From RiceWiki
Jump to: navigation, search

The rice Os02g0491300 was reported as MTR1 in 2012 [1] by researchers from China.

Annotated Information

Gene Symbol

  • Os02g0491300 <=> OsMTR1,MTR1
Figure 1. Phenotypic Analysis of mtr1 Anthers.[1].


  • MICROSPORE AND TAPETUM REGULATOR1 (MTR1) is a rice fascilin glycoprotein protein.
  • MTR1 may act as an extracellular adhesion molecule in male reproductive development by regulating the cell-to-cell communication between reproductive cells and their adjacent somatic cells.
  • MTR1 can controll the development of sporophytic and reproductive cells in rice (Oryza sativa).
  • MTR1 is an essential gene for programmed tapetal cell fate and pollen formation in rice.
  • MTR1 is required for both the development of the diploid anther wall cells and maturation of the postmeiotic haploid microspores.
  • MTR1 effect the deposition of sporopollenin precursors on the surface.

Gene Structure

  • MTR1 locus was located on chromosome 2 between two InDel markers, TH239 and TH234. The MTR1 transcript is approximately 2 kb in length and contains a 1,752 bp coding sequence without any intron, a 55 bp 5' untranslated region (UTR) and a 193 bp 3' UTR.
  • The predicted MTR1 protein is 583 amino acids long and contains a putative N-terminal signal peptide; two fasciclin domains (amino acids 257–356 and 435–535); and two potential N-glycosylation sites (amino acids 433 and 554).
Figure 6. Map-Based Cloning analysis of MTR1[1].

Mutation and Phenotype

  • mtr1 shows normal vegetative and nonreproductive floral organ development, but has smaller and pale-yellow anthers that fail to produce viable pollen grains (Figures S1A–S1F available online; Figures 1A and 1B).
  • All the F1 progeny from the backcross between wild-type and mtr1 displayed the wide-type phenotype, and the F 2 progeny yielded a segregation of 481 wild-type and 147 mutant plants (c 2 = 0.85,p > 0.05), suggesting a monofactorial recessive inheritance of the mutation.
  • To characterize the defects of anther development in mtr1, researchers performed 4 0 ,6-diamidino-2-phenylindole (DAPI) staining of microspores.
  1. At stage 8b of anther development, mtr1 produced normal tetrads just like the wild-type (Figures 1C and 1D). However, at stages 9 and 10, after the microspores were released from the tetrad, mtr1 microspores expanded much more slowly than those of the wild-type (Figures 1E–1H).
  2. At later stages, each wild-type microspore underwent mitosis, gener- ating the mature trinucleate pollen grain that contains two smaller sperm nuclei and a larger vegetative nucleus (Figures 1I and 1K).
  3. By contrast, mtr1 microspores continued to show slow development, did not seem to go through mitosis, and were eventually aborted (Figures 1J and 1L).

Labs working on this gene

  • State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology Center, Key Laboratory of Genetics & Development and
  • Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA


  1. 1.0 1.1 1.2 Tan H, Liang W, Hu J, Zhang D. MTR1 encodes a secretory fasciclin glycoprotein required for male reproductive development in rice. Dev Cell. 2012 Jun 12;22(6):1127-37. doi: 10.1016/j.devcel.2012.04.011. PubMed PMID: 22698279.

Structured Information