Os01g0179400

From RiceWiki
Jump to: navigation, search

The rice Os01g0179400 was reported as ssg4 in 2014 [1] by researchers from China.

Annotated Information

Fig. 1.Enlarged SGs of mature endosperm in the ssg4 mutant.[1].

Gene Symbol

  • Os01g0179400 <=> ssg4,SSG4,OsSSG4

Function

  • SSG4 encodes a protein that contains 2,135 amino acid residues and an amino-terminal amyloplast-targeted sequence.
  • SSG4 contains a domain of unknown function490 that is conserved from bacteria to higher plants.
  • SSG4 is a novel protein that influences the size of SGs. SSG4 will be a useful molecular tool for future starch breeding and biotechnologyria.

Phenotypic analysis

  • The chalkiness of seeds was a distinguishing pheno- type of ssg4 grains when compared with wild-type grains of cv Nipponbare (Fig. 1, A–D). Seed size was slightly smaller in ssg4 than in cv Nipponbare, especially with respect to seed width and depth (Fig. 1E). The iodine-stained thin sections of mature endosperm clearly showed enlarged SGs in ssg4 endosperms (Fig. 1, F–I).
  • Quantification of the areas occupied by SGs in the thin sections showed that SGs were approximately 6-fold larger in ssg4 than in cv Nipponbare (Fig. 1J).
  • The SG sizes of SSG4SSG4ssg4 and cv Nipponbare seeds did not significantly differ, whereas the SG sizes of the SSG4ssg4ssg4 seeds were slightly larger than those of cv Nipponbare (Fig. 1J). This indicated that two wild-type alleles supplied from the female gametophyte were sufficient for the formation of normal-sized SGs, whereas one copy of the SSG4 allele supplied by the sperm was functional but not sufficient for the formation of normal-sized SGs.
  • The researchers next examined starch accumulation in ssg4 grains. The total amount of starch was lower in ssg4 seeds than in wild-type seeds (Fig. 1K). * No significant difference in the gelatinization properties of ssg4 starch compared with wild-type starch was observed; therefore, the structural properties of starch were similar in ssg4 and cv Nipponbare.

Expression

  • The expression patterns of SSG4 in various tissues of different developmental stages were investigated using real-time quantitative PCR by three different sets of primers
  • Real-time quantitative PCR showed that SSG4 was expressed in all tissues examined in both cv Nipponbare and ssg4. This suggests that SSG4 is needed at all developmental stages.

Subcellular localization

  • Subcellular localization analysis demonstrated that SSG4 was mainly localized in stroma of chloroplasts.

You can also add sub-section(s) at will.

Labs working on this gene

  • Institute of Plant Science and Resources, Okayama University, Kurashiki 710–0046, Japan
  • RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa 230–0045, Japan
  • Department of Biological Production, Akita Prefectural University, Akita 010–0195, Japan
  • Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba 305–8602, Japan

References

  1. 1.0 1.1 Matsushima R, Maekawa M, Kusano M, Kondo H, Fujita N, Kawagoe Y, Sakamoto W. Amyloplast-localized SUBSTANDARD STARCH GRAIN4 protein influences the size of starch grains in rice endosperm. Plant Physiol. 2014 Feb;164(2):623-36. doi: 10.1104/pp.113.229591. Epub 2013 Dec 13. PubMed PMID: 24335509; PubMed Central PMCID: PMC3912094.

Structured Information