Chinese Bulletin of Botany ›› 2019, Vol. 54 ›› Issue (3): 293-295.DOI: 10.11983/CBB19063

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A TIR1-independent Auxin Signaling Module

Kongqin Hu,Zhaojun Ding()   

  1. Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, College of Life Sciences, Shandong University, Qingdao 266237, China
  • Received:2019-03-29 Accepted:2019-03-31 Online:2019-05-01 Published:2019-05-20
  • Contact: Zhaojun Ding

Abstract: The most well established auxin signaling pathway is initiated from transport inhibitor response (TIR1)-mediated perception and degradation of Aux/IAAs, eventually leads to depression of auxin response factors (ARFs). A recent study from the Tongda Xu lab showed that high levels of auxin induced the cleavage of the plasma membrane localized transmembrane kinase receptor 1 (TMK1). The cleaved TMK1 C-terminus translocated to the nucleus and phosphorylated the nuclear localized non-canonical IAA32/34, which regulate the auxin signaling response by interacting with ARFs. The TMK1-IAA32/34-ARFs module, acting independently from the TIR1-dependent auxin signaling pathway, nicely interprets how the local auxin accumulation modulates asymmetric growth during apical hook development.

Key words: auxin, signal transduction, TMK1