TY - JOUR
T1 - Slowly developing drought stress increases photosynthetic acclimation of Catharanthus roseus
AU - Kim, Jongyun
AU - van Iersel, Marc W.
PY - 2011/10
Y1 - 2011/10
N2 - Our understanding of plant responses to drought has improved over the decades. However, the importance of the rate of drought imposition on the response is still poorly understood. To test the importance of the rate at which drought stress develops, whole-plant photosynthesis (P net), respiration (R dark), daily carbon gain (DCG), daily evapotranspiration (DET) and water use efficiency (WUE) of vinca (Catharanthus roseus), subjected to different drought imposition rates, were investigated. We controlled the rate at which the substrate dried out with an automated irrigation system that allowed pot weight to decrease gradually throughout the drying period. Fast, intermediate and slow drying treatments reached their final pot weight [500 g, substrate water content (θ) ≈ 0.10 m 3 m -3] after 3.1, 6.6 and 10 days, respectively. Although all drying treatments decreased P net and R dark, slow drying reduced P net and R dark less than fast drying. At a θ < 0.10 m 3 m -3, DCG and DET in the slow drying treatment were reduced by ≈50%, whereas DCG and DET in the fast drying treatment were reduced by 85 and 70% at a θ of 0.16 m 3 m -3. Plants exposed to slow drought imposition maintained a high WUE, even at θ < 0.10 m 3 m -3. Overall, physiological responses to low θ were less severe in plants subjected to slow drying as compared with fast drying, even though the final θ was lower for plants exposed to slow drying. This suggests that the rate at which drought stress develops has important implications for the level of acclimation that occurs.
AB - Our understanding of plant responses to drought has improved over the decades. However, the importance of the rate of drought imposition on the response is still poorly understood. To test the importance of the rate at which drought stress develops, whole-plant photosynthesis (P net), respiration (R dark), daily carbon gain (DCG), daily evapotranspiration (DET) and water use efficiency (WUE) of vinca (Catharanthus roseus), subjected to different drought imposition rates, were investigated. We controlled the rate at which the substrate dried out with an automated irrigation system that allowed pot weight to decrease gradually throughout the drying period. Fast, intermediate and slow drying treatments reached their final pot weight [500 g, substrate water content (θ) ≈ 0.10 m 3 m -3] after 3.1, 6.6 and 10 days, respectively. Although all drying treatments decreased P net and R dark, slow drying reduced P net and R dark less than fast drying. At a θ < 0.10 m 3 m -3, DCG and DET in the slow drying treatment were reduced by ≈50%, whereas DCG and DET in the fast drying treatment were reduced by 85 and 70% at a θ of 0.16 m 3 m -3. Plants exposed to slow drought imposition maintained a high WUE, even at θ < 0.10 m 3 m -3. Overall, physiological responses to low θ were less severe in plants subjected to slow drying as compared with fast drying, even though the final θ was lower for plants exposed to slow drying. This suggests that the rate at which drought stress develops has important implications for the level of acclimation that occurs.
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U2 - 10.1111/j.1399-3054.2011.01493.x
DO - 10.1111/j.1399-3054.2011.01493.x
M3 - Article
C2 - 21645003
AN - SCOPUS:80052551867
VL - 143
SP - 166
EP - 177
JO - Physiologia Plantarum
JF - Physiologia Plantarum
SN - 0031-9317
IS - 2
ER -