Photosynthetic Recovery of a Perennial Grass Leymus chinensis after Different Periods of Soil Drought

Plant Production Science

Zhen-Zhu Xu¹  Guang-Sheng Zhou¹ 

[1] (Key Laboratory of Vegetation and Environmental Change, Institute of Botany;

关键词: Carbonic anhydrase;    Chlorophyll fluorescence;    Drought adaptation;    Gas exchange;    Leymus chinensis(Trin.) Tzvel.;    Rewatering;   

DOI  :  10.1626/pps.10.277

来源: DOAJ

【 摘 要 】

The effects of rewatering after different periods of soil drought stress on the photosynthetic capacity of Leymus chinensis in pots were investigated. The plants were subjected to short-term (10-d), moderate-term (20-day) and long-term (30-d) drought each followed by rewatering. Control plants were well watered during the experimental periods. The long-term water stress without rewatering decreased the chlorophyll content, Chl a/b ratio, carbonic anhydrase (CA) activity, net photosynthetic rate (A), and leaf area compared with the control. Rewatering increased the ratio of Chl a/b, CA activity and A, but decreased the leaf area and ion leakage from the cut leaf pieces. The long-term water stress without rewatering reduced the maximal efficiency of PSII (Fv/Fm), the actual quantum yield (Φp), and photochemical quenching (qp), but these values were increased by rewatering to more than the control level, though non-photochemical quenching (qN) was decreased as compared with the control. This implied that long-term drought aggravated PSII, but rewatering improved it. The net CO2-exchange rate showed similar diurnal changes in all treatments, but the rate in the morning was lower in long-term drought (before rewatering) than in the other treatments. These results suggest the photosynthesis of Leymus chinensis may be well adapted to episodical soil drought.

【 授权许可】

Unknown