Nitrogen depletion and small R3-MYB transcription factors affecting anthocyanin accumulation in Arabidopsis leaves
Nitrogen depletion and small R3-MYB transcription factors affecting anthocyanin accumulation in Arabidopsis leaves
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DOI：
10.1016/j.phytochem.2013.12.006
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发表时间：
2014-02-01
期刊：
影响因子：
3.8
通讯作者：
Lillo, Cathrine
中科院分区：
文献类型：
--
作者：
Nemie-Feyissa, Dugassa;Olafsdottir, Solveig Margret;Lillo, Cathrine
由R2R3-MYB、bHLH和WD40蛋白组成的三元复合物（MBW复合物）调节植物毛状体的形成和花青素的合成。小的R3-MYBs与MBW复合物相互作用，施加负反馈，从而参与表皮细胞命运的调节，例如叶片的毛状体数量和聚类。在拟南芥中，bHLH转录因子GL3在调节毛状体形成的MBW复合体以及氮耗尽诱导的MBW复合体和促进花青素形成中起重要作用。较小的r3 - myb: CPC， TRY， ETCI, ETC2, ETO/CPL3, TC1.1, MYBL2，都已知与GL3相互作用。我们在这里研究了在缺氮条件下拟南芥莲座期植株叶片中的这些R3-MYBs，以研究在正常（自养）生长条件下，这些小MYBs是否会干扰植物花青素的积累。CPC的表达在氮耗尽后增加了两倍，而ETC3/CPL3的表达几乎增加了一个数量级（9倍）。敲除ETC3/CPL3不影响花青素的积累，但结果表明ETO/CPL3是一个硝酸盐调控基因，并且可能参与硝酸盐状态信号传导和根发育。其他测试的R3-MYBs不受氮消耗的显著影响。综上所述，在氮饥饿条件下，只有CPC表达增加，并对花环叶片花青素积累有明显的负反馈作用。(C) 2013 Elsevier Ltd.版权所有。
Ternary complexes consisting of a R2R3-MYB, a bHLH and a WD40 protein (MBW complexes) regulate trichome formation and anthocyanin synthesis in plants. Small R3-MYBs interact with the MBW complexes to exert a negative feedback, and thereby participate in regulation of epidermal cell fate, for example trichome numbers and clustering in leaves. In Arabidopsis thaliana, GL3, a bHLH transcription factor, is important in the MBW complex regulating trichome formation as well as in the MBW complex induced by nitrogen depletion and promoting anthocyanin formation. The small R3-MYBs: CPC, TRY, ETCI, ETC2, ETO/CPL3, TC1.1, MYBL2, are all known to interact with GL3. We here investigated these R3-MYBs in leaves of Arabidopsis rosette stage plants under nitrogen depletion to examine if the small MYBs would interfere with anthocyanin accumulation in plants under normal (autotrophic) growth conditions. CPC expression was enhanced two-fold in response to nitrogen depletion, and ETC3/CPL3 expression was enhanced by almost an order of magnitude (9x). Knockout of ETC3/CPL3 did not influence anthocyanin accumulation, but the results establish ETO/CPL3 as a nitrate regulated gene and a putative candidate for being involved in nitrate status signaling and root development. Other R3-MYBs tested were not significantly influenced by nitrogen depletion. In conclusion, only CPC expression increased and clearly exerted a negative feedback on anthocyanin accumulation during nitrogen starvation in rosette leaves. (C) 2013 Elsevier Ltd. All rights reserved.