Abstract: Pre-treatment of germinating seeds of mung bean with 10^-4 mol/L of abscisic acid (ABA) significantly promoted adventitious root formation from rooting zone of hypocotyl cuttings of mung bean.Root number and rooting zone from each 4-day-old cutting were increased by 174% and 45%, respectively, when compared with those of the control cuttings.The enzyme activities of tryptophan aminotransferase, indole pyruvate decarboxylase and indole acetaldehyde dehydrogenase (three enzymes involved in indole acetic acid biosynthetic pathway) in rooting zone of 4-day-old hypocotyl cuttings, were increased by 49.1%, 90.6% and 105.4%, respectively, resulting in a 63.9% increase of IAA content, when compared with those of the control cuttings.Cell number in S-phase of a cell cycle in the rooting zone of 2-day-old cuttings was increased by 13% with the treatment of 10-4mol/L ABA.These results suggested that ABA was possibly promoted adventitious root formation by stimulation of DNA and IAA synthesis.

Key words: abscisic acid, hypocotyl cuttings of mung bean, cell cycle phase, auxin, adventitious root

摘要： 以10^-4 mol/L脱落酸(ABA)处理绿豆种子24 h,在幼苗下胚轴长6 cm时,切除根部作为插条,研究ABA对插条不定根发生及插条基部细胞周期时相的影响。结果表明,ABA可促进下胚轴插条不定根发生,增加生根数和生根范围;ABA提高插条基部细胞色氨酸转氨酶、吲哚丙酮酸脱羧酶和吲哚乙醛脱氢酶的比活性,增加吲哚乙酸含量,同时进入细胞周期S期的基部细胞数目增加,促进DNA合成,有利于不定根的发生。

关键词: 脱落酸, 绿豆下胚轴, 细胞周期时相, 生长素, 不定根