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Gibberellin‐induced elongation and osmoregulation in internodes of floating rice
Author(s) -
Azuma Tetsushi,
Ueno Satoshi,
Uchida Naotsugu,
Yasuda Takeshi
Publication year - 1997
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1997.tb05351.x
Subject(s) - plant stem , elongation , osmoregulation , invertase , gibberellic acid , biology , gibberellin , botany , sugar , osmotic pressure , ethylene , oryza sativa , horticulture , chemistry , biochemistry , enzyme , germination , ultimate tensile strength , salinity , materials science , ecology , metallurgy , gene , catalysis
Internodal elongation in floating rice ( Oryza sativa L. cv. Habiganj Aman II) is known to be enhanced by treatment with ethylene or gibberellic acid (GA 3 ) at high relative humidity (RH). However, ethylene‐induced internodal elongation is inhibited at low RH. while GA 3 ‐induced internodal elongation is hardly affected by humidity. We examined the possible involvement of osmoregulation in the stimulation by GA 3 of the elongation of internodes at low RH. Submergence and treatment with ethylene or GA3 3 at 100% RH increased the osmotic potential in internodes of excised stem segments, while GA 3 at 20% RH maintained the osmotic potential at a low level. In internodes of stem segments that had been treated with GA 3 at 20% RH, the activity of invertase and the level of soluble sugars were almost 2‐ and 1.5‐fold higher, respectively, than those in internodes that had been treated with GA 3 at 100% RH. These results indicate that one of the possible mechanisms by which GA 3 promotes elongation of internodes at low RH involves the osmoregulation that is achieved by promotion of the synthesis of invertase.