Os08g0137100

The rice Os08g0137100 was reported as OsFIE2 by researchers from Australia, Korea and America in 2009, 2012 and 2013, respectively.

Annotated Information

Function

Figure 1. Wild-type lines VS. OsFIE2 Overexpression lines (from reference).

• As a member of polycomb group genes, OsFIE2 could control seed development and grain filling by regulating multiple levels of targets including transcription regulators as well as metabolic pathway genes.The functional analysis of OsFIE2 made by Jong-Kuk Na in 2012, indicated that this gene played an important role in cotyledon, probably by forming the PRC2 suppressive complex.
  
• Over expression of OsFIE2 produced bigger seeds than the wild type. While the reduction of OsFIE2 expression led to smaller seeds, partially filled seeds, and partial loss of seed dormancy.

Wild Type & Mutations

• Transgenic (overexpression) analysis through Arabidopsis made by Jong-Kuk Na et al. in 2012 showed that during the late seedling stage, OsFIE2 transgenic plants exhibited wider leaves and petioles than the wild type. They can also produced bigger seeds than the wild-type lines (Figure 1).
  
• The increased growth phenotype of OsFIE2 transgenic plants only occured during the first 1–2 weeks after germination. Transgenic plants grew no faster than the wild type any more after the late seedling stage.
  
  

Figure 2. OsFIE2-RNAi lines VS. WT (from reference).

• Transgenic (RNAi) analysis through rice made by Babi Ramesh Reddy Nallamilli et al. showed a substantially reduced ratio of mature and fully filled seeds in RNAi plants .
  
• It can be found in the Figure 2 that panicles of RNAi plants containmore partially filled seeds and less filled seeds when compared to wild type panicles. In the partially filled seeds of RNAi lines, defective shrunken endosperm tissue could be observed).

Figure 3. Expression pattern of OsFIE2 (from reference).

Expression Pattern

• The gene expression analysis made by Jong-Kuk Na et al. in 2012 showed that OsFIE2 was expressed in all tissues, but exhibited higher expression in stem and leaf. And the gene expression analysis made by Babi Ramesh Reddy Nallamilli et al. in 2013 further showed that OsFIE2 gene was highly expressed in anthers while the expression of its partener gene OsFIE1 was not detected in anthers.

Evolution

• The previous study made by Ming Luo et al. in 2009 reported that there are two ESC homologs in Oryza sativa Japonica : OsFIE1 (Os08g0137250) and OsFIE2 (Os08g0137100). Separated by one unrelated gene, these two genes are located close to each other on chromosome 8. While in Arabidposis, only one ESC homolog gene was found OsFIE2 shares 72% identity with OsFIE1.
• Further gene structure analysis made by Ming Luo et al. in 2009 showed that all the ESC proteins in rice, maize, Arabidopsis, and Drosophila contained seven conserved WD40 repeats.

Labs working on this gene

• CSIRO Plant Industry, GPO BOX 1600, ACT 2601, Australia;
• Bio-resources, National Academy of Agricultural Science, RDA, Suwon 441-701, Republic of Korea;
• Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, Mississippi, United States of America;
• Department of Computer Science and Engineering, Mississippi State University, Mississippi State, Mississippi, United States of America;
• Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, Mississippi, United States of America.