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Are plant growth and photosynthesis limited by pre-drought following rewatering in grass?

Xu Z, Zhou G, Shimizu H - J. Exp. Bot. (2009)

Bottom Line: The results indicated that g(s) may be responsible for regulating actual photosynthetic efficiency.It is assumed that the new plant growth and photosynthetic potential enhanced by pre-drought following rewatering may try to overcompensate the great loss of the plant's net primary production due to the pre-drought effect.The present results highlight the episodic effects of drought on grass growth and photosynthesis.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Science, Beijing, PR China.

ABSTRACT
Although the relationship between grassland productivity and soil water status has been extensively researched, the responses of plant growth and photosynthetic physiological processes to long-term drought and rewatering are not fully understood. Here, the perennial grass (Leymus chinensis), predominantly distributed in the Euro-Asia steppe, was used as an experimental plant for an irrigation manipulation experiment involving five soil moisture levels [75-80, 60-75, 50-60, 35-50, and 25-35% of soil relative water content (SRWC), i.e. the ratio between present soil moisture and field capacity] to examine the effects of soil drought and rewatering on plant biomass, relative growth rate (RGR), and photosynthetic potential. The recovery of plant biomass following rewatering was lower for the plants that had experienced previous drought compared with the controls; the extent of recovery was proportional to the intensity of soil drought. However, the plant RGR, leaf photosynthesis, and light use potential were markedly stimulated by the previous drought, depending on drought intensity, whereas stomatal conductance (g(s)) achieved only partial recovery. The results indicated that g(s) may be responsible for regulating actual photosynthetic efficiency. It is assumed that the new plant growth and photosynthetic potential enhanced by pre-drought following rewatering may try to overcompensate the great loss of the plant's net primary production due to the pre-drought effect. The present results highlight the episodic effects of drought on grass growth and photosynthesis. This study will assist in understanding how degraded ecosystems can potentially cope with climate change.

Show MeSH
Leaf relative water content (RWC) under soil drought and rewatering (measured on 19 October 2005). Five SRWCs are indicated by control (75–80%), LD (6–75%), MD (50–60%), SD (35–50%), and ED (25–35%); R-MD, R-SD, and R-ED represent rewatering after the corresponding drought. All values are means ±SE for n=3–4. Bars with different lowercase letters are significantly different (P <0.05).
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fig1: Leaf relative water content (RWC) under soil drought and rewatering (measured on 19 October 2005). Five SRWCs are indicated by control (75–80%), LD (6–75%), MD (50–60%), SD (35–50%), and ED (25–35%); R-MD, R-SD, and R-ED represent rewatering after the corresponding drought. All values are means ±SE for n=3–4. Bars with different lowercase letters are significantly different (P <0.05).

Mentions: The effect of drought was determined by the leaf's RWC (F=28.065, P <0.001), and SD and ED led to significant RWC decreases, according to Duncan's multiple range test (P <0.05) (Fig. 1). As the plants under MD, SD, and ED were rewatered, leaf RWC exhibited no significant differences from well-watered plants (control treatment) (P >0.05) and within the three rewatered treatments (F=0.101, P=0.905), indicating that leaf RWC completely recovered following rewatering.


Are plant growth and photosynthesis limited by pre-drought following rewatering in grass?

Xu Z, Zhou G, Shimizu H - J. Exp. Bot. (2009)

Leaf relative water content (RWC) under soil drought and rewatering (measured on 19 October 2005). Five SRWCs are indicated by control (75–80%), LD (6–75%), MD (50–60%), SD (35–50%), and ED (25–35%); R-MD, R-SD, and R-ED represent rewatering after the corresponding drought. All values are means ±SE for n=3–4. Bars with different lowercase letters are significantly different (P <0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2736889&req=5

fig1: Leaf relative water content (RWC) under soil drought and rewatering (measured on 19 October 2005). Five SRWCs are indicated by control (75–80%), LD (6–75%), MD (50–60%), SD (35–50%), and ED (25–35%); R-MD, R-SD, and R-ED represent rewatering after the corresponding drought. All values are means ±SE for n=3–4. Bars with different lowercase letters are significantly different (P <0.05).
Mentions: The effect of drought was determined by the leaf's RWC (F=28.065, P <0.001), and SD and ED led to significant RWC decreases, according to Duncan's multiple range test (P <0.05) (Fig. 1). As the plants under MD, SD, and ED were rewatered, leaf RWC exhibited no significant differences from well-watered plants (control treatment) (P >0.05) and within the three rewatered treatments (F=0.101, P=0.905), indicating that leaf RWC completely recovered following rewatering.

Bottom Line: The results indicated that g(s) may be responsible for regulating actual photosynthetic efficiency.It is assumed that the new plant growth and photosynthetic potential enhanced by pre-drought following rewatering may try to overcompensate the great loss of the plant's net primary production due to the pre-drought effect.The present results highlight the episodic effects of drought on grass growth and photosynthesis.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Science, Beijing, PR China.

ABSTRACT
Although the relationship between grassland productivity and soil water status has been extensively researched, the responses of plant growth and photosynthetic physiological processes to long-term drought and rewatering are not fully understood. Here, the perennial grass (Leymus chinensis), predominantly distributed in the Euro-Asia steppe, was used as an experimental plant for an irrigation manipulation experiment involving five soil moisture levels [75-80, 60-75, 50-60, 35-50, and 25-35% of soil relative water content (SRWC), i.e. the ratio between present soil moisture and field capacity] to examine the effects of soil drought and rewatering on plant biomass, relative growth rate (RGR), and photosynthetic potential. The recovery of plant biomass following rewatering was lower for the plants that had experienced previous drought compared with the controls; the extent of recovery was proportional to the intensity of soil drought. However, the plant RGR, leaf photosynthesis, and light use potential were markedly stimulated by the previous drought, depending on drought intensity, whereas stomatal conductance (g(s)) achieved only partial recovery. The results indicated that g(s) may be responsible for regulating actual photosynthetic efficiency. It is assumed that the new plant growth and photosynthetic potential enhanced by pre-drought following rewatering may try to overcompensate the great loss of the plant's net primary production due to the pre-drought effect. The present results highlight the episodic effects of drought on grass growth and photosynthesis. This study will assist in understanding how degraded ecosystems can potentially cope with climate change.

Show MeSH