Analysis of Active Components and Proteomics of Chinese Wild Rice (Zizania latifolia(Griseb)Turcz) andIndicaRice (Nagina22)

Abstract

The ancient Chinese wild rice (Zizania latifolia (Griseb) Turcz) (CWR) has valuable biological and medicinal functions. To assess the advantages lost in modern cultivated rice after domestication, we compared the composition of bioactive compounds and the results of proteomic analysis with those of Indica rice (N22). We used routine methods to determine the protein, total dietary fiber, amino acid, mineral substance, plant secondary metabolites, and amino acid composition of CWR and N22. The protein and mineral contents of CWR were two times that of N22, and the levels of calcium, potassium, magnesium, chromium, iron, and zinc were significantly higher than those of N22 (P < .05). There was ∼7.6 times more dietary fiber in CWR than in N22, but fewer carbohydrates (P < .05). Anthocyanins and chlorophyll were detected in CWR, but were absent from N22. Compared with N22, CWR had 53, 19, and 5.4 times higher (P < .05) levels of saponins, flavonoids, and plant sterols, respectively. The amino acid score of CWR was 66.6, which was significantly higher than N22. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that the main seed proteins of CWR were glutelins, including both acid and alkaline subunits, which were approximately twice those of N22. To investigate the differences in protein profiles between CWR and N22, we conducted two-dimensional electrophoresis (2-DE) analysis of the total proteins in the seeds of the two rice species. 2-DE gels revealed 19 differentially expressed proteins. Information obtained from peptide mass fingerprinting indicates that glutelin precursor caffeoyl coenzyme A (CoA) O-methyltransferase and putative bithoraxoid-like protein can provide good gene sources for improving rice quality.

Morphological Characteristics, Nutrients, and Bioactive Compounds of Zizania latifolia, and Health Benefits of Its Seeds

“…The Z. latifolia seed (Chinese wild rice) is a type of whole grain with high nutritional value; it contains proteins, minerals, and vitamins, as well as bioactive compounds [ 3 , 4 , 28 ]. According to laboratory and population-based studies, Chinese wild rice is a safe and unique tasting food, the consumption of which shows a protective effect [ 24 ].…”

“…In addition, it contains higher amounts of essential amino acids than white rice, barley, and maize [ 30 , 31 ]. The amino acid score of Chinese wild rice is 66.6, which is considerably higher than that of polished Indica rice (51.1) [ 28 ]. The first and second limiting amino acids of Chinese wild rice are originally considered to be threonine and lysine, respectively [ 31 ].…”

Advances in the Biology of Seed and Vegetative Storage Proteins Based on Two-Dimensional Electrophoresis Coupled to Mass Spectrometry

“…This proteomic approach has been addressed in a variety of crops. For instance, wild rice species are a valuable source of genetic resources for improving the nutritional quality of rice by increasing the glutelin content to the detriment of prolamins [ 199 , 200 ]. The comparison of 2-DE-based maps between wild rice species and rice cultivars revealed new subunits and precursors of glutelin in wild rice species [ 199 ].…”

“…Turcz. ) was approximately twice as high as that of the Indica rice cultivar [ 200 ]. Zarkadas et al [ 195 ] also reported great variability among soybean cultivars for glycinin and β-conglycinin using 2-DE.…”

Analysis of Peptides and Proteins by Electrophoretic Techniques

“…Turcz.) was approximately twice as high as that of the Indica rice cultivar [200]. Zarkadas et al [195] also reported great variability among soybean cultivars for glycinin and β-conglycinin using 2-DE.…”