Marques et al. 2021 (Article) Brazil

Does seasonal drought affect C3 and CAM tank-bromeliads from Campo Rupestre differently?

Author(s):—Alexandre Aparecido Duarte Andréa Rodrigues Marques & José Piresde Lemos-Filho

Publication:—Flora 282(online): 1-10. (2021) — DOI

Abstract:—The Campo Rupestre (CR) harbors a diversified flora including both C3 and CAM tank-bromeliads growing side by side. This scenario facilitates the investigation of whether different species of tank-bromeliads possess convergent physiological responses to drought with regard to their different water-use strategies. To determine the drought response of tank-bromeliads we evaluated seasonal variation in titratable acidity, stomatal conductance (gs), chlorophyll fluorescence, leaf water content (LWC), and pigment content of the CAM species Aechmea nudicaulis and Neoregelia bahiana and the C3 species Vriesea minarum. A decrease in gs was observed in the dry season for plants of both types of photosynthetic pathways, which accompanied a reduction in LWC and a decrease in tissue acidity for the CAM species. Vriesea minarum presented a thinner hydrenchyma and stronger stomatal restriction in the dry season compared to the CAM species. Irrespective of photosynthetic pathway, drought led to a decrease in total chlorophyll and the Chla:Chlb ratio and an increase in carotenoid content, but these changes were not sufficient to prevent photoinhibition. These results indicate that water and light stress during the dry season promoted a convergence of responses in gas-exchange and PSII damage in the studied co-occurring C3 and CAM tank-bromeliads of CR.

Keywords:—Chlorophyll fluorescenceHydrenchymaLeaf anatomyLeaf water statusPhoto-inhibitionWater use strategy