title: [Effects of Ca2+ on photosynthetic parameters of Pinellia ternata and accumulations of active components in heat stress].
abstract: OBJECTIVE
  To study the effect of exogenous Ca2+ on photosynthetic parameters of Pinellia ternate and accumulations of active components under high temperature stress.
  
  
  METHODS
  The pigment contents of P. ternata leaves, photosynthesis parameters and chlorophyll fluorescence parameters of P. ternata leaves, the contents of guanosine, adenosine and polysaccharide in P. ternata tubers were measured based on different concentrations of exogenous Ca2+ in heat stress when the plant height of P. ternata was around 10 cm.
  
  
  RESULTS
  The contents of total chlorophyll and ratio of chlorophyll a/b were relatively higher by spaying Ca2+. Compared with the control, spaying 6 mmol x L(-1) Ca2+ significantly enhanced the net photosynthetic rate (Pn), transpiration (Tr) and stomatal limitation (L8), but reduced intercellular CO2 concentration (C) in P. ternata leaves. With the increase of Ca2+ concentration, maximal PS II efficiency (Fv/Fm), actual photosynthetic efficiency (Yield) and photochemical quenching coefficient (qP) initially increased and then decreased, however, minimal fluorescence (Fo) and non-photochemical quenching coefficient (NPQ) went down first and then went up. The contents of guanosine and polysaccharide and dry weight of P. ternata tubers showed a tendency of increase after decrease, and the content of adenosine increased with the increase of Ca2+ concentration. The content of guanosine and polysaccharide in P. ternata tubers and its dry weight reached maximum when spaying 6 mmol x L(-1) Ca2+.
  
  
  CONCLUSIONS
  With the treatment of calcium ion, the inhibition of photosynthesis and the damage of PS II system were relieved in heat stress, which increased the production of P. ternata tubers.
authors.forename: Wei-Xing
authors.initials: WX
authors.lastname: Yang
authors.forename: Gang-Gang
authors.initials: GG
authors.lastname: Hei
authors.forename: Jiao-Jiao
authors.initials: JJ
authors.lastname: Li
authors.forename: Hong-Min
authors.initials: HM
authors.lastname: Zhang
authors.forename: Lin-Lin
authors.initials: LL
authors.lastname: Li
authors.forename: Neng-Biao
authors.initials: NB
authors.lastname: Wu
mesh_terms: D001947:Breeding; D002118:Calcium / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D004305:Dose-Response Relationship, Drug; D018869:Heat-Shock Response / Q000187:drug effects*; D009929:Organ Size / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects*; D030021:Pinellia / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D002734:Chlorophyll; C037184:chlorophyll b; D002118:Calcium; D000077194:Chlorophyll A