Phytochrome Regulation of Branching in Arabidopsis
Phytochrome Regulation of Branching in Arabidopsis
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DOI：
10.1104/pp.109.148833
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发表时间：
2010-04-01
期刊：
影响因子：
7.4
通讯作者：
Casal, Jorge J.
中科院分区：
文献类型：
--
作者：
Finlayson, Scott A.;Krishnareddy, Srirama R.;Casal, Jorge J.
光敏色素感知的红光：远红光比例控制着植物结构的可塑性状，包括分枝。尽管分枝对于植物适应性和生产力具有重要意义，但关于拟南芥（Arabidopsis thaliana）中光敏色素控制分枝反应的定量和机制信息很少。在这里，我们发现，在拟南芥中，光敏色素 B 突变和低红光：远红光比对分枝的负面影响很大程度上是由于芽生长能力降低和作用于芽的相关抑制程度增加，而不是由于可用于分枝的叶子和芽数量减少。光敏色素对相关抑制程度的影响需要功能性 BRANCHED1 (BRC1)、BRC2、AXR1、MORE AXILLARY GROWTH2 (MAX2) 和 MAX4。对选定芽中基因表达的分析表明，BRC1 和 BRC2 是不同基因网络的一部分。 BRC1网络与特定芽的生长能力有关，而BRC2网络与分枝之间的生长协调有关。我们得出的结论是，分支整合子 BRC1 和 BRC2 对于光敏色素的反应是必需的，但它们对这些反应的贡献不同，可能通过不同的途径发挥作用。
The red light: far-red light ratio perceived by phytochromes controls plastic traits of plant architecture, including branching. Despite the significance of branching for plant fitness and productivity, there is little quantitative and mechanistic information concerning phytochrome control of branching responses in Arabidopsis (Arabidopsis thaliana). Here, we show that in Arabidopsis, the negative effects of the phytochrome B mutation and of low red light: far-red light ratio on branching were largely due to reduced bud outgrowth capacity and an increased degree of correlative inhibition acting on the buds rather than due to a reduced number of leaves and buds available for branching. Phytochrome effects on the degree of correlative inhibition required functional BRANCHED1 (BRC1), BRC2, AXR1, MORE AXILLARY GROWTH2 (MAX2), and MAX4. The analysis of gene expression in selected buds indicated that BRC1 and BRC2 are part of different gene networks. The BRC1 network is linked to the growth capacity of specific buds, while the BRC2 network is associated with coordination of growth among branches. We conclude that the branching integrators BRC1 and BRC2 are necessary for responses to phytochrome, but they contribute differentially to these responses, likely acting through divergent pathways.