Response of Plants to Water Stress: A Meta-Analysis

Abstract

Plants are key to the functionality of many ecosystem processes. The duration and intensity of water stress are anticipated to increase in the future; however, a detailed elucidation of the responses of plants to water stress remains incomplete. For this study, we present a meta-analysis derived from the 1,301 paired observations of 84 studies to evaluate the responses of plants to water stress. The results revealed that although water stress inhibited plant growth and photosynthesis, it increased reactive oxygen species (ROS), plasma membrane permeability, enzymatic antioxidants, and non-enzymatic antioxidants. Importantly, these responses generally increased with the intensity and duration of water stress, with a more pronounced decrease in ROS anticipated over time. Our findings suggested that the overproduction of ROS was the primary mechanism behind the responses of plants to water stress, where plants appeared to acclimatize to water stress, to some extent, over time. Our synthesis provides a framework for better understanding the responses and mechanisms of plants under drought conditions.

Keywords: drought adaption; meta-analysis; plants; reactive oxygen species; water stress.

Figure 1

Response of physiological indices to water stress. Values are the means and 95% confidence intervals. The dashed black line represents zero effect size. Numbers without and within parentheses represent the number of observations and studies, respectively. Chl, Fv/Fm, qP, ROS, MDA, EL, APX, GR, CAT, POD, SOD, ABA, AsA, and Car, represent chlorophyll, maximal efficiency of PSII photochemistry, photochemical quenching coefficient, reactive oxygen species, malondialdehyde, electrolyte leakage, ascorbate peroxidase, glutathione reductase, catalase, peroxidase, superoxide dismutase, abscisic acid, ascorbate, and carotenoid, respectively.

Figure 2

Response of plant performance (A) and tissues (B) to water stress. Values are means and 95% confidence intervals. Dashed black line represents zero effect size. Numbers without and within parentheses represent the number of observations and studies, respectively. PS, PMP, EA, and NEA represent photosynthesis, plasma membrane permeability, enzymatic antioxidants, and non-enzymatic antioxidants, respectively.

Figure 3

Responses of plant physiological indices to water stress intensity. Linear regressions (blue lines) and their 95% confidence intervals (shaded areas) and corresponding levels of significances (P values) are presented. Circle sizes are proportional to the sampling variances. See Figure 1 for abbreviations.

Figure 4

Responses of plant physiological indices to experimental duration. Linear regressions (blue lines) and their 95% confidence intervals (shaded areas) and corresponding levels of significances (P values) are presented. Circle sizes are proportional to the sampling variances. See Figure 1 for abbreviations.

Figure 5

Responses of plant performances to water stress intensity. Linear regressions (blue lines) and their 95% confidence intervals (shaded areas) and corresponding levels of significances (P values) are presented. Circle sizes are proportional to the sampling variances. See Figure 2 for abbreviations.

Figure 6

Responses of plant performances to experimental duration. Linear regressions (blue lines) and their 95% confidence intervals (shaded areas) and corresponding levels of significances (P values) are presented. Circle sizes are proportional to the sampling variances. See Figure 2 for abbreviations.