Inhibition of lamina outgrowth following Solanum lycopersicum AUXIN RESPONSE FACTOR 10 (SlARF10) derepression
Inhibition of lamina outgrowth following Solanum lycopersicum AUXIN RESPONSE FACTOR 10 (SlARF10) derepression
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DOI：
10.1007/s11103-012-9883-4
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发表时间：
2012-04-01
影响因子：
5.1
通讯作者：
Arazi, T.
中科院分区：
文献类型：
--
作者：
Hendelman, A.;Buxdorf, K.;Arazi, T.
生长素应答因子（ARF）是一类能激活或抑制生长素应答基因表达的转录因子，在生长素介导的植物发育过程中发挥重要作用。在这里，我们确定和特点的番茄（番茄）ARF 10同源物（SlARF 10），证明它是转录后调控的Sl-miR 160，并调查这种调节番茄发育的意义。在野生型番茄中，SlARF 10主要在成熟和成熟果实的果皮中表达，显示出与Sl-miR 160互补的表达谱。野生型SlARF 10的组成型表达没有改变番茄的发育。然而，组成型表达Sl-miR 160 a抗性版本（mSlARF 10）的转基因番茄植物发育出狭窄的小叶叶片、萼片和花瓣以及形状异常的果实。在复叶发育过程中，mSlARF 10积累特异性抑制小叶叶片生长，而不影响其他生长素驱动的过程，如小叶起始和裂片形成。此外，叶片大小与mSlARF 10转录水平呈负相关，这强烈暗示了定位于细胞核的SlARF 10蛋白可以作为小叶叶片生长的转录抑制因子。因此，已知的促进细胞生长的生长素应答基因在积累增加的mSlARF 10水平的茎尖中下调。综上所述，我们认为Sl-miR 160对SlARF 10的抑制对于生长素介导的叶片生长和早期果实发育是必不可少的。
Auxin response factors (ARFs) are plant transcription factors that activate or repress the expression of auxin-responsive genes and accordingly, play key roles in auxin-mediated developmental processes. Here we identified and characterized the Solanum lycopersicum (tomato) ARF10 homolog (SlARF10), demonstrated that it is post-transcriptionally regulated by Sl-miR160, and investigated the significance of this regulation for tomato development. In wild-type tomato, SlARF10 is primarily expressed in the pericarp of mature and ripened fruit, showing an expression profile complementary to that of Sl-miR160. Constitutive expression of wild-type SlARF10 did not alter tomato development. However, transgenic tomato plants that constitutively expressed the Sl-miR160a-resistant version (mSlARF10) developed narrow leaflet blades, sepals and petals, and abnormally shaped fruit. During compound leaf development, mSlARF10 accumulation specifically inhibited leaflet blade outgrowth without affecting other auxin-driven processes such as leaflet initiation and lobe formation. Moreover, blade size was inversely correlated with mSlARF10 transcript levels, strongly implying that the SlARF10 protein, which was localized to the nucleus, can function as a transcriptional repressor of leaflet lamina outgrowth. Accordingly, known auxin-responsive genes, which promote cell growth, were downregulated in shoot apices that accumulated increased mSlARF10 levels. Taken together, we propose that repression of SlARF10 by Sl-miR160 is essential for auxin-mediated blade outgrowth and early fruit development.