Natural variation in stress response induced by low CO(2) in Arabidopsis thaliana

Variation in atmospheric carbon dioxide (CO(2)) concentration can dictate plant growth and development and shape plant evolution. For paired populations of 31 Arabidopsis accessions, respectively, grown under 100 or 380 ppm CO(2), we compared phenotypic traits related to vegetative growth and flowering time. Four accessions showed the least variation in measured growth traits between 100 ppm CO(2) and 380 ppm CO(2) conditions, though all accessions exhibited a dwarf stature with reduced biomass under low CO(2). Our comparison of accessions also incorporated the altitude (indicated in meters) above sea level at which they were originally collected. Notably, An-1 (50 m), Est (50 m), Ws-0 (150 m), and Ler-0 (600 m) showed the least differences (lower decrease or increase) between treatments in flowering time, rosette leaf number, specific leaf weight, stomatal density, and less negative δ(13)C values. When variations for all traits and seedset were considered together, Ws-0 exhibited the least change between treatments. Our results showed that physiological and phenotypic responses to low CO(2) varied among these accessions and did not correlate linearly with altitude, thus suggesting that slower growth or smaller stature under ambient CO(2) may potentially belie a fitness advantage for sustainable growth under low CO(2) availability.