Chickpea （Cicer arietinum L.） Is particularly sensitive to water stress at Its reproductive phase and, under conditions of water stress, will abort flowers and pods, thus reducing yield potential. There are two type...Chickpea （Cicer arietinum L.） Is particularly sensitive to water stress at Its reproductive phase and, under conditions of water stress, will abort flowers and pods, thus reducing yield potential. There are two types of chickpea： （i） Macrocarpa （＂Kabull＂）, which has large, rams head-shaped, light brown seeds; and （11） Microcarpa （＂Desl＂）, which has small, angular and dark-brown seeds. Relatively speaking, ＂Kabull＂ has been reported to be more sensitive to water stress than ＂Desl＂. The underlying mechanisms associated with contrasting sensitivity to water stress at the metabolic level are not well understood. We hypothesized that one of the reasons for contrasting water stress sensitivity In the two types of chickpea may be a variation in oxidative injury. In the present study, plants of both types were water stressed at the reproductive stage for 14 d. As a result of the stress, the ＂Kabull＂ type exhibited an 80% reduction in seed yield over control compared with a 64% reduction observed for the ＂Desi＂ type. The decrease in leaf water potential （ψw） was faster In the ＂Kabull＂ compared with the ＂Desl＂ type. At the end of the water stress period, ψw was reduced to -2.9 and -3.1 MPa In the ＂Desi＂ and ＂Kabuli＂ types, respectively, without any significant difference between them. On the last day of stress, ＂Kabuli＂ experienced 20% more membrane injury than ＂Desi＂. The chlorophyll content and photosynthetic rate were significantly greater in ＂Desi＂ compared with ＂Kabuli＂. The malondialdehyde and H202 content were markedly higher at the end of the water stress In ＂Kabull＂ compared with ＂Desl＂, Indicating greater oxidative stress In the former. Levels of anti-oxidants, such as ascorblc acid and glutathlone, were significantly higher In ＂Desl＂ than ＂Kabull＂. Superoxide dismutase and catalase activity did not differ significantly between the two types of chickpea, whereas on the 10th day, the activities of ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase were higher in ＂Desl＂. These findings Indicate that the greater stress tolerance in the ＂Desi＂ type may be ascribed to its superior ability to maintain better water status, which results in less oxidative damage. In addlUon, laboratory studies conducted by subJecUng both types of chickpea to similar levels of polyethylene glycol-Induced water stress and to 10 μmol/L absclslc acid Indicated a greater capacity of the ＂Desi＂ type to deal with oxldaUve stress than the ＂Kabull＂ type.展开更多
基金Publication of this paper is supported by the National Natural Science Foundation of China （30424813） and Science Publication Foundation of the Chinese Academy of Sciences.
文摘Chickpea （Cicer arietinum L.） Is particularly sensitive to water stress at Its reproductive phase and, under conditions of water stress, will abort flowers and pods, thus reducing yield potential. There are two types of chickpea： （i） Macrocarpa （＂Kabull＂）, which has large, rams head-shaped, light brown seeds; and （11） Microcarpa （＂Desl＂）, which has small, angular and dark-brown seeds. Relatively speaking, ＂Kabull＂ has been reported to be more sensitive to water stress than ＂Desl＂. The underlying mechanisms associated with contrasting sensitivity to water stress at the metabolic level are not well understood. We hypothesized that one of the reasons for contrasting water stress sensitivity In the two types of chickpea may be a variation in oxidative injury. In the present study, plants of both types were water stressed at the reproductive stage for 14 d. As a result of the stress, the ＂Kabull＂ type exhibited an 80% reduction in seed yield over control compared with a 64% reduction observed for the ＂Desi＂ type. The decrease in leaf water potential （ψw） was faster In the ＂Kabull＂ compared with the ＂Desl＂ type. At the end of the water stress period, ψw was reduced to -2.9 and -3.1 MPa In the ＂Desi＂ and ＂Kabuli＂ types, respectively, without any significant difference between them. On the last day of stress, ＂Kabuli＂ experienced 20% more membrane injury than ＂Desi＂. The chlorophyll content and photosynthetic rate were significantly greater in ＂Desi＂ compared with ＂Kabuli＂. The malondialdehyde and H202 content were markedly higher at the end of the water stress In ＂Kabull＂ compared with ＂Desl＂, Indicating greater oxidative stress In the former. Levels of anti-oxidants, such as ascorblc acid and glutathlone, were significantly higher In ＂Desl＂ than ＂Kabull＂. Superoxide dismutase and catalase activity did not differ significantly between the two types of chickpea, whereas on the 10th day, the activities of ascorbate peroxidase, dehydroascorbate reductase, and glutathione reductase were higher in ＂Desl＂. These findings Indicate that the greater stress tolerance in the ＂Desi＂ type may be ascribed to its superior ability to maintain better water status, which results in less oxidative damage. In addlUon, laboratory studies conducted by subJecUng both types of chickpea to similar levels of polyethylene glycol-Induced water stress and to 10 μmol/L absclslc acid Indicated a greater capacity of the ＂Desi＂ type to deal with oxldaUve stress than the ＂Kabull＂ type.
