The nuclear localization signal is required for the function of squamosa promoter binding protein-like gene 9 to promote vegetative phase change in Arabidopsis

  • Hui Zhang
  • Lu Zhang
  • Junyou Han
  • Zhiyuan Qian
  • Bingying Zhou
  • Yunmin XuEmail author
  • Gang WuEmail author


Key message

A mutation in the nuclear localization signal of squamosa promoter binding like-protein 9 (SPL9) delays vegetative phase change by disrupting its nuclear localization.


The juvenile-to-adult phase transition is a critical developmental process in plant development, and it is regulated by a decrease in miR156/157 and a corresponding increase in their targets, squamosa promoter binding protein-like (SPL) genes. SPL proteins contain a conserved SBP domain with putative nuclear localization signals (NLSs) at their C-terminals. Some SPLs promote vegetative phase change by promoting miR172 expression, but the function of nuclear localization signals in those SPLs remains unknown. Here, we identified a loss-of-function mutant, which we named del6, with delayed vegetative phase change phenotypes in a forward genetic screen. Map-based cloning, the whole genome resequencing, and allelic complementation test demonstrate that a G-to-A substitution in the SPL9 gene is responsible for the delayed vegetative phase change phenotypes. In del6, the mutation causes a substitution of the glutamine (Gln) for the conserved basic amino acid arginine (Arg) in the NLS of the SBP domain, and disrupts the normal nuclear localization and function of SPL9. Therefore, our work demonstrates that the NLSs in the SBP domain of SPL9 are indispensable for its nuclear localization and normal function in Arabidopsis.


Vegetative phase change SPL9 SBP domain Nuclear localization signals (NLS) 



This work was supported by the National Natural Science Foundation of China (No. 31700249 and No. 31770209).

Author contribution

YX and GW conceived and designed the research, HZ, JH, LZ, ZQ and BZ performed the experiments, YX and GW wrote the manuscript.

Supplementary material

11103_2019_863_MOESM1_ESM.docx (7.5 mb)
Supplementary material 1 (DOCX 7673 kb)


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Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.State Key Laboratory of Subtropical Silviculture, Laboratory of Plant Molecular and Developmental BiologyZhejiang Agriculture and Forestry UniversityHangzhouChina
  2. 2.College of Plant ScienceJilin UniversityChangchunChina

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