title: Clonal integration ameliorates the carbon accumulation capacity of a stoloniferous herb, Glechoma longituba, growing in heterogenous light conditions by facilitating nitrogen assimilation in the rhizosphere.
abstract: OBJECTIVE
  Enhanced availability of photosynthates increases nitrogen (N) mineralization and nitrification in the rhizosphere via rhizodeposition from plant roots. Under heterogeneous light conditions, photosynthates supplied by exposed ramets may promote N assimilation in the rhizosphere of shaded, connected ramets. This study was conducted to test this hypothesis.
  
  
  METHODS
  Clonal fragments of the stoloniferous herb Glechoma longituba with two successive ramets were selected. Mother ramets were subjected to full sunlight and offspring ramets were subjected to 80 % shading, and the stolon between the two successive ramets was either severed or left intact. Measurements were taken of photosynthetic and growth parameters. The turnover of available soil N was determined together with the compostion of the rhizosphere microbial community.
  
  
  RESULTS
  The microbial community composition in the rhizosphere of shaded offspring ramets was significantly altered by clonal integration. Positive effects of clonal integration were observed on NAGase activity, net soil N mineralization rate and net soil N nitrification rate. Increased leaf N and chlorophyll content as well as leaf N allocation to the photosynthetic machinery improved the photosynthetic capability of shaded offspring ramets when the stolon was left intact. Clonal integration improved the growth performance of shaded, connected offspring ramets and whole clonal fragments without any cost to the exposed mother ramets.
  
  
  CONCLUSIONS
  Considerable differences in microbial community composition caused by clonal integration may facilitate N assimilation in the rhizosphere of shaded offspring ramets. Increased N content in the photosynthetic machinery may allow pre-acclimation to high light conditions for shaded offspring ramets, thus promoting opportunistic light capture. In accordance with the theory of the division of labour, it is suggested that clonal integration may ameliorate the carbon assimilation capacity of clonal plants, thus improving their fitness in temporally and spatially heterogeneous habitats.
authors.affiliation: College of Life Science, Sichuan Normal University, Chengdu 610101, China and College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China cjs74@163.com leiningfei@cdut.cn.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Chen
authors.affiliation: College of Life Science, Sichuan Normal University, Chengdu 610101, China and College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Life Science, Sichuan Normal University, Chengdu 610101, China and College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Life Science, Sichuan Normal University, Chengdu 610101, China and College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zong
authors.affiliation: College of Life Science, Sichuan Normal University, Chengdu 610101, China and College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China cjs74@163.com leiningfei@cdut.cn.
authors.forename: Ning-Fei
authors.initials: NF
authors.lastname: Lei
mesh_terms: D002244:Carbon / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D019686:Lamiaceae / Q000235:genetics / Q000378:metabolism*; D008027:Light; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D058441:Rhizosphere; D012988:Soil Microbiology
chemical_list: D002734:Chlorophyll; D002244:Carbon; D009584:Nitrogen
keywords: Clonal plants; Glechoma longituba; Lamiaceae; clonal integration; microbial community composition; mineralization; nitrification; nitrogen allocation; nutrition; photosynthesis; rhizosphere