Rapid recovery of photosynthetic rate following soil water deficit and re-watering in cotton plants (Gossypium herbaceum L.) is related to the stability of the photosystems.
The responses of gas exchange, chlorophyll fluorescence and the anti-oxidative system of cotton leaves were studied during water deficit and recovery. The results show that water deficit led to a reversible reduction in the photosynthetic rate. This reduction was mainly accompanied by stomatal limitation. The activity of photosystem II (PSII) and photosystem I (PSI) was relatively stable during water deficit and recovery. Water deficit caused an enhanced production of reactive oxygen species (ROS) and increased lipid peroxidation. Proline accumulation and the anti-oxidative enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POD), along with the antioxidant ascorbate (AsA), increased during water deficit. On re-watering, the ROS generation rate, anti-oxidative enzymes activities and the extent of the lipid peroxidation returned to near control values. Overall, rapid recovery of the photosynthetic rate is related to the stability of the photosystems which appears to be a critical mechanism allowing cotton plants to withstand and survive drought environments.
['Yi|Xiao-Ping|XP|', 'Zhang|Ya-Li|YL|', 'Yao|He-Sheng|HS|', 'Luo|Hong-Hai|HH|', 'Gou|Ling|L|', 'Chow|Wah Soon|WS|', 'Zhang|Wang-Feng|WF|']
D000222:Adaptation, Physiological D000975:Antioxidants D060387:Ascorbate Peroxidases D002734:Chlorophyll D055864:Droughts D003368:Gossypium D015227:Lipid Peroxidation D009195:Peroxidase D010788:Photosynthesis D045331:Photosystem I Protein Complex D045332:Photosystem II Protein Complex D018515:Plant Leaves D017382:Reactive Oxygen Species D012987:Soil D013312:Stress, Physiological D013482:Superoxide Dismutase D014867:Water
Water deficit Re-watering Cotton Photosynthesis ROS metabolism