title: [Physiological response and salt-tolerance of Gleditsia microphylla under NaCl stress].
abstract: In order to exploit the salt-tolerance ability and mechanism of Gleditsia microphylla, the plant growth, cell membrane permeability, the activities of cell protective enzymes, and the distri- butions of Na+ and K+ in different tissues were investigated under various NaCl stress (0.053%, 0.15%, 0.3%, 0.45% and 0.6%) with potted two-year seedlings. The results were as follows: With the increase of NaCl concentration, the seedling growth decreased while the salt injured index in- creased, and the salt-tolerance thresholds of seedling was 0.42% NaCl. With the NaCl concentration increasing, the membrane permeability, superoxide anion radical generating rate and MDA content increased grandly, while the activities of SOD, POD and CAT demonstrated an increase-decrease curve which reached the peak at 0.3% or 0.45%. Under the high salt stress condition, the supero- xide anion could be consumed timely by increasing the activities of SOD, POD and CAT enzymes, which was useful to avoid cell injure. Under salt stress condition, the Na+ content in different tissues increased gradually, following the order of root > leaf > stem, and the K+ content and K+/Na+ in different tissues decreased, following the order of leaf > root > stem. The K+-Na+ selective transpor- tation coefficients (S(K+) · Na+) of stem and leaf tissues under the soil NaCl stress condition were both increased, following the order of leaf > stem. In conclusion, the findings suggested that the salt- adaptation mechanisms of G. microphylla were root salt-rejection by Na+ accumulation and restriction in root tissue and leaf salt-tolerance by a remarkably increased ability of K+ selective absorption and accumulation in leaf tissue.
authors.forename: Bin
authors.initials: B
authors.lastname: Lu
authors.forename: Yue-min
authors.initials: YM
authors.lastname: Hou
authors.forename: Xin-yang
authors.initials: XY
authors.lastname: Li
authors.forename: Yue-xia
authors.initials: YX
authors.lastname: Chang
authors.forename: Da-zhuang
authors.initials: DZ
authors.lastname: Huang
authors.forename: Bing-she
authors.initials: BS
authors.lastname: Lu
mesh_terms: D031501:Gleditsia / Q000502:physiology*; D007477:Ions; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D055049:Salt Tolerance; D036226:Seedlings; D012964:Sodium / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D013312:Stress, Physiological
chemical_list: D007477:Ions; D012987:Soil; D012965:Sodium Chloride; D012964:Sodium; D011188:Potassium