Polar vacuolar distribution is essential for accurate asymmetric division of Arabidopsis zygotes

Yusuke Kimata, Takehide Kato, Takumi Higaki, Daisuke Kurihara, Tomomi Yamada, Shoji Segami, Miyo Terao Morita, Masayoshi Maeshima, Seiichiro Hasezawa, Tetsuya Higashiyama, Masao Tasaka, Minako Ueda

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)

Abstract

In most flowering plants, the asymmetric cell division of the zygote is the initial step in establishing the apical-basal axis of the mature plant. The zygote is polarized, possessing the nucleus at the apical tip and large vacuoles at the basal end. Despite their known polar localization, whether the positioning of the vacuoles and the nucleus is coordinated and what the role of the vacuole is in the asymmetric zygotic division remain elusive. In the present study, we utilized a live-cell imaging system to visualize the dynamics of vacuoles during the entire process of zygote polarization in Arabidopsis. Image analysis revealed that the vacuoles formed tubular strands around the apically migrating nucleus. They gradually accumulated at the basal region and filled the space, resulting in asymmetric distribution in the mature zygote. To assess the role of vacuoles in the zygote, we screened various vacuole mutants and identified that shoot gravitropism2 (sgr2), in which the vacuolar structural change was impaired, failed to form tubular vacuoles and to polarly distribute the vacuole. In sgr2, large vacuoles occupied the apical tip and thus nuclear migration was blocked, resulting in a more symmetric zygotic division. We further observed that tubular vacuole formation and asymmetric vacuolar distribution both depended on the longitudinal array of actin filaments. Overall, our results show that vacuolar dynamics is crucial not only for the polar distribution along actin filaments but also for adequate nuclear positioning, and consequently zygote-division asymmetry.

Original languageEnglish
Pages (from-to)2338-2343
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume116
Issue number6
DOIs
Publication statusPublished - 2019 Feb 5
Externally publishedYes

Keywords

  • Apical-basal axis
  • Arabidopsis thaliana
  • Live-cell imaging
  • Vacuole
  • Zygote

ASJC Scopus subject areas

  • General

Fingerprint

Dive into the research topics of 'Polar vacuolar distribution is essential for accurate asymmetric division of Arabidopsis zygotes'. Together they form a unique fingerprint.

Cite this