Comparative genetic studies on the APRR5 and APRR7 genes belonging to the APRR1/TOC1 quintet implicated in circadian rhythm, control of flowering time, and early photomorphogenesis.
Comparative genetic studies on the APRR5 and APRR7 genes belonging to the APRR1/TOC1 quintet implicated in circadian rhythm, control of flowering time, and early photomorphogenesis.
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DOI：
10.1093/pcp/pcg148
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发表时间：
2003-11
影响因子：
4.9
通讯作者：
Yoko Yamamoto;Eriko Sato;Tomo Shimizu;N. Nakamich;Shusei Sato;Tomohiko Kato;S. Tabata;A. Nagatani-A.-N
中科院分区：
文献类型：
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作者：
Yoko Yamamoto;Eriko Sato;Tomo Shimizu;N. Nakamich;Shusei Sato;Tomohiko Kato;S. Tabata;A. Nagatani-A.-N
在拟南芥中，已经确定了许多与昼夜节律相关的因素。其中，TOC1 （TIMING OF CAB EXPRESSION 1）被认为是中心振荡器的一个组成部分。TOC1是拟南芥伪反应调节蛋白（APRR1/TOC1、APRR3、APRR5、APRR7和APRR9）小家族的成员。尽管如此，目前尚不清楚APRR1/TOC1以外的APRR家族成员是否也与昼夜节律的机制有关。为了进一步解决这个问题，我们对一组T-DNA插入突变体进行了表征，每个突变体都被认为在五种基因（即APRR5和APRR7）中都有严重的病变。对于这些突变体（aprr5-11和aprr7-11），我们证明了一个给定的突变，如果不是直接的，单独地，同时影响与昼夜节律相关的生物事件：(i)长白天光周期条件下的开花时间，（ii）早期光形态形成期间幼苗的红光敏感性，以及（iii）某些时钟控制基因（包括CCA1和APRR1/TOC1）在恒定白光下的自由运行节律期。这些结果表明，尽管APRR1/TOC1以外的五个成员可能不会直接整合到中心振荡器的框架中，但它们对于更好地理解拟南芥生物钟的分子机制至关重要。
In Arabidopsis thaliana, a number of circadian-associated factors have been identified. Among those, TOC1 (TIMING OF CAB EXPRESSION 1) is believed to be a component of the central oscillator. TOC1 is a member of a small family of proteins, designated as Arabidopsis PSEUDO-RESPONSE REGULATORS (APRR1/TOC1, APRR3, APRR5, APRR7, and APRR9). Nonetheless, it is not very clear whether or not the APRR family members other than APRR1/TOC1 are also implicated in the mechanisms underlying the circadian rhythm. To address this issue further, here we characterized a set of T-DNA insertion mutants, each of which is assumed to have a severe lesion in each one of the quintet genes (i.e. APRR5 and APRR7). For each of these mutants (aprr5-11 and aprr7-11) we demonstrate that a given mutation singly, if not directly, affects the circadian-associated biological events simultaneously: (i) flowering time in the long-day photoperiod conditions, (ii) red light sensitivity of seedlings during the early photomorphogenesis, and (iii) the period of free-running rhythms of certain clock-controlled genes including CCA1 and APRR1/TOC1 in constant white light. These results suggest that, although the quintet members other than APRR1/TOC1 may not be directly integrated into the framework of the central oscillator, they are crucial for a better understanding of the molecular mechanisms underlying the Arabidopsis circadian clock.