BMB Reports 2018; 51(11): 547-548
In vivo action of RNA G-quadruplex in phloem development
Hyunwoo Cho1,#, Hyun Seob Cho2,#, and Ildoo Hwang2,*
1Centre for Organismal Studies, Heidelberg University, Heidelberg 69120, Germany, 2Department of Life Sciences, POSTECH Biotech Center, Pohang University of Science and Technology, Pohang 37673, Korea
Correspondence to: *Corresponding author. E-mail:
Received: October 15, 2018; Published online: November 30, 2018.
© Korean Society for Biochemistry and Molecular Biology. All rights reserved.

cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Phloem network integrates cellular energy status into post-embryonic growth, and development by tight regulation of carbon allocation. Phloem development involves complicated coordination of cell fate determination, cell division, and terminal differentiation into sieve elements (SEs), functional conduit. All of these processes must be tightly coordinated, for optimization of systemic connection between source supplies and sink demands throughout plant life cycle, that has substantial impact on crop productivity. Despite its pivotal role, surprisingly, regulatory mechanisms underlying phloem development have just begun to be explored, and we recently identified a novel translational regulatory network involving RNA G-quadruplex and a zinc-finger protein, JULGI, for phloem development. From this perspective, we further discuss the role of RNA G-quadruplex on post-transcriptional control of phloem regulators, as a potential interface integrating spatial information for asymmetric cell division, and phloem development.

Keywords: Phloem, RNA G-quadruplex, SMXL, Sucrose, Zinc-finger protein

This study was supported by a grant from the Next-Generation BioGreen 21 Program (SSAC, grant#: PJ013423012018), Rural Development Administration, Republic of Korea.

APL: altered phloem development
BAM3: barely any meristem 3
CLE: clavata3/embryo surrounding region
NEN: nac45/86-dependent exonuclease-domain protein
SE: sieve element
SMXL: supressor of max2-like
Fig. 1. Regulation of phloem development by SMXL4/5-JULGI module. Unstructured G-quadruplex of SMXL4/5 leads translation, and accumulation of SMXL4/5 proteins promotes phloem differentiation. Conversely, formation of G-quadruplex in SMXL4/5 by JULGI suppresses translation, and inhibits phloem differentiation independent of other peptide- or transcription factor-mediated regulation. Blue arrows indicate potential movement of JUL-SMXL4/5 complex in SE. CC, companion cell; SE, sieve element.

This Article

Cited By Articles
  • CrossRef (0)

Funding Information

Social Network Service