The rice Os02g0491300 was reported as MTR1 in 2012  by researchers from China.
- Os02g0491300 <=> OsMTR1,MTR1
- 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.
- 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).
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.
- 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).
- 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).
- 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
- 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.