A Role for the Cysteine-Rich 10 kDa Prolamin in Protein Body I Formation in Rice

The rice prolamins consist of cysteine-rich 10 kDa (CysR10), 14 kDa (CysR14) and 16 kDa (CysR16) molecular species and a cysteine-poor 13 kDa (CysP13) polypeptide. These storage proteins form protein bodies (PBs) composed of single spherical intracisternal inclusions assembled within the lumen of the rough endoplasmic reticulum. Immunofluorescence and immunoelectron microscopy demonstrated that CysR10 and CysP13 were asymmetrically distributed within the PBs, with the former concentrated at the electron-dense center core region and the latter distributed mainly to the electron-lucent peripheral region. These results together with temporal expression data showed that the formation of prolamin-containing PB-I in the wild-type endosperm was initiated by the accumulation of CysR10 to form the center core. In mutants deficient for cysteine-rich prolamins, the typical PB-I structures containing the electron-dense center core were not observed, and instead were replaced by irregularly shaped, electron-lucent, hypertrophied PBs. Similar, deformed PBs were observed in a CysR10 RNA interference plant line. These results suggest that CysR10, through its formation of the central core and its possible interaction with other cysteine-rich prolamins, is required for tight packaging of the proteins into a compact spherical structure

mRNA Localization in Plant Cells

Localization of mRNAs at the subcellular level is an essential mechanism for specific protein targeting and local control of protein synthesis in both eukaryotes and bacteria. While mRNA localization is well documented in metazoans, somatic cells, and microorganisms, only a handful of well-defined mRNA localization examples have been reported in vascular plants and algae. This review summarizes the function and mechanism of mRNA localization and highlights recent studies of mRNA localization in vascular plants. While the emphasis focuses on storage protein mRNA localization in rice endosperm cells, information on targeting of RNAs to organelles (chloroplasts and mitochondria) and plasmodesmata is also discussed

Distinct Roles of Protein Disulfide Isomerase and P5 Sulfhydryl Oxidoreductases in Multiple Pathways for Oxidation of Structurally Diverse Storage Proteins in Rice[W][OA]

This work examines the localization and functions of two protein disulfide isomerase family oxidoreductases in formation of protein storage bodies in rice endosperm, finding that the two have nonoverlapping localizations, activities, and biological functions

Genetic Diversity of Soybean Genotypes revealed by Agro–morphological and SSR markers

Increasing the diversity of the soybean germplasm base could introduce new genes affecting agronomic traits. In this study, we demonstrated the differences of genetic diversity level among 24 soybean genotypes and adapt an augmented design to screen and select the superior entries among 24 soybean germlasm and to calculate similarity parameters. Likewise, to elucidate the relationships based on molecular markers among new promising lines and introduced genotypes with improved Egyptian commercial cultivars using SSR markers, to use this information in future breeding programs. The results exhibited significant differences among the tested genotypes for all studied characters. This provides evidence for the possibility to carry out a sufficient selection program on the basis of these traits using the studied genotypes. Thirteen out 14 SSR primer pairs amplify polymorphic SSRs from all of these genotypes, a total of 42 alleles were produced. The polymorphic information content (PIC) among genotypes varied from 0.55 (satt001) to 0.88 (satt173) with 2 and 5 alleles respectively. However, Satt005 produced only one monomorphic band. The used SSR primer pairs successfully distinguished most of soybean genotypes, with the exception of a pair of closely related breeding lines from the same cross. The genetic relationships among genotypes based agro–morphological analysis not completely agreed with known pedigrees. However, phylogenetic tree based on SSR confirmed the separation of soybean genotypes into six clusters and were more clearly separated. These results suggest that SSR markers are efficient for measuring genetic diversity and relatedness as well as identifying varieties of soybeans