Leaf trait association in relation to herbivore defense, drought resistance, and economics in a tropical invasive plant.

PREMISE: Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species. METHODS: We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense, and drought resistance on 10 introduced populations from Asia and 12 native populations from South and Central America, selected across a broad range of climatic conditions, and grown in a common garden. RESULTS: Species' range and climatic conditions influenced leaf traits, but trait variation across climate space differed between the introduced and native ranges. Traits that confer defense against herbivores and drought resistance were associated with economic strategy, but the patterns differed by range. Plants from introduced populations that were at the fast-return end of the spectrum (high photosynthetic capacity) had high physical defense traits (high trichome density), whereas plants from native populations that were at the fast-return end of the spectrum had high drought escape traits (early leaf senescence and high percentage of withered shoots). CONCLUSIONS: Our results indicate that invasive plants can rapidly adapt to novel environmental conditions. Chromolaena odorata showed multiple different functional trait covariation patterns and clines in the native and introduced ranges. Our results emphasize that interaction between multiple traits or functions should be considered when investigating the adaptive evolution of invasive plants.

Founder effects, post-introduction evolution and phenotypic plasticity contribute to invasion success of a genetically impoverished invader.

Multiple mechanisms may act synergistically to promote success of invasive plants. Here, we tested the roles of three non-mutually exclusive mechanisms-founder effects, post-introduction evolution and phenotypic plasticity-in promoting invasion of Chromolaena odorata. We performed a common garden experiment to investigate phenotypic diversification and phenotypic plasticity of the genetically impoverished invader in response to two rainfall treatments (ambient and 50% rainfall). We used ancestor-descendant comparisons to determine post-introduction evolution and the QST-FST approach to estimate past selection on phenotypic traits. We found that eight traits differed significantly between plants from the invasive versus native ranges, for two of which founder effects can be inferred and for six of which post-introduction evolution can be inferred. The invader experienced strong diversifying selection in the invasive range and showed clinal variations in six traits along water and/or temperature gradients. These clinal variations are likely attributed to post-introduction evolution rather than multiple introductions of pre-adapted genotypes, as most of the clinal variations were absent or in opposite directions from those for native populations. Compared with populations, rainfall treatments explained only small proportions of total variations in all studied traits for plants from both ranges, highlighting the importance of heritable phenotypic differentiation. In addition, phenotypic plasticity was similar for plants from both ranges although neutral genetic diversity was much lower for plants from the invasive range. Our results showed that founder effects, post-introduction evolution and phenotypic plasticity may function synergistically in promoting invasion success of C. odorata.

Species composition, functional and phylogenetic distances correlate with success of invasive Chromolaena odorata in an experimental test.

Biotic resistance may influence invasion success; however, the relative roles of species richness, functional or phylogenetic distance in predicting invasion success are not fully understood. We used biomass fraction of Chromolaena odorata, an invasive species in tropical and subtropical areas, as a measure of 'invasion success' in a series of artificial communities varying in species richness. Communities were constructed using species from Mexico (native range) or China (non-native range). We found strong evidence of biotic resistance: species richness and community biomass were negatively related with invasion success; invader biomass was greater in plant communities from China than from Mexico. Harvesting time had a greater effect on invasion success in plant communities from China than on those from Mexico. Functional and phylogenetic distances both correlated with invasion success and more functionally distant communities were more easily invaded. The effects of plant-soil fungi and plant allelochemical interactions on invasion success were species-specific.

Copper-Catalyzed Three-Component Tandem Cyclization for One-Pot Synthesis of 1,4-Benzothiazines.

A copper-catalyzed three-component tandem reaction has been developed for the convenient and practical synthesis of 1,4-benzothiazines. A variety of terminal alkynes and 2-iodo/bromophenyl isothiocyanates underwent this one-pot cyclization with aqueous ammonia to afford 1,4-benzothiazines in moderate to good yields.

Integrating novel chemical weapons and evolutionarily increased competitive ability in success of a tropical invader.

The evolution of increased competitive ability (EICA) hypothesis and the novel weapons hypothesis (NWH) are two non-mutually exclusive mechanisms for exotic plant invasions, but few studies have simultaneously tested these hypotheses. Here we aimed to integrate them in the context of Chromolaena odorata invasion. We conducted two common garden experiments in order to test the EICA hypothesis, and two laboratory experiments in order to test the NWH. In common conditions, C. odorata plants from the nonnative range were better competitors but not larger than plants from the native range, either with or without the experimental manipulation of consumers. Chromolaena odorata plants from the nonnative range were more poorly defended against aboveground herbivores but better defended against soil-borne enemies. Chromolaena odorata plants from the nonnative range produced more odoratin (Eupatorium) (a unique compound of C. odorata with both allelopathic and defensive activities) and elicited stronger allelopathic effects on species native to China, the nonnative range of the invader, than on natives of Mexico, the native range of the invader. Our results suggest that invasive plants may evolve increased competitive ability after being introduced by increasing the production of novel allelochemicals, potentially in response to naïve competitors and new enemy regimes.

Evolutionary increases in defense during a biological invasion.

Invasive plants generally escape from specialist herbivores of their native ranges but may experience serious damage from generalists. As a result, invasive plants may evolve increased resistance to generalists and tolerance to damage. To test these hypotheses, we carried out a common garden experiment comparing 15 invasive populations with 13 native populations of Chromolaena odorata, including putative source populations identified with molecular methods and binary choice feeding experiments using three generalist herbivores. Plants from invasive populations of C. odorata had both higher resistance to three generalists and higher tolerance to simulated herbivory (shoot removal) than plants from native populations. The higher resistance of plants from invasive populations was associated with higher leaf C content and densities of leaf trichomes and glandular scales, and lower leaf N and water contents. Growth costs were detected for tolerance but not for resistance, and plants from invasive populations of C. odorata showed lower growth costs of tolerance. Our results suggest that invasive plants may evolve to increase both resistance to generalists and tolerance to damage in introduced ranges, especially when the defense traits have low or no fitness costs. Greater defenses in invasive populations may facilitate invasion by C. odorata by reducing generalist impacts and increasing compensatory growth after damage has occurred.

Palladium and copper cocatalyzed tandem N-H/C-H Bond functionalization: synthesis of CF3-containing indolo- and pyrrolo[2,1-a]isoquinolines.

A palladium- and copper-catalyzed tandem N-H/C-H bond functionalization reaction of ortho-(2-chlorovinyl)bromobenzenes with indoles and pyrroles has been developed. A variety of CF(3)-containing indolo- and pyrrolo[2,1-a]isoquinolines were prepared in moderate to good yields via the cyclization of 1-bromo-2-(2-chloro-3,3,3-trifluoroprop-1-enyl)benzenes with indoles and pyrroles.

Plasma D-dimer as a predictor of intraluminal thrombus burden and progression of abdominal aortic aneurysm.

AIM: Intraluminal thrombus (ILT) is presented in most abdominal aortic aneurysms (AAAs) and is suggested to promote AAA expansion. D-dimer, a breakdown product in the thrombus remodeling, may have prognostic value for AAA. This study investigated the interrelation between plasma D-dimer level, ILT volume, AAA size and progression. MAIN METHODS: This was a retrospective observational study that involved 181 patients with infra-renal AAA. They were divided into small and large AAA groups according to AAA diameter. 24 of them had repeated abdominal computed tomography angiography (CTA) scan and were divided into slow-growing and fast-growing AAA groups according to the median value of AAA growth rate. Baseline and follow-up plasma D-dimer level, maximum diameter of AAA, total infra-renal aortic volume and ILT volume were analyzed. KEY FINDINGS: Plasma D-dimer level was positively correlated with ILT volume (R = 0.382, P < 0.001) and maximum diameter of AAA (R = 0.442, P < 0.001). Increasing value of plasma D-dimer was positively associated with the accelerated growth rate of AAA (R = 0.720, P < 0.01). ILT volume showed positive correlation with maximum diameter (R = 0.859, P < 0.001) and growth rate of AAA (R = 0.490, P < 0.05). After adjusting the baseline ILT volume, the positive correlations remained to be statistically significant between plasma D-dimer level and AAA size (R = 0.200, P < 0.05), as well as increasing value of plasma D-dimer and growth rate of AAA (R = 0.642, P < 0.05). SIGNIFICANCE: Plasma D-dimer level reflected ILT burden in AAAs. Plasma D-dimer level and ILT volume were positively correlated with AAA size. Increasing value of plasma D-dimer and baseline ILT volume could be predictors of AAA progression.

Nonclassic functions of human topoisomerase I: genome-wide and pharmacologic analyses.

The biological functions of nuclear topoisomerase I (Top1) have been difficult to study because knocking out TOP1 is lethal in metazoans. To reveal the functions of human Top1, we have generated stable Top1 small interfering RNA (siRNA) cell lines from colon and breast carcinomas (HCT116-siTop1 and MCF-7-siTop1, respectively). In those clones, Top1 is reduced approximately 5-fold and Top2alpha compensates for Top1 deficiency. A prominent feature of the siTop1 cells is genomic instability, with chromosomal aberrations and histone gamma-H2AX foci associated with replication defects. siTop1 cells also show rDNA and nucleolar alterations and increased nuclear volume. Genome-wide transcription profiling revealed 55 genes with consistent changes in siTop1 cells. Among them, asparagine synthetase (ASNS) expression was reduced in siTop1 cells and in cells with transient Top1 down-regulation. Conversely, Top1 complementation increased ASNS, indicating a causal link between Top1 and ASNS expression. Correspondingly, pharmacologic profiling showed L-asparaginase hypersensitivity in the siTop1 cells. Resistance to camptothecin, indenoisoquinoline, aphidicolin, hydroxyurea, and staurosporine and hypersensitivity to etoposide and actinomycin D show that Top1, in addition to being the target of camptothecins, also regulates DNA replication, rDNA stability, and apoptosis. Overall, our studies show the pleiotropic nature of human Top1 activities. In addition to its classic DNA nicking-closing functions, Top1 plays critical nonclassic roles in genomic stability, gene-specific transcription, and response to various anticancer agents. The reported cell lines and approaches described in this article provide new tools to perform detailed functional analyses related to Top1 function.

A novel polypyrimidine antitumor agent FdUMP[10] induces thymineless death with topoisomerase I-DNA complexes.

FdUMP[10], a 10mer of 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP), the thymidylate synthase inhibitory metabolite of 5-fluorouracil (FU), is most closely correlated with the DNA topoisomerase I (Top1) inhibitor camptothecin in the National Cancer Institute COMPARE analysis, but not with FU. FdUMP[10] exhibits more potent antiproliferative activity than FdUMP or 5-fluoro-2'-deoxyuridine (FdU) and is markedly more active than FU. Camptothecin-resistant P388/CPT45 cells lacking Top1 are cross-resistant to FdUMP[10] as well as to FdUMP, FdU, and the thymidylate synthase inhibitor raltitrexed (Tomudex). FdUMP[10] induces DNA single-strand breaks and cellular Top1-DNA complexes. Such complexes are also observed in response to FdUMP, FdU, raltitrexed, and FU. The FdUMP[10]-induced Top1-DNA complexes are not inhibited by the caspase inhibitor z-VAD-fmk and form independently of apoptotic DNA fragmentation, indicating that they do not correspond to apoptotic Top1-DNA complexes. In biochemical assay, Top1 is directly trapped at uracil and FdU misincorporation sites. We propose that FdUMP[10] damages DNA by trapping Top1 at uracil and FdU misincorporation sites resulting from thymidylate synthase inhibition and thymine depletion.

DNA-protein cross-links and replication-dependent histone H2AX phosphorylation induced by aminoflavone (NSC 686288), a novel anticancer agent active against human breast cancer cells.

Aminoflavone (5-amino-2,3-fluorophenyl)-6,8-difluoro-7-methyl-4H-1-benzopyran-4-one) (NSC 686288) is a candidate for possible advancement to phase I clinical trial. Aminoflavone has a unique activity profile in the NCI 60 cell lines (COMPARE analysis; http://www.dtp.nci.nih.gov/docs/dtp_search.html), and exhibits potent cellular and animal antitumor activity. To elucidate the mechanism of action of aminoflavone, we studied DNA damage in MCF-7 cells. Aminoflavone induced DNA-protein cross-links (DPC) and DNA single-strand breaks (SSB). Aminoflavone induced high levels of DPC and much lower level of SSB than camptothecin, which induces equal levels of DPC and SSB due to the trapping topoisomerase I-DNA complexes. Accordingly, neither topoisomerase I nor topoisomerase II were detectable in the aminoflavone-induced DPC. Aminoflavone also induced dose- and time-dependent histone H2AX phosphorylation (gamma-H2AX). Gamma-H2AX foci occurred with DPC formation, and like DPC, persisted after aminoflavone removal. Aphidicolin prevented gamma-H2AX formation, suggesting that gamma-H2AX foci correspond to replication-associated DNA double-strand breaks. Accordingly, no gamma-H2AX foci were found in proliferating cell nuclear antigen-negative or in mitotic cells. Bromodeoxyuridine incorporation and fluorescence-activated cell sorting analyses showed DNA synthesis inhibition uniformly throughout the S phase after exposure to aminoflavone. Aminoflavone also induced RPA2 and p53 phosphorylation, and induced p21(Waf1/Cip1) and MDM2, demonstrating S-phase checkpoint activation. These studies suggest that aminoflavone produces replication-dependent DNA lesions and S-phase checkpoint activation following DPC formation. Gamma-H2AX may be a useful clinical marker for monitoring the efficacy of aminoflavone in tumor therapies.

Association of XRCC1 and tyrosyl DNA phosphodiesterase (Tdp1) for the repair of topoisomerase I-mediated DNA lesions.

DNA topoisomerase I (Top1) is converted into a cellular poison by camptothecin (CPT) and various endogenous and exogenous DNA lesions. In this study, we used X-ray repair complementation group 1 (XRCC1)-deficient and XRCC1-complemented EM9 cells to investigate the mechanism by which XRCC1 affects the cellular responses to Top1 cleavage complexes induced by CPT. XRCC1 complementation enhanced survival to CPT-induced DNA lesions produced independently of DNA replication. CPT-induced comparable levels of Top1 cleavage complexes (single-strand break (SSB) and DNA-protein cross-links (DPC)) in both XRCC1-deficient and XRCC1-complemented cells. However, XRCC1-complemented cells repaired Top1-induced DNA breaks faster than XRCC1-deficient cells, and exhibited enhanced tyrosyl DNA phosphodiesterase (Tdp1) and polynucleotide kinase phosphatase (PNKP) activities. XRCC1 immunoprecipitates contained Tdp1 polypeptide, and both Tdp1 and PNKP activities, indicating a functional connection between the XRCC1 single-strand break repair pathway and the repair of Top1 covalent complexes by Tdp1 and PNKP.

[Specific antibodies against the nucleocapsid protein and S1 domain of spike glycoprotein in patients with severe acute respiratory syndrome].

OBJECTIVE: To explore the laws of the appearance of the specific serum antibodies against the nucleocapsid (N) protein and the S1 domain of spike (S) glycoprotein in patients with severe acute respiratory syndrome (SARS) and to evaluate the value of these two proteins to be used as diagnostic makers for SARS. METHODS: The serum samples of 86 patients with SARS confirmed clinically and serologically, 31 males and 55 females, aged 9 approximately 86, with the course of disease of 1 approximately 81 days, and 745 healthy persons were collected during the course. The specific immunoglobulin G (IgG) against N protein, IgG against S1 domain of S protein, and the SARS-CoV IgG in these sera were detected by ELISA. RESULTS: The positive rates of anti-N-IgG, anti S1-IgG, and anti-SARS-CoV IgG were 14% (6/44), 5% (2/44), and 14% (6/44) respectively in the first week of the course of disease, 56% (10/18), 39% (7/18), and 56% (10/18) respectively in the second week, and 100% (24/24), S1-IgG 83% (20/24), and 100% (24/24) respectively in the third week. The agreement rates of the results of anti-N-IgG and anti-s1-IgG with that of the anti-SARS-CoV IgG were 88% (76/86) and 83% (71/86) respectively. The anti-SARS-CoV IgG positive rate in the healthy persons was 1.88% (14.745). CONCLUSION: The N protein and S1 protein may be used as antigens in the development of serological assay for detection of SARS-CoV infection.

Non-camptothecin DNA topoisomerase I inhibitors in cancer therapy.

Human DNA topoisomerase I is the target of camptothecins, which have been recently introduced in the clinic for cancer chemotherapy. The discovery of novel non-camptothecin inhibitors is facilitated by the availability of biochemical and cellular assays for testing topoisomerase I activity. Among the non-camptothecin inhibitors, the indolocarbazoles (NB-506 and J-107088) are the most advanced in their development, and are in clinical trials. A number of indenoisoquinolines and minor groove binders (benzimidazoles) have been reported recently. Their antitumor activity is promising for further development. The potential binding site(s) of topoisomerase I inhibitors in the enzyme I-DNA complex is discussed.

Functional expression of guinea pig growth hormone receptor and its mutants in mammalian cells.

The cDNA of guinea pig (Cavia porcellus) growth hormone receptor (gpGHR) was cloned using RT-PCR in our laboratory. By sequence alignment, substitutions of amino acids conserved in other mammalian GHRs were found. For example, histidine-168 and tyrosine-332 equivalent to positions 170 and 333 in other mammalian GHRs, which were considered to be necessary for the dimerization of GHR and the specific GH-stimulated functions respectively, were replaced by tyrosine and serine in gpGHR. Here, we report the functional expression of gpGHR and its mutants, gpGHRY168H and gpGHRS332Y, in COS-7 cells and/or Chinese hamster ovary (CHO) cells. It was shown that the COS-7 cells transfected with pcDNA3-gpGHR possessed high affinity to bovine GH [K(a) = 1.3 x10(9) (mol/L)(-1)] and a protein band with molecular weight around 92 kD was detected by anti-mouse GHR monoclonal antibody (mAb263). When CHO cells were transfected with the expression vectors, pcDNA3-gpGHR, pcDNA3-gpGHRY168H and pcDNA3-gpGHRS332Y, the gpGHR and its mutants were expressed and the ligand binding, phosphorylation of JAK2, protein synthesis, and lipogenesis were studied. It was found that the mutation of serine to tyrosine at position 332 greatly increased the GH-stimulated protein synthesis and the phosphorylation of JAK2, while the mutation of tyrosine to histidine at position 168 increased the protein synthesis and decreased the phosphorylation of JAK2 only weakly. However, both mutations decreased the GH-stimulated lipogenesis. Thus, our study provides the experimental evidence that gpGHR may mediate the metabolic actions of GH and the substitutions of some conserved amino acids in gpGHR result in the changes of post-binding signaling.

[Identification of interaction and interaction domains between neuroglobin and Na(+), K(+)-ATPase beta2 subunit].

The pre-transformed human fetal brain cDNA library was used to screen the protein interacting with neuroglobin by using yeast two hybrid system III from ClonTech Inc. The protein encoded by one of the clones interacting with neuroglobin (NGB) was confirmed to be the C terminus of the Na(+), K(+)-ATPase beta2 subunit (NKA1b2) based on amino acid sequences. Then the full-length coding region cDNA sequence of NKA1b2 was obtained from human fetal brain cDNA library by PCR. A set of experiments were designed to test the interaction between NGB and NKA1b2. Interaction between NGB and NKA1b2 was confirmed by binding assay in vitro. Furthermore, the interaction was also proved by co-immunoprecipitation test in vivo. Moreover, the structure integrity of neuroglobin was found to be essential for the interaction between NGB and NKA1b2 by yeast two hybrid method with a series of neuroglobin truncated mutants.

Preparation and characterization of monoclonal antibodies against S1 domain at N-terminal residues 249 to 667 of SARS-associated coronavirus S1 protein.

OBJECTIVE: To prepare and characterize monoclonal antibodies (mAbs) against S1 protein of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV). METHODS: 6-His-tagged recombinant fragment at N-terminal residues 249 to 667 of SARS-CoV S1 protein including S-protein receptor-binding domain was expressed in E.coli. The immunogenicity of this S1 domain was identified and used to immunize BALB/c mice for the production of hybridomas. The identification of the mAbs against this S1 domain was performed using indirect enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA) and Western blotting, respectively. RESULTS: Three hybridomas producing mAbs specific to the S1 domain was obtained, with a relative molecular mass of 48,500. None of the 3 mAbs were reactive with human coronaviruses 229E and OC43. Two of the mAbs were IgG2a isotype, and the other was IgG1. CONCLUSIONS: This is the first report of mAbs produced against S-protein receptor-binding domain of SARS-CoV. The 3 S1-specific mAbs may be useful for further study of the function of the S protein and for diagnosis of SARS-CoV infection.

Rapid and efficient preparation of monoclonal antibodies against SARS-associated coronavirus nucleocapsid protein by immunizing mice.

OBJECTIVE: To develop a rapid and efficient method for preparing monoclonal antibodies (mAb) against SARS-associated coronavirus (SARS-Cov) nucleocapsid (N) protein. METHODS: BALB/c mice were injected with the recombinant N protein of SARS-Cov into the foot-pads for the immunization, and the popliteal lymph nodes were isolated 15 d later for mAb-producing hybridomas, from which the mAbs against the N protein of SARS-Cov were screened. The identification of the mAb against the N protein of SARS-Cov was performed using indirect enzyme-linked immunosorbent assay (ELISA), indirect fluorescent-antibody assay (IFA), and Western immunoblotting. RESULTS: Four strains of hybridomas were obtained that produced the mAb specific to the N protein without detectable cross-reactivity with other pathogens. Of the 4 strains, 2 were identified as the immunoglobulin G1 (IgG1) isotype, 1 IgG2a, and the other IgG2b, with affinity constants (Ka) of 2 of the strains being 4.14 x 10(-9)M and 3.19 x 10(-9)M respectively. CONCLUSION: This is the first report on the preparation of mAb that is specific to the SARS-Cov, and the high-specificity and high-affinity mAb produced by the 4 strains of hybridomas provide a basis for further researches on the pathogenesis and early diagnosis of SARS.

[Antibody response of patients with severe acute respiratory syndrome (SARS) to nucleocapsid antigen of SARS-associated coronavirus].

OBJECTIVE: To assess serum antibody responses of patients with severe acute respiratory syndrome (SARS) to nucleocapsid (N) antigen of SARS-associated coronavirus. METHODS: The serum levels of IgM and IgG antibodies to N antigen were measured in 200 healthy blood donors and 13 SARS patients at different time points of acute and convalescent phases using indirect enzyme-linked immunosorbent assay (ELISA) with N fusion proteins of SARS-associated coronaviruses. RESULTS: The IgM positive critical value of 0.233 and IgG of 0.239 were selected as the threshold value for positive results that equals the product of 2.1 and the mean IgM and IgG levels of 200 healthy blood donors. In 13 patients with SARS, the antibody responses to N antigen were not detectable in the first week after the onset of symptoms. The IgM and IgG seroprotection rates were 83.3% and 66.7% respectively in the second week, both reaching 100% at the third week. IgM seroprotection rates was 61.5% in the second month, and 38.5% at third month. The IgG peaked one month after the onset and remained at high levels in the following 2 months. CONCLUSION: The antibody responses suggest that N protein of SARS is immunodominant and plays an important role in viral pathogenesis. This ELISA-based test for detecting anti- N antigen may be of significant value for SARS diagnosis.

Differences in competitive ability between plants from nonnative and native populations of a tropical invader relates to adaptive responses in abiotic and biotic environments.

The evolution of competitive ability of invasive plant species is generally studied in the context of adaptive responses to novel biotic environments (enemy release) in introduced ranges. However, invasive plants may also respond to novel abiotic environments. Here we studied differences in competitive ability between Chromolaena odorata plants of populations from nonnative versus native ranges, considering biogeographical differences in both biotic and abiotic environments. An intraspecific competition experiment was conducted at two nutrient levels in a common garden. In both low and high nutrient treatments, C. odorata plants from nonnative ranges showed consistently lower root to shoot ratios than did plants from native ranges grown in both monoculture and competition. In the low nutrient treatment, C. odorata plants from nonnative ranges showed significantly lower competitive ability (competition-driven decreases in plant height and biomass were more), which was associated with their lower root to shoot ratios and higher total leaf phenolic content (defense trait). In the high nutrient treatment, C. odorata plants from nonnative ranges showed lower leaf toughness and cellulosic contents (defense traits) but similar competitive ability compared with plants from native ranges, which was also associated with their lower root to shoot ratios. Our results indicate that genetically based shifts in biomass allocation (responses to abiotic environments) also influence competitive abilities of invasive plants, and provide a first potential mechanism for the interaction between range and environment (environment-dependent difference between ranges).