Extended Vernalization Regulates Inflorescence Fate in Arabis alpina by Stably Silencing PERPETUAL FLOWERING1
Extended Vernalization Regulates Inflorescence Fate in Arabis alpina by Stably Silencing PERPETUAL FLOWERING1
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DOI：
10.1104/pp.17.01754
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发表时间：
2018-04-01
期刊：
影响因子：
7.4
通讯作者：
Albani, Maria C.
中科院分区：
文献类型：
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作者：
Lazaro, Ana;Obeng-Hinneh, Evelyn;Albani, Maria C.
高山多年生南芥在长期暴露于寒冷的情况下会萌发花蕾。在加入Pajares，我们表明，春化的长度影响开花时间和花序的命运，但不影响维持营养生长的腋生枝。在春化过程中，花器官识别基因的表达在主茎尖逐渐增加，与花的承诺增加。在北方拟南芥（Arabidopsis thaliana）中，春化作用的长度调节花抑制子FLOWERYLOCUS C（FLC）的稳定沉默。我们证明了FLC的直系同源基因PEP 1在A.阿尔卑斯山，同样受到暴露于寒冷的持续时间的影响。延长春化导致花序中PEP 1的稳定沉默。相反，不充分的春化导致PEP 1重新激活后，冷处理，这与延迟开花和花逆转表型，如苞片和营养花序分支的外观。花逆转表型减少的pep 1 -1突变体，表明PEP 1调节春化后的花序的命运。春化持续时间对PEP 1稳定沉默的影响是特定于在冷处理期间启动开花的分生组织。延长春化不能沉默PEP 1的幼苗和腋生枝，从芽开始在冷处理，保持营养。因此，春化时间对A. alpina在花序和腋生枝中差异调节PEP 1。PEP 1具有调节分生组织命运的双重作用;它阻止分生组织开花并拮抗春化后的花序发育。
The alpine perennial Arabis alpina initiates flower buds during prolonged exposure to cold. In the accession Pajares, we demonstrate that the length of vernalization influences flowering time and inflorescence fate but does not affect the axillary branches that maintain vegetative growth. The expression of floral organ identity genes gradually increases in the main shoot apex during vernalization, correlating with an increase in floral commitment. In northern Arabidopsis (Arabidopsis thaliana) accessions, the length of vernalization modulates the stable silencing of the floral repressor FLOWERING LOCUS C (FLC). We demonstrate that expression of PERPETUAL FLOWERING1 (PEP1), the ortholog of FLC in A. alpina, is similarly influenced by the duration of the exposure to cold. Extended vernalization results in stable silencing of PEP1 in the inflorescence. In contrast, insufficient vernalization leads to PEP1 reactivation after cold treatment, which correlates with delayed flowering and the appearance of floral reversion phenotypes such as bracts and vegetative inflorescence branches. Floral reversion phenotypes are reduced in the pep1-1 mutant, suggesting that PEP1 regulates the fate of the inflorescence after vernalization. The effect of vernalization duration on stable silencing of PEP1 is specific to meristems that initiate flowering during cold treatment. Extended vernalization fails to silence PEP1 in young seedlings and axillary branches that arise from buds initiated during cold treatment, which remain vegetative. We conclude that the duration of vernalization in A. alpina differentially regulates PEP1 in the inflorescence and axillary branches. PEP1 has a dual role regulating meristem fate; it prevents meristems from flowering and antagonizes inflorescence development after vernalization.