Koch B L, Moore T C
Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331.
Plant Physiol. 1990 Aug;93(4):1663-4. doi: 10.1104/pp.93.4.1663.
Maximum elongation of excised internodal stem sections of light-grown pea (Pisum sativum L.) seedlings occurred at 10(-5) molar indoleacetic acid (IAA), with submaximal responses occurring at 10(-4) and 10(-3) molar. Accompanying elongation at concentrations of IAA of 10(-6) to 10(-3) molar was production of ethylene, with the amount increasing up to 10(-4) molar IAA and then becoming nearly constant. Elongation of light-grown sections was not inhibited by exogenous ethylene up to 10,000 ppm in the presence of 10(-5) molar IAA. Marked (up to 50%) inhibition of elongation of internodal segments in situ was observed after treating whole light-grown seedlings with exogenous ethylene for 20 hours. It is concluded that ethylene is not responsible for the submaximal elongation responses of green pea stem sections at high auxin concentrations, but that IAA per se is accountable.
光照培养的豌豆（Pisum sativum L.）幼苗节间茎切段的最大伸长发生在10⁻⁵摩尔吲哚乙酸（IAA）时，在10⁻⁴和10⁻³摩尔时出现次最大反应。在IAA浓度为10⁻⁶至10⁻³摩尔时，伴随着伸长会产生乙烯，其产量在IAA达到10⁻⁴摩尔之前增加，然后几乎保持恒定。在10⁻⁵摩尔IAA存在的情况下，高达10000 ppm的外源乙烯不会抑制光照培养切段的伸长。在用外源乙烯处理光照培养的完整幼苗20小时后，观察到节间切段伸长有明显（高达50%）的抑制。得出的结论是，乙烯不是高生长素浓度下绿色豌豆茎切段次最大伸长反应的原因，而是IAA本身起作用。
