Enhancement of transpiration by ethylene is responsible for absence of internodal elongation in floating rice at low humidity.
Internodal elongation in floating rice (Oryza sativa) is known to be enhanced by treatment with ethylene or gibberellic acid (GA3) at high relative humidity (RH). However, ethylene-induced internodal elongation is inhibited at low RH, while GA3-induced internodal elongation is hardly affected by humidity. We examined the effects of ethylene and GA3 on the rate of transpiration in stem segments incubated at 30% or 100% RH. Ethylene promoted the transpiration of stem segments at 30% RH, but not at 100% RH, while GA3 had little effect on transpiration at either 30% or 100% RH. We propose that the absence of ethylene-induced internodal elongation at low RH is due, at least in part, to ethylene-induced transpiration.
Azuma
Tetsushi
T
Graduate School of Science and Technology, Kobe University, Nada-ku, Kobe 657-8501, Japan. azuma@kobe-u.ac.jp
Hatanaka
Tomoko
T
Uchida
Naotsugu
N
Yasuda
Takeshi
T
D000040:Abscisic Acid / Q000378:metabolism; D005030:Ethylenes / Q000494:pharmacology*; D005875:Gibberellins / Q000494:pharmacology; D006813:Humidity; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D014867:Water / Q000378:metabolism
D005030:Ethylenes; D005875:Gibberellins; D014867:Water; D000040:Abscisic Acid; C036216:ethylene; C007842:gibberellic acid