Do morphological changes mediate plant responses to water stress? A steady-state experiment with two C<sub>4</sub> grasses

Title	Do morphological changes mediate plant responses to water stress? A steady-state experiment with two C₄ grasses
Publication Type	Journal Article
Year of Publication	2002
Authors	Fernández RJ, Wang M, Reynolds J.F
Journal	New Phytologist
Volume	155
Pagination	79-88
Date Published	2002
Call Number	00787
Keywords	article, articles, Bouteloua eriopoda, Bouteloua, drought, Bouteloua, growth analysis, Bouteloua, plasticity, Bouteloua, water use efficiency (WUE), drought tolerance, grass, drought, Bouteloua, drought, Eragrostis, Eragrostis lehmanniana, Eragrostis, drought, Eragrostis, growth analysis, Eragrostis, plasticity, Eragrostis, water use efficiency (WUE), journal, journals, plant, Bouteloua, plant, Eragrostis, water-use efficience, Bouteloua, water-use efficiency, Eragrostis
Abstract	It was hypothesized that plant growth reduction under water stress is caused primarily by a reduction of leaf-area ration (LAR, leaf area per unit of total plant dry mass). Two perennial Chihuahuan desert grass species (slow-growing Bouteloua eriopoda and fast-growing Eragrostis lehmanniana) were subjected over 6 weeks to a combination of two water-supply regimes (control and drought) and two levels of atmospheric CO₂ partial pressure (375 and 750 ìmol mol^-1). Drought reduced final biomass in Bouteloua by 60% regardless of CO₂ concentration. Eragrostis experienced a similar biomass reduction at 375 ìmol mol^-1, but large plants under elevated CO₂ attained growth rates comparable to those of controls. Overall, for plants of similar size, drought reduced LAR in both species much more strongly than it affected net assimilation rate. This reduction in LAR was caused by reductions in both specific leaf area and leaf weight ratio. We conclude that reduced growth under drought can be considered as a byproduct of the same plastic, developmental responses that result in a reduced water loss.
URL	http://www.newphytologist.com
Reprint Edition	In File (6/27/2002)