@article{xu_zhang_zhu_xiao_zhu_zhang_yu_li_zhu_tu_et al._2020, title={Large losses of ammonium-nitrogen from a rice ecosystem under elevated CO2}, volume={6}, ISSN={["2375-2548"]}, DOI={10.1126/sciadv.abb7433}, abstractNote={Carbon dioxide enrichment facilitates nitrogen loss through anaerobic oxidation of ammonium coupled to the reduction of iron.}, number={42}, journal={SCIENCE ADVANCES}, author={Xu, Chenchao and Zhang, Kaihang and Zhu, Wanying and Xiao, Jing and Zhu, Chen and Zhang, Naifang and Yu, Fangjian and Li, Shuyao and Zhu, Chunwu and Tu, Qichao and et al.}, year={2020}, month={Oct} }
 @article{patil_lee_macias_lam_xu_jones_ho_rodriguez-puebla_chen_2009, title={Robe of Cyclin D1 as a Mediator of c-Met- and beta-Catenin-Induced Hepatocarcinogenesis}, volume={69}, ISSN={["1538-7445"]}, DOI={10.1158/0008-5472.CAN-08-2514}, abstractNote={Abstract
               Activation of c-Met signaling and β-catenin mutations are frequent genetic events observed in liver cancer development. Recently, we demonstrated that activated β-catenin can cooperate with c-Met to induce liver cancer formation in a mouse model. Cyclin D1 (CCND1) is an important cell cycle regulator that is considered to be a downstream target of β-catenin. To determine the importance of CCND1 as a mediator of c-Met– and β-catenin–induced hepatocarcinogenesis, we investigated the genetic interactions between CCND1, β-catenin, and c-Met in liver cancer development using mouse models. We coexpressed CCND1 with c-Met in mice and found CCND1 to cooperate with c-Met to promote liver cancer formation. Tumors induced by CCND1/c-Met had a longer latency period, formed at a lower frequency, and seemed to be more benign compared with those induced by β-catenin/c-Met. In addition, when activated β-catenin and c-Met were coinjected into CCND1-null mice, liver tumors developed despite the absence of CCND1. Intriguingly, we observed a moderate accelerated tumor growth and increased tumor malignancy in these CCND1-null mice. Molecular analysis showed an up-regulation of cyclin D2 (CCND2) expression in CCND1-null tumor samples, indicating that CCND2 may replace CCND1 in hepatic tumorigenesis. Together, our results suggest that CCND1 functions as a mediator of β-catenin during HCC pathogenesis, although other molecules may be required to fully propagate β-catenin signaling. Moreover, our data suggest that CCND1 expression is not essential for liver tumor development induced by c-Met and β-catenin. [Cancer Res 2009;69(1):253–61]}, number={1}, journal={CANCER RESEARCH}, author={Patil, Mohini A. and Lee, Susie A. and Macias, Everardo and Lam, Ernest T. and Xu, Chuanrui and Jones, Kirk D. and Ho, Coral and Rodriguez-Puebla, Marcelo and Chen, Xin}, year={2009}, month={Jan}, pages={253–261} }
 @article{chen_tu_burton_watson_burkey_hu_2007, title={Plant nitrogen acquisition and interactions under elevated carbon dioxide: impact of endophytes and mycorrhizae}, volume={13}, ISSN={["1365-2486"]}, DOI={10.1111/j.1365-2486.2007.01347.x}, abstractNote={AbstractBoth endophytic and mycorrhizal fungi interact with plants to form symbiosis in which the fungal partners rely on, and sometimes compete for, carbon (C) sources from their hosts. Changes in photosynthesis in host plants caused by atmospheric carbon dioxide (CO2) enrichment may, therefore, influence those mutualistic interactions, potentially modifying plant nutrient acquisition and interactions with other coexisting plant species. However, few studies have so far examined the interactive controls of endophytes and mycorrhizae over plant responses to atmospheric CO2enrichment. UsingFestuca arundinaceaSchreb andPlantago lanceolataL. as model plants, we examined the effects of elevated CO2on mycorrhizae and endophyte (Neotyphodium coenophialum)and plant nitrogen (N) acquisition in two microcosm experiments, and determined whether and how mycorrhizae and endophytes mediate interactions between their host plant species. Endophyte‐free and endophyte‐infectedF. arundinaceavarieties,P. lanceolataL., and their combination with or without mycorrhizal inocula were grown under ambient (400 μmol mol−1) and elevated CO2(ambient + 330 μmol mol−1). A15N isotope tracer was used to quantify the mycorrhiza‐mediated plant acquisition of N from soil. Elevated CO2stimulated the growth ofP. lanceolatagreater thanF. arundinacea, increasing the shoot biomass ratio ofP. lanceolatatoF. arundinaceain all the mixtures. Elevated CO2also increased mycorrhizal root colonization ofP. lanceolata, but had no impact on that ofF. arundinacea. Mycorrhizae increased the shoot biomass ratio ofP. lanceolatatoF. arundinaceaunder elevated CO2. In the absence of endophytes, both elevated CO2and mycorrhizae enhanced15N and total N uptake ofP. lanceolatabut had either no or even negative effects on N acquisition ofF. arundinacea, altering N distribution between these two species in the mixture. The presence of endophytes inF. arundinacea, however, reduced the CO2effect on N acquisition inP. lanceolata, although it did not affect growth responses of their host plants to elevated CO2. These results suggest that mycorrhizal fungi and endophytes might interactively affect the responses of their host plants and their coexisting species to elevated CO2.}, number={6}, journal={GLOBAL CHANGE BIOLOGY}, author={Chen, Xin and Tu, Cong and Burton, Michael G. and Watson, Dorothy M. and Burkey, Kent O. and Hu, Shuijin}, year={2007}, month={Jun}, pages={1238–1249} }
 @article{tu_booker_watson_chen_rufty_shi_hu_2006, title={Mycorrhizal mediation of plant N acquisition and residue decomposition: Impact of mineral N inputs}, volume={12}, ISSN={["1365-2486"]}, DOI={10.1111/j.1365-2486.2006.01149.x}, abstractNote={AbstractMycorrhizas are ubiquitous plant–fungus mutualists in terrestrial ecosystems and play important roles in plant resource capture and nutrient cycling. Sporadic evidence suggests that anthropogenic nitrogen (N) input may impact the development and the functioning of arbuscular mycorrhizal (AM) fungi, potentially altering host plant growth and soil carbon (C) dynamics. In this study, we examined how mineral N inputs affected mycorrhizal mediation of plant N acquisition and residue decomposition in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that either prevented or allowed AM fungal hyphae but not plant roots to grow into the TEST compartments. Wild oat (Avena fatua L.) was planted in the HOST compartments that had been inoculated with either a single species of AM fungus, Glomus etunicatum, or a mixture of AM fungi including G. etunicatum. Mycorrhizal contributions to plant N acquisition and residue decomposition were directly assessed by introducing a mineral 15N tracer and 13C‐rich residues of a C4 plant to the TEST compartments. Results from 15N tracer measurements showed that AM fungal hyphae directly transported N from the TEST soil to the host plant. Compared with the control with no penetration of AM fungal hyphae, AM hyphal penetration led to a 125% increase in biomass 15N of host plants and a 20% reduction in extractable inorganic N in the TEST soil. Mineral N inputs to the HOST compartments (equivalent to 5.0 g N m−2 yr−1) increased oat biomass and total root length colonized by mycorrhizal fungi by 189% and 285%, respectively, as compared with the no‐N control. Mineral N inputs to the HOST plants also reduced extractable inorganic N and particulate residue C proportion by 58% and 12%, respectively, in the corresponding TEST soils as compared to the no‐N control, by stimulating AM fungal growth and activities. The species mixture of mycorrhizal fungi was more effective in facilitating N transport and residue decomposition than the single AM species. These findings indicate that low‐level mineral N inputs may significantly enhance nutrient cycling and plant resource capture in terrestrial ecosystems via stimulation of root growth, mycorrhizal functioning, and residue decomposition. The long‐term effects of these observed alterations on soil C dynamics remain to be investigated.}, number={5}, journal={GLOBAL CHANGE BIOLOGY}, author={Tu, C and Booker, FL and Watson, DM and Chen, X and Rufty, TW and Shi, W and Hu, SJ}, year={2006}, month={May}, pages={793–803} }
 @article{hu_tu_chen_gruver_2006, title={Progressive N limitation of plant response to elevated CO2: a microbiological perspective}, volume={289}, ISSN={["0032-079X"]}, DOI={10.1007/s11104-006-9093-4}, number={1-2}, journal={PLANT AND SOIL}, author={Hu, Shuijin and Tu, Cong and Chen, Xin and Gruver, Joel B.}, year={2006}, month={Nov}, pages={47–58} }
 @article{wu_chen_tang_2005, title={Lead accumulation in weed communities with various species}, volume={36}, ISSN={["1532-2416"]}, DOI={10.1081/CSS-200062486}, abstractNote={Abstract The use of weeds to eliminate pollutants from agroecosystem has been considered recently. This study examined the ability of 17 weed species and 5 weed species combinations to accumulate lead (Pb) in polluted soil in greenhouse. The biomass production of all weed species used in this experiment was not affected by Pb in the polluted soil (334±22 Pb mg/kg soil) compared with growth in unpolluted soil (23±1 mg Pb/kg soil). Lead was accumulated mainly in roots of most weed species except Kummerowia striata, Ixeris chinensis, Digitaria ciliaris, Echinochloa crugalli var. mitis that largely accumulated Pb in their shoots. Total Pb accumulation of weed communities with four or six species were higher than that with two or eight species. Total Pb accumulation increased with enhancing biomass of weed communities.}, number={13-14}, journal={COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS}, author={Wu, CH and Chen, X and Tang, JJ}, year={2005}, pages={1891–1902} }