Loss of Responsiveness to Osmotic Stress in Maize Root:the Effect of Water Channel Blocker HgCl_2  

作　　者：ZHU Jian-jun BAI Xin-fu ZHANG Ping WANG Yan-hua 

机构地区：[1]College of Life Sciences, Ludong University, Yantai 264025, P.R.China

出　　处：《Agricultural Sciences in China》2010年第8期1230-1235,共6页中国农业科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (30471044)

摘　　要：In order to investigate the effect of water channel blocker HgCl2 on the hydraulic resistance in roots of maize seedlings, a xylem pressure probe was used to monitor the changes in root xylem pressure in response to NaCl- or mannitol-induced osmotic stresses before and after the application of HgCl2. When the maize roots were subjected to 500 umol L-1 HgCl2 in root bathing solution, not only a considerable decline in xylem pressure （increase in xylem tension） was observed, but the loss of responsiveness of the plant to both salt- and mannitol-induced osmotic stresses in terms of xylem pressure change was seen as well when the transpiration rate of the plant was not significantly changed. The results are similar but different from the reversed osmosis by the Fenton reaction in the internodes of Chara coralline, showing that the mechanisms of water transport across cell membrane in plant roots are far more complicated than expected.In order to investigate the effect of water channel blocker HgCl2 on the hydraulic resistance in roots of maize seedlings, a xylem pressure probe was used to monitor the changes in root xylem pressure in response to NaCl- or mannitol-induced osmotic stresses before and after the application of HgCl2. When the maize roots were subjected to 500 umol L-1 HgCl2 in root bathing solution, not only a considerable decline in xylem pressure （increase in xylem tension） was observed, but the loss of responsiveness of the plant to both salt- and mannitol-induced osmotic stresses in terms of xylem pressure change was seen as well when the transpiration rate of the plant was not significantly changed. The results are similar but different from the reversed osmosis by the Fenton reaction in the internodes of Chara coralline, showing that the mechanisms of water transport across cell membrane in plant roots are far more complicated than expected.

关 键 词：AQUAPORIN maize root mercury chloride xylem pressure osmotic stress 

分 类 号：Q945.78[生物学—植物学] X510.323.5[环境科学与工程—环境工程]