Plant Cytogenetics Laboratory

Nonomura Group

Molecular cytogenetic studies on regulatory mechanisms driving plant reproductive processes

Faculty

NONOMURA, Ken-ichi
Professor

knonomur@nig.ac.jp

researchmap

Harsha　Somashekar

Assistant Professor

harsha.s@nig.ac.jp

 Lab HP

Research Summary

Meiosis is a special cell division that halves the chromosome number for fertilization and stably transmits genetic information to offspring. It also creates genetic diversity through meiotic recombination, which is utilized for the crossbreeding of animals and plants. We aim to elucidate the molecular mechanisms that control plant reproductive development including meiosis.


Furthermore, we support plant researches through preservation, provision, and contract cultivation of Gramineae genetic resources, including wild rice relatives and experimental cultivated rice strains, in use of the plant cultivation facilities in NIG.

Rice AGO4a protein functions in DNA methylation in meiocytes
(A) AGO4a accumulated in male meiocyte nuclei (arrowheads) and associated most to meiosis-specific 24nt phasiRNAs, and second most to 24nt transposable element (TE)-derived siRNAs. (B) A schematic for
isolation of meiocytes. (C) CHH (H=A, T, C) methylation was globally affected by ago4a mutation in microspores, the meiotic products. (Best Papers Award for the 96th Annual Meeting of Genetics Society of Japan)

Selected Publications

  • Harsha Somashekar, Keiko Takanami, Yoselin Benitez-Alfonso, Akane Oishi, Rie Hiratsuka, Ken-Ichi Nonomura. Callose deficiency modulates plasmodesmata frequency and extracellular distance in rice pollen mother and tapetal cells. Annals of Botany. 2024 Dec. 134(6)1013-1026.
  • Manaki Mimura, Seijiro Ono, Harsha Somashekar, Ken-Ichi Nonomura. Impact of protein domains on the MEL2 granule, a cytoplasmic ribonucleoprotein complex maintaining faithful meiosis progression in rice. New Phytologist 2024 Jul. 243 2235-2250.
  • Katsutoshi Tsuda, Akiteru Maeno, Ayako Otake, Kae Kato, Wakana Tanaka, Ken-Ichiro Hibara, and Ken-Ichi Nonomura. YABBY and diverged KNOX1 genes shape nodes and internodes in the stem. Sciencs. 2024 Jun. 384(6701)1241-1247.
  • Harsha Somashekar , Manaki Mimura , Katsutoshi Tsuda , Ken-Ichi Nonomura. Rice GLUCAN SYNTHASE-LIKE5 promotes anther callose deposition to maintain meiosis initiation and progression. Plant Physiology 2023 Jan2. 191(1)400-413.