Class C ARFs evolved before the origin of land plants and antagonize differentiation and developmental transitions in Marchantia polymorpha
Class C ARFs evolved before the origin of land plants and antagonize differentiation and developmental transitions in Marchantia polymorpha
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DOI：
10.1111/nph.15090
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发表时间：
2018-06-01
期刊：
影响因子：
9.4
通讯作者：
Bowman, John L.
中科院分区：
文献类型：
--
作者：
Flores-Sandoval, Eduardo;Eklund, D. Magnus;Bowman, John L.
陆地植物的大量发育和生理过程都受到生长素的影响，很大程度上是通过生长素响应因子（ARF）改变基因表达来影响的。经典的生长素转录反应系统是陆地植物的创新，然而，轮藻类藻类至少拥有某些 ARF 和 AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) 基因的直系同源物，这表明经典陆地植物系统的元素存在于祖先藻类中。地钱中存在单独的 C 类 ARF，MpARF3。系统发生分析表明，祖先藻类中存在多个 ARF 类，包括 C 类 ARF。功能丧失和获得功能的 MpARF3 等位基因会在配子体中产生多效性效应，MpARF3 会抑制生命周期多个阶段的分化和发育转变。尽管功能丧失的 Mparf3 和 Mpmir160 等位基因对外源生长素处理有反应，但强 miR 抗性的 MpARF3 等位基因对生长素不敏感，表明 C 类 ARF 以上下文依赖的方式起作用。我们得出结论，两个模块独立进化以调节预先存在的 ARF 转录网络。生长素-TIR1-AUX/IAA 通路进化为抑制 A/B 类 ARF 活性，而 miR160 进化为以动态方式抑制 C 类 ARF。
A plethora of developmental and physiological processes in land plants is influenced by auxin, to a large extent via alterations in gene expression by AUXIN RESPONSE FACTORs (ARFs). The canonical auxin transcriptional response system is a land plant innovation, however, charophycean algae possess orthologues of at least some classes of ARF and AUXIN/INDOLE- 3-ACETIC ACID (AUX/IAA) genes, suggesting that elements of the canonical land plant system existed in an ancestral alga.We reconstructed the phylogenetic relationships between streptophyte ARF and AUX/IAA genes and functionally characterized the solitary class C ARF, MpARF3, in Marchantia polymorpha.Phylogenetic analyses indicate that multiple ARF classes, including class C ARFs, existed in an ancestral alga. Loss- and gain-of-function MpARF3 alleles result in pleiotropic effects in the gametophyte, with MpARF3 inhibiting differentiation and developmental transitions in multiple stages of the life cycle. Although loss-of-function Mparf3 and Mpmir160 alleles respond to exogenous auxin treatments, strong miR-resistant MpARF3 alleles are auxininsensitive, suggesting that class C ARFs act in a context-dependent fashion.We conclude that two modules independently evolved to regulate a pre-existing ARF transcriptional network. Whereas the auxin-TIR1-AUX/IAA pathway evolved to repress class A/B ARF activity, miR160 evolved to repress class C ARFs in a dynamic fashion.