Quantification of photosynthetic inorganic carbon utilisation via a bidirectional stable carbon isotope tracer  

作　　者：Hongtao Hang Yanyou WU 

机构地区：[1]State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry, Chinese Academy of Sciences,Guiyang 550081, China [2]University of Chinese Academy of Sciences, Beijing 100049,China

出　　处：《Acta Geochimica》2016年第2期130-147,共18页地球化学学报（英文）

基　　金：supported by the National Key Basic Research Program of China(2013CB956701);the National Natural Science Foundation of China (No.31070365);the project on social development of Guizhou Province (SY[2010]3043);the State Key Laboratory of Environmental Geochemistry (SKLEG2014909)

摘　　要：The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon （COe and HCO3-） by plants. The net photosynthetic COa assimilation （PN）, the photosynthetic assimilation of CO2 and bicarbonate （PN＇）, the proportion of increased leaf area （lEA） and the stable carbon isotope composition （δ13C） of Orychophragmus violaceus （Ov） and Brassica juncea （B j） under three bicarbonate levels （5, 10 and 15 mm NaHCO3） were examined to determine the relationship among PN, PN＇ and fLA. PN＇, not PN, changed synchronously with fLA. Moreover, the proportions of exogenous bicarbonate and total bicarbonate （including exogenous bicarbonate and dissolved CO2-generated bicarbonate） utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and 13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31% at 15 mm bicarbonate, respectively. Meanwhile, the propor- tions of exogenous bicarbonate and total bicarbonate uti- lised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate, 2.11% and 3.10 % at 10 mm bicarbonate, and 2.36 % and 3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants.The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods.Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon(CO_2and HCO_3^-) by plants. The net photosynthetic CO_2assimilation(PN), the photosynthetic assimilation of CO_2 and bicarbonate(PN'),the proportion of increased leaf area(fLA) and the stable carbon isotope composition(δ^(13)C) of Orychophragmus violaceus(Ov) and Brassica juncea(Bj)under three bicarbonate levels(5, 10 and 15 mm NaHCO_3)were examined to determine the relationship among PN,PN' and fLA. PN', not PN,changed synchronously with fLA.Moreover, the proportions of exogenous bicarbonate and total bicarbonate(including exogenous bicarbonate and dissolved CO_2-generated bicarbonate) utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31 % at15 mm bicarbonate, respectively. Meanwhile, the proportions of exogenous bicarbonate and total bicarbonate utilised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate,2.11 % and 3.10 % at 10 mm bicarbonate, and 2.36 % and3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO_2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants.

关 键 词：KARST Bicarbonate - Photosynthesis -Inorganic carbonic utilization Stable carbon isotopecomposition 

分 类 号：Q945.11[生物学—植物学]