SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation

Jintao Li; Yu Zhao; Huangwei Chu; Likai Wang; Yanru Fu; Ping Liu; Narayana Upadhyaya; Chunli Chen; Tongmin Mou; Yuqi Feng; Prakash Kumar; Jian Xu

doi:10.1371/journal.pgen.1005464

SHOEBOX Modulates Root Meristem Size in Rice through Dose-Dependent Effects of Gibberellins on Cell Elongation and Proliferation

PLoS Genet. 2015 Aug 14;11(8):e1005464. doi: 10.1371/journal.pgen.1005464. eCollection 2015 Aug.

Authors

Jintao Li¹, Yu Zhao¹, Huangwei Chu², Likai Wang¹, Yanru Fu¹, Ping Liu³, Narayana Upadhyaya⁴, Chunli Chen¹, Tongmin Mou¹, Yuqi Feng³, Prakash Kumar², Jian Xu²

Affiliations

¹ National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.
² Department of Biological Sciences and NUS Centre for BioImaging Sciences, National University of Singapore, Singapore.
³ Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan, China.
⁴ Plant Industry, Commonwealth Scientific and Industrial Research Organization, Canberra, Australia.

Abstract

Little is known about how the size of meristem cells is regulated and whether it participates in the control of meristem size in plants. Here, we report our findings on shoebox (shb), a mild gibberellin (GA) deficient rice mutant that has a short root meristem size. Quantitative analysis of cortical cell length and number indicates that shb has shorter, rather than fewer, cells in the root meristem until around the fifth day after sowing, from which the number of cortical cells is also reduced. These defects can be either corrected by exogenous application of bioactive GA or induced in wild-type roots by a dose-dependent inhibitory effect of paclobutrazol on GA biosynthesis, suggesting that GA deficiency is the primary cause of shb mutant phenotypes. SHB encodes an AP2/ERF transcription factor that directly activates transcription of the GA biosynthesis gene KS1. Thus, root meristem size in rice is modulated by SHB-mediated GA biosynthesis that regulates the elongation and proliferation of meristem cells in a developmental stage-specific manner.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Base Sequence
Binding Sites
Cell Proliferation
Cell Shape
Gene Expression Regulation, Developmental
Gene Expression Regulation, Plant
Gibberellins / physiology*
Meristem / cytology
Meristem / growth & development*
Meristem / metabolism
Oryza / cytology
Oryza / growth & development*
Oryza / metabolism
Plant Growth Regulators / physiology
Plant Proteins / physiology*
Plant Roots / cytology
Plant Roots / growth & development
Plant Roots / metabolism
Transcription Factor AP-2 / physiology*

Substances

Gibberellins
Plant Growth Regulators
Plant Proteins
Transcription Factor AP-2

Grants and funding

This work was funded by National Natural Science Foundation of China (30700421; 31070327; 91017013, 91217309), Huazhong Agricultural University and National Key Laboratory of Crop Genetic Improvement; and was supported by NWO VENI grant (863-08-001), AcRF Tier 2 grant (MOE2009-T2-1-060) from the Ministry of Education of Singapore and National Research Foundation Singapore under its Competitive Research Programme (CRP Award No. NRF2010NRF-CRP002-018). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.