A differentially regulated AP2/ERF transcription factor gene cluster acts downstream of a MAP kinase cascade to modulate terpenoid indole alkaloid biosynthesis in Catharanthus roseus

作者：Paul Priyanka; Singh Sanjay K; Patra Barunava; Sui Xueyi; Pattanaik Sitakanta; Yuan Ling

来源：NEW PHYTOLOGIST, 2017, 213(3): 1107-1123.

DOI：10.1111/nph.14252

<jats:title>Summary</jats:title><jats:p>
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<jats:list-item><jats:p><jats:italic>Catharanthus roseus</jats:italic> produces bioactive terpenoid indole alkaloids (<jats:styled-content style="fixed-case">TIA</jats:styled-content>s), including the chemotherapeutics, vincristine and vinblastine. Transcriptional regulation of <jats:styled-content style="fixed-case">TIA</jats:styled-content> biosynthesis is not fully understood.</jats:p></jats:list-item>

<jats:list-item><jats:p>The jasmonic acid (<jats:styled-content style="fixed-case">JA</jats:styled-content>)‐responsive <jats:styled-content style="fixed-case">AP</jats:styled-content>2/<jats:styled-content style="fixed-case">ERF</jats:styled-content> transcription factor (<jats:styled-content style="fixed-case">TF</jats:styled-content>), <jats:styled-content style="fixed-case">ORCA</jats:styled-content>3, and its regulator, Cr<jats:styled-content style="fixed-case">MYC</jats:styled-content>2, play key roles in <jats:styled-content style="fixed-case">TIA</jats:styled-content> biosynthesis. <jats:styled-content style="fixed-case">ORCA</jats:styled-content>3 forms a physical cluster with two uncharacterized <jats:styled-content style="fixed-case">AP</jats:styled-content>2/<jats:styled-content style="fixed-case">ERF</jats:styled-content>s, <jats:styled-content style="fixed-case">ORCA</jats:styled-content>4 and 5. Here, we report that (1) the <jats:styled-content style="fixed-case">ORCA</jats:styled-content> gene cluster is differentially regulated; (2) <jats:styled-content style="fixed-case">ORCA</jats:styled-content>4, while overlapping functionally with <jats:styled-content style="fixed-case">ORCA</jats:styled-content>3, modulates an additional set of <jats:styled-content style="fixed-case">TIA</jats:styled-content> genes. Unlike <jats:styled-content style="fixed-case">ORCA</jats:styled-content>3, <jats:italic><jats:styled-content style="fixed-case">ORCA</jats:styled-content>4</jats:italic> overexpression resulted in dramatic increase of <jats:styled-content style="fixed-case">TIA</jats:styled-content> accumulation in <jats:italic>C. roseus</jats:italic> hairy roots. In addition, Cr<jats:styled-content style="fixed-case">MYC</jats:styled-content>2 is capable of activating <jats:italic><jats:styled-content style="fixed-case">ORCA</jats:styled-content>3</jats:italic> and co‐regulating <jats:styled-content style="fixed-case">TIA</jats:styled-content> pathway genes concomitantly with <jats:styled-content style="fixed-case">ORCA</jats:styled-content>3.</jats:p></jats:list-item>

<jats:list-item><jats:p>The <jats:styled-content style="fixed-case">ORCA</jats:styled-content> gene cluster and Cr<jats:styled-content style="fixed-case">MYC</jats:styled-content>2 act downstream of a <jats:styled-content style="fixed-case">MAP</jats:styled-content> kinase cascade that includes a previously uncharacterized <jats:styled-content style="fixed-case">MAP</jats:styled-content> kinase kinase, Cr<jats:styled-content style="fixed-case">MAPKK</jats:styled-content>1. Overexpression of <jats:italic>Cr<jats:styled-content style="fixed-case">MAPKK</jats:styled-content>1</jats:italic> in <jats:italic>C. roseus</jats:italic> hairy roots upregulated <jats:styled-content style="fixed-case">TIA</jats:styled-content> pathways genes and increased <jats:styled-content style="fixed-case">TIA</jats:styled-content> accumulation.</jats:p></jats:list-item>

<jats:list-item><jats:p>This work provides detailed characterization of a <jats:styled-content style="fixed-case">TF</jats:styled-content> gene cluster and advances our understanding of the transcriptional and post‐translational regulatory mechanisms that govern <jats:styled-content style="fixed-case">TIA</jats:styled-content> biosynthesis in <jats:italic>C. roseus</jats:italic>.</jats:p></jats:list-item>
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• 出版日期2017-2