Reina Komiya, Ph.D.

Science and Technology Associate
Science and Technology Group


Successful sexual reproduction in flowering plants depends on the appropriate germ cell differentiation. In plant reproductive stages, germ cell differentiation is initiated after the floral transition and the completion of flower organ development. The molecular mechanism of germ cell development in plants remains unknown, though there are many publications about “Florigen”, “Meiosis” and “Double fertilization”. I study the reproductive stages around germ cell differentiation to reveal molecular mechanisms of male and female germ cell development in rice.


non-coding RNA, Germ cell, Reproduction, Rice



1. Reproductive mechanism including long intergenic non-coding RNAs (lincRNA) in rice

  Large numbers of endogenous non-coding RNAs (ncRNAs) play important roles at various developmental stages in most organisms. There are two major classes of ncRNAs, small RNAs and large ncRNAs.

  I have detected over 700 lincRNAs, which are transcribed in rice inflorescences specifically around germ cell developmental stages. These lincRNAs are the precursors of 21-nucleotide small RNAs, which are required for both miR2118 cleavage and Dicer protein processing (Komiya et al., 2014; Figs1, 2).

-  Functional analysis of reproductive-specific lincRNAs and miR2118

-  Transcriptional regulatory mechanism of reproductive-specific lincRNAs through epigenetics

-  Translational regulation of these lincRNAs

-  Bio-imaging of these lincRNAs in pollen mother cells in rice

2. Chromatin regulation of germ cells in rice

  What differences exist between somatic cells and germ cells prior to meiosis? How does germ cell initiation occur in plants? I’m specifically interested in the chromatin dynamics of premeiotic germ cells in plants. 

-  Genome dynamics between somatic cells and germ cells in rice

-  Functional analysis of a chromatin-regulated factor 1 using mutant analysis and  

 Chromatin-immunoprecipitation (IP)


Komiya, R. Biogenesis of diverse plant phasiRNAs involves an miRNA-trigger and Dicer-processing. Journal of Plant Research. 30,17-23 (2016).


小宮怜奈. 植物「コサプレッション」が先駆けとなったRNAi.

実験医学 増刊 ノンコーディングRNAテキストブック, 33, 26-27 (2015).


Komiya, R., Ohyanagi, H., Niihama, M., Watanabe, T., Nakano, M., Kurata, N. and Nonomura, K. I. MEL1, a germ specific Argonaute, binds to phasiRNAs derived from lincRNAs. The Plant Journal. 78, 385-397 (2014).

Komiya, R and Nonomura, K.I. Isolation and bioinformatic analyses of small RNAs interacting with germ-cell specific Argonaute in rice. Methods in Molecular Biology. 1093, 235-245 (2014).

Shirasawa, S., Kifuji, Y., Komiya, R., Kitashiba, H., Nishimura, M. and Nishio, T.  Identification of a single nucleotide deletion of OsDFR2A causing frame shift in a genic male sterile mutant of rice and its possible application to F1 hybrid breeding. Molecular Breeding. 31, 805-814 (2013).

高橋有, 山内卓樹, 角井宏行, 寺内良平, 大柳一, 小宮怜奈, 宮武宏治, 内藤健. 次世代の遺伝学と育種. 育種学研究. 15, 115-121 (2013).

Komiya, R., Yokoi, S. and Shimamoto, K. A gene network for long-day flowering activates RFT1 encoding a mobile flowering signal in rice. Development. 136, 3443-3450 (2009).

Komiya, R., Ikegami, A., Tamaki, S., Yokoi, S. and Shimamoto, K. Hd3a and RFT1 are essential for flowering in rice. Development. 135, 767-774 (2008).

Komiya, R. and Shimamoto, K. Genetic and epigenetic regulation of flowering in rice. Plant Biotechnology. 25, 279-284 (2008).

Tuji, H., Tamaki, S., Komiya, R. and Shimamoto, K. Florigen and the photoperiodic control of flowering in rice. Rice. 1, 25-35 (2008).



Address: 1919-1 Tancha, Onna-son, Okinawa, 904-0495 Japan
Phone: +81-(0)98-966-1569
FAX:  +81-(0)98-966-1064
E-mail: reina.komiya at

Left:  A reproduction-specific gene is damaged in rice, resulting in no seed development.

Right:  In wild-type rice, there are many seeds.