Does Low Stomatal Conductance or Photosynthetic Capacity Enhance Growth at Elevated CO2 in Arabidopsis?

作者：Easlon Hsien Ming^*; Carlisle Eli; McKay John K; Bloom Arnold J

来源：Plant Physiology, 2015, 167(3): 793-799.

DOI：10.1104/pp.114.245241

The objective of this study was to determine if low stomatal conductance (g) increases growth, nitrate (NO32-) assimilation, and nitrogen (N) utilization at elevated CO2 concentration. Four Arabidopsis (Arabidopsis thaliana) near isogenic lines (NILs) differing in g were grown at ambient and elevated CO2 concentration under low and high NO32- supply as the sole source of N. Although g varied by 32% among NILs at elevated CO2, leaf intercellular CO2 concentration varied by only 4% and genotype had no effect on shoot NO3- concentration in any treatment. Low-g NILs showed the greatest CO2 growth increase under N limitation but had the lowest CO2 growth enhancement under N-sufficient conditions. NILs with the highest and lowest g had similar rates of shoot NO3- assimilation following N deprivation at elevated CO2 concentration. After 5 d of N deprivation, the lowest g NIL had 27% lower maximum carboxylation rate and 23% lower photosynthetic electron transport compared with the highest g NIL. These results suggest that increased growth of low-g NILs under N limitation most likely resulted from more conservative N investment in photosynthetic biochemistry rather than from low g.

• 出版日期2015-3