PT  - JOURNAL ARTICLE
AU  - Rengifo, E.
AU  - Urich, R.
AU  - Herrera, A.
TI  - Water Relations and Leaf Anatomy of the Tropical Species, Jatropha gossypifolia and Alternanthera crucis, Grown Under an Elevated CO<sub>2</sub> Concentration
DP  - 2002 Sep 1
TA  - Photosynthetica
PG  - 397--403
VI  - 40
IP  - 3
AID - 10.1023/A:1022679109425
IS  - 03003604
AB  - In order to address the question of how elevated CO<sub>2</sub> concentration (EC) will affect the water relations and leaf anatomy of tropical species, plants of Jatropha gossypifolia L. and Alternanthera crucis (Moq.) Bondingh were grown in five EC open top chambers (677 μmol mol<sup>-1</sup>) and five ambient CO<sub>2</sub> concentration (AC) open top chambers (454 μmol mol<sup>-1</sup>) with seasonal drought. No effect of EC was found on morning xylem water potential, leaf osmotic potential, and pressure potential of plants of J. gossypifolia. In A. crucis EC caused a significant increase in morning xylem water potential of watered plants, a decrease in osmotic potential, and an increase of 24-79 % in pressure potential of moderately droughted plants. This ameliorated the effects of drought. Stomatal characteristics of both leaf surfaces of J. gossypifolia and A. crucis showed time-dependent, but not [CO<sub>2</sub>]-dependent changes. In J. gossypifolia the thickness of whole leaf, palisade parenchyma, and spongy parenchyma, and the proportion of whole leaf thickness contributed by these parenchymata decreased significantly in response to EC. In A. crucis EC caused an increase in thickness of whole leaf, bundle sheath, and mesophyll, while the proportion of leaf cross-section comprised by the parenchymata remained unchanged. These effects disappeared with time under treatment, suggesting that acclimation of the leaf anatomy to the chambers and to EC took place in the successive flushes of leaves produced during the experiment.