Wang Yi-Ming, Wang You-Nian, Shi Guang-Lu, Du Dong, Liu Rui-Dong, Yang Ai-Zhen, Ge Shui-Lian, Meng Hai-Ling
Department of Plant Science and Technology, Beijing University of Agriculture, Beijing 102206, China.
Ying Yong Sheng Tai Xue Bao. 2007 Mar;18(3):542-8.
With four-year-old potted Prunus persica L. cv. Qingfeng as test material, this paper studied the change pattern of its leaf betaine content under water stress, and its physiological responses under effects of foliage-spraying exogenous betaine. The results showed that under normal water supply, the betaine content in Qingfeng' s leaf was 75.9-80.5 microg x g(-1) FM, which was increased with increasing water stress, and up to 278.9 microg x g(-1) FM on the 16th day after cutting off the water supply. The leaf plasma membrane permeability was 8.06% - 8.61% under normal water supply, but increased to 28.62% under water stress. When 100 and 500 mg x L(-1) of betaine were applied exogenously, the plasma membrane permeability was 26.25% and 21.79% after 16 days, respectively. The hydrogen peroxide (H2O2) content increased from 27.2-32.5 micromol g(-1) FM to 76.4 micromol x g(-1) FM in the course of water stress, and decreased to 73.2 and 68.5 micromol x g(-1) FM after spraying 100 and 500 mg betaine x L(-1), respectively. During the period of intensified water stress, the peak value of ascorbate peroxidase (AsA-POD) activity was 0.435 mg x g(-1) FM, and up to 0.490 mg x g(-1) FM when treated with exogenous betaine. When the peach tree was subjected to water stress, the contents of free proline and soluble sugar accumulated dramatically, but produced on approximately decrease in 500 mg x L(-1) endogenous betaine application on the 16th day which was slightly less than that of control and 100 mg x L(-1) betaine application. There was a gradual decline in the content of soluble protein under water stress, and an increment of 20. 3% was observed when betaine was applied exogenously. These results strongly suggested that foliage-spraying exogenous betaine could increase the drought resistance of peach tree through decreasing its leaf plasma membrane permeability and H2O2, free proline and soluble sugar contents and increasing its leaf AsA-POD activity and soluble protein content.
以4年生盆栽‘清风’桃为试材，研究了水分胁迫下其叶片甜菜碱含量的变化规律以及喷施外源甜菜碱后的生理响应。结果表明，正常供水条件下，‘清风’桃叶片甜菜碱含量为75.9 - 80.5 μg·g-1FW，随水分胁迫加剧而升高，停水16 d时达278.9 μg·g-1FW。正常供水时叶片质膜透性为8.06% - 8.61%，水分胁迫下增至28.62%。外源喷施100、500 mg·L-1甜菜碱后，16 d时质膜透性分别为26.25%和21.79%。水分胁迫过程中过氧化氢（H2O2）含量从27.2 - 32.5 μmol·g-1FW增至76.4 μmol·g-1FW，喷施100 和500 mg·L-1甜菜碱后分别降至73.2和68.5 μmol·g-1FW。水分胁迫加剧期，抗坏血酸过氧化物酶（AsA-POD）活性峰值为0.435 mg·g-1FW，外源甜菜碱处理后达0.490 mg·g-1FW。桃树受水分胁迫时，游离脯氨酸和可溶性糖含量大幅积累，但在停水16 d时，喷施500 mg·L-1内源甜菜碱的含量略有下降，略低于对照和喷施100 mg·L-1甜菜碱的处理。水分胁迫下可溶性蛋白质含量逐渐下降，外源喷施甜菜碱后增加了20.3%。这些结果有力地表明，喷施外源甜菜碱可通过降低桃树叶片质膜透性、H2O2、游离脯氨酸和可溶性糖含量，提高叶片AsA-POD活性和可溶性蛋白质含量，从而增强桃树的抗旱性。
