Auxin and gibberellin signaling cross-talk promotes hypocotyl xylem expansion and cambium homeostasis
© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissionsoup.com.
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 72(2021), 10 vom: 04. Mai, Seite 3647-3660 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Arabidopsis hypocotyl DELLA KNAT1/BP auxin responsive cambium fiber gibberellins phloem mehr... |
| Zusammenfassung: | © The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissionsoup.com. During secondary growth, the thickening of plant organs, wood (xylem) and bast (phloem) is continuously produced by the vascular cambium. In Arabidopsis hypocotyl and root, we can distinguish two phases of secondary growth based on cell morphology and production rate. The first phase, in which xylem and phloem are equally produced, precedes the xylem expansion phase in which xylem formation is enhanced and xylem fibers differentiate. It is known that gibberellins (GA) trigger this developmental transition via degradation of DELLA proteins and that the cambium master regulator BREVIPEDICELLUS/KNAT1 (BP/KNAT1) and receptor like kinases ERECTA and ERL1 regulate this process downstream of GA. However, our understanding of the regulatory network underlying GA-mediated secondary growth is still limited. Here, we demonstrate that DELLA-mediated xylem expansion in Arabidopsis hypocotyl is mainly achieved through DELLA family members RGA and GAI, which promote cambium senescence. We further show that AUXIN RESPONSE FACTOR 6 (ARF6) and ARF8, which physically interact with DELLAs, specifically repress phloem proliferation and induce cambium senescence during the xylem expansion phase. Moreover, the inactivation of BP in arf6 arf8 background revealed an essential role for ARF6 and ARF8 in cambium establishment and maintenance. Overall, our results shed light on a pivotal hormone cross-talk between GA and auxin in the context of plant secondary growth |
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| Beschreibung: | Date Completed 21.05.2021 Date Revised 31.05.2022 published: Print CommentIn: J Exp Bot. 2021 May 4;72(10):3489-3492. - PMID 33948652 Citation Status MEDLINE |
| ISSN: | 1460-2431 |
| DOI: | 10.1093/jxb/erab089 |