Variability of mesophyll conductance and its relationship with water use efficiency in cotton leaves under drought pretreatment.
Drought slows net photosynthetic rate (AN) but increases water use efficiency (WUE). Farmers give an artificial drought pretreatment to some crops in the early growth stage and find that yield increases accompanying with the improvement of WUE. We conducted well-watered, non-drought, mild drought and moderate drought pretreatments of potted cotton cultivars. The aims of the present study were to analyse the importance of mesophyll conductance (gm) as a factor that may simultaneously improve AN and WUE under drought pretreatment conditions, and to analyse the role of anatomical structure and biochemical mechanism in the variability of gm. Our results showed that significant variability of gm estimated by gas exchange and chlorophyll fluorescence was observed between non-drought pretreatment and drought pretreatment associated with change in AN and WUE. There was great difference in anatomical structure and expression of aquaporins (GhAQP1) among all the treatments. In addition, expression of carbonic anhydrase (CA) may not be important in the regulation of gm under drought pretreatment conditions. We concluded that the variability of gm offers a potential target for improving leaf AN and WUE simultaneously by the regulation of anatomical structure and GhAQP1.
The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi 832003, China.
Ji-Mei
JM
Han
The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi 832003, China.
Hao-Feng
HF
Meng
Key Laboratory of Plant Resources, Chinese Academy of Sciences, Beijing 100093, China.
Sai-Yu
SY
Wang
Key Laboratory of Plant Resources, Chinese Academy of Sciences, Beijing 100093, China.
Chuang-Dao
CD
Jiang
The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi 832003, China.
Feng
F
Liu
The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi 832003, China.
Wang-Feng
WF
Zhang
The Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Group, Shihezi University, Shihezi 832003, China. Electronic address: zhangyali_cn@foxmail.com.
Ya-Li
YL
Zhang
D051398:Aquaporin 1 / Q000235:genetics; D002256:Carbonic Anhydrases / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D003368:Gossypium / Q000502:physiology*; D058503:Mesophyll Cells / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics; D054046:Plant Stomata / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology*; D014867:Water / Q000378:metabolism*
D010940:Plant Proteins; D014867:Water; D051398:Aquaporin 1; D002256:Carbonic Anhydrases
Anatomical structure; Aquaporin; Cotton; Drought pretreatments; Mesophyll conductance; Stomatal conductance; Water use efficiency