Effects of fully open-air [CO2] elevation on leaf photosynthesis and ultrastructure of Isatis indigotica fort.
Traditional Chinese medicine relies heavily on herbs, yet there is no information on how these herb plants would respond to climate change. In order to gain insight into such response, we studied the effect of elevated [CO2] on Isatis indigotica Fort, one of the most popular Chinese herb plants. The changes in leaf photosynthesis, chlorophyll fluorescence, leaf ultrastructure and biomass yield in response to elevated [CO2] (550±19 µmol mol(-1)) were determined at the Free-Air Carbon dioxide Enrichment (FACE) experimental facility in North China. Photosynthetic ability of I. indigotica was improved under elevated [CO2]. Elevated [CO2] increased net photosynthetic rate (P N), water use efficiency (WUE) and maximum rate of electron transport (J max) of upper most fully-expended leaves, but not stomatal conductance (gs), transpiration ratio (Tr) and maximum velocity of carboxylation (V c,max). Elevated [CO2] significantly increased leaf intrinsic efficiency of PSII (Fv'/Fm') and quantum yield of PSII(ΦPS II ), but decreased leaf non-photochemical quenching (NPQ), and did not affect leaf proportion of open PSII reaction centers (qP) and maximum quantum efficiency of PSII (Fv/Fm). The structural chloroplast membrane, grana layer and stroma thylakoid membranes were intact under elevated [CO2], though more starch grains were accumulated within the chloroplasts than that of under ambient [CO2]. While the yield of I. indigotica was higher due to the improved photosynthesis under elevated [CO2], the content of adenosine, one of the functional ingredients in indigowoad root was not affected.
College of Agronomy, Shanxi Agricultural University, Taigu, China ; Key Laboratory of Ministry of Agriculture on Agro-environment and Climate Change, Institute of Environment and Sustainable Development in Agriculture (IEDA), Chinese Academy of Agricultural Sciences, Beijing, China ; Key Laboratory of Crop Gene Resources and Germplasm Enhancement on Loess Plateau, Ministry of Agriculture, Institute of Crop Genetic Resources, Shanxi Academy of Agricultural Sciences, Taiyuan, China.
Xingyu
X
Hao
Ping
P
Li
Yongxiang
Y
Feng
Xue
X
Han
Ji
J
Gao
Erda
E
Lin
Yuanhuai
Y
Han
D000241:Adenosine / Q000378:metabolism; D000388:Air; D018533:Biomass; D002245:Carbon Dioxide / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism; D005453:Fluorescence; D031219:Isatis / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D058503:Mesophyll Cells / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000166:cytology / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism
D002734:Chlorophyll; D002245:Carbon Dioxide; D000241:Adenosine