拟南芥突变体amos2对外源激素的响应特征研究

检测拟南芥突变体amos2对外源激素响应的结果表明，该突变体主根伸长对外源生长素有明显的抗性，其主根抗性强于拟南芥野生型(WT)，但弱于已知的生长素突变体aux1-7和axr4-2。该突变体的主根伸长对生长素转运抑制剂TIBA也表现出较强抗性，而对一定浓度的ACC表现敏感，但主根伸长对外源6-BA和ABA的响应与野生型一致。外源添加生长素或乙烯抑制剂可同时增加amos2和野生型的可见侧根数量，但突变体的增加百分比要显著高于野生型。虽然amos2突变体的荚果败育率比野生型显著增加，但并未表现出其他生长素突变体特有的胚轴弯钩消失及根系向重性缺失的表型。上述结果暗示突变基因AMOS2在控制拟南芥生长发育的某些方面发挥重要作用。

The Response Characteristics of Arabidopsis Mutant amos2 to Exogenous Hormones

In this study, The response characteristics of the primary root and lateral root to exogenous hormones in Arabidopsis wild type and amos2 mutant were investigated. The primary root elongation of mutant seedlings was less inhibited than wild-type root over a range of synthetic auxin 2,4-D concentrations; the auxin response of the amos2 mutant was also comparable to that of two auxin-related mutants aux1-7 and axr4-2, and the both known mutants, aux1-7 and axr4-2, were more insensitive than amos2. The amos2 mutant was also resistant to auxin transport inhibitor TIBA but hypersensitive to the ethylene precursor ACC. The amos2 mutant did not show signficant differences from wild type in root elongation responses to cytokinin benzyl adenine (6-BA) and abscisic acid (ABA). Exogenous auxin and ethylene antagonist Ag+ strongly induced lateral root formation in both wild-type and amos2 seedlings, but there were slightly but signi?cantly higher levels of lateral root induction in amos2 seedlings than that of wild-type plants. The amos2 mutant displayed low fertility rates in the early stage of development, but the amos2 mutant was not different from the wild type in gravitropism and hookless hypocotyl. All the results suggested that AMOS2 plays a role in the regulation of lateral root and flower development under normal growth conditions.