Proteomic analysis of reserve proteins in commercial rice cultivars

Abstract

| INTRODUC TI ONOryza sativa L. is one of the main food commodity, and nearly half of the world population depend on this culture for daily nutrition.Rice is cultivated mainly in Asia, but in Europe, Italy is the largest producer of rice with an area of 234.133 ha and a production of over 1.5 M ton, representing about 39% and 36% of the harvest area and of the European production, respectively (Faostat, December 2018). Both japonica and indica varieties are cultivated and, some japonica cultivars, such as Arborio, Carnaroli, Vialone nano, are present only in Italy. Rice consumption is steadily rising in western countries, with the adoption of new nutritional styles and the avoidance of gluten. Rice grains contain a low amount of proteins (7%-10%) most of which are storage proteins represented by glutelins, prolamins (poor in lysine), and a lower amount of albumins and globulins. The aminoacidic composition of seed storage proteins (SSP) contributes to the nutritional quality of rice seeds (Shewry and Halford, 2002). Abstract Rice consumption is rising in western countries with the adoption of new nutritional styles, which require the avoidance of gluten. Nevertheless, there are reports of rice allergic reactions. Rice grains contain a low amount of proteins most of which are storage proteins represented by glutelins, prolamins, albumins, and globulins. Some of these proteins are seed allergenic proteins as α-amylase/trypsin inhibitor, globulins, β-glyoxylase, and several glutelins. Italy is the major rice producer in Europe, and for this, seed reserve proteins of four Italian rice cultivars were characterized by 2D-GE analysis. Some differentially abundant proteins were identified and classified as allergenic proteins, prompting a further characterization of the genes encoding some of these proteins. In particular, a deletion in the promoter region of the 19 KDa globulin gene has been identified, which may be responsible for the different abundance of the protein in the Karnak cultivar. This polymorphism can be applied for cultivar identification in commercial samples. Seed proteome was characterized by a variable combination of several proteins, which may determine a different allergenic potential. Proteomic and genomic allowed to identify the protein profile of four commercial cultivars and to develop a molecular marker useful for the analysis of commercial products. K E Y W O R D S 2D-GE, allergens, Oryza sativa, seed storage proteins | 1789 GRAZIANO et Al.

Evaluation of using the rice in Mekong Delta for beer making: Nutritional, heat‐resistant, protease‐resistant, and inhibitor properties of proteins

“…Some cases of rice allergic reactions were reported mainly due to the allergenic protein class α‐amylase/trypsin inhibitors (14–16 kDa) classified as albumin, α‐globulin, β‐glyoxylase, and some glutelin (Graziano et al, 2020). With the degradation of these polypeptides, lower molecular weight polypeptides such as 31, 28, 20, and 15 kDa appeared on the gel.…”

“…Another rice protein that is responsible for allergy is α-amylase/ inhibitor (14-16 kDa), classified as albumins, α-globulins, β-glyoxylase, and several glutelins (Graziano et al, 2020). Among the rice allergens that have been reported are expansin (35 kDa)…”

Integrated Genetic and Omics Approaches for the Regulation of Nutritional Activities in Rice (<em>Oryza sativa</em> L.)

“…Many Investigations focusing on seed rice storage protein expression levels and their relationship with nutritional quality have been conducted to better understand protein regulation. Proteomic techniques were utilized to characterize 302 candidate proteins for their biochemical functions such as catalytic and hydrophilic activities, as well as binding affinity in metabolic pathways [81]. Proteome and glycomic analysis of rice chalky grains exposed to high environmental stresses showed the breakdown of starch rather than the synthesis of starch that is responsible for rice chalkiness.…”

Toward Integrated Multi-Omics Intervention: Rice Trait Improvement and Stress Management

“…Particularly, a deletion in the 1000 bp upstream region of the globulin gene has been recognized, probably contributing to the varied abundance of the protein in the Karnak cultivar. This is useful for cultivar identification in commercial samples (Graziano et al, 2020). In another interesting study, three cytochrome P450 homoeologs (Os03g0603100, Os03g0568400, and GL3.2) and OsBADH2 were edited with the CRISPR/Cas9 to produce novel rice mutants.…”