Auxin-induced degradation dynamics set the pace for lateral root development
Auxin-induced degradation dynamics set the pace for lateral root development
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DOI：
10.1242/dev.117234
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发表时间：
2015-03-01
期刊：
影响因子：
4.6
通讯作者：
Nemhauser, Jennifer L.
中科院分区：
文献类型：
--
作者：
Guseman, Jessica M.;Hellmuth, Antje;Nemhauser, Jennifer L.
生长素通过 Aux/IAA 共阻遏物降解引发的简单核信号传导途径引发多种细胞行为。我们之前的工作表明，拟南芥 Aux/IAA 大家族的成员在合成环境中表现出一系列降解率。然而，Aux/IAA 周转率的差异是否在植物对生长素的反应中发挥重要作用仍然是一个悬而未决的问题。在这里，我们使用成熟的侧根发育模型来直接检验以下假设：生长素诱导的 Aux/IAA 周转率决定了生长素调节的发育事件的速度。我们通过生成表达 IAA14 降解率变体的转基因植物来做到这一点，IAA14 是侧根萌生的关键决定因素。侧根发育成熟阶段的进展与 IAA14 周转率的工程化密切相关，从而得出结论：Aux/IAA 是生长素启动的计时器，可同步发育转变。
Auxin elicits diverse cell behaviors through a simple nuclear signaling pathway initiated by degradation of Aux/IAA co-repressors. Our previous work revealed that members of the large Arabidopsis Aux/IAA family exhibit a range of degradation rates in synthetic contexts. However, it remained an unresolved issue whether differences in Aux/IAA turnover rates played a significant role in plant responses to auxin. Here, we use the well-established model of lateral root development to directly test the hypothesis that the rate of auxin-induced Aux/IAA turnover sets the pace for auxin-regulated developmental events. We did this by generating transgenic plants expressing degradation rate variants of IAA14, a crucial determinant of lateral root initiation. Progression through the well-established stages of lateral root development was strongly correlated with the engineered rates of IAA14 turnover, leading to the conclusion that Aux/IAAs are auxin-initiated timers that synchronize developmental transitions.