.