Proteomic analysis of reserve proteins in commercial rice cultivars

Salting-out effect-mediated size-control of protein nanoparticles towards controllable microstructures for sustained release of eugenol

Size and monodispersity of solid particles are essential to their structuring behaviors at biphasic interfaces. However, delicate control over biomolecular nanoparticle sizes is challenging. In this study, we prepared monodisperse rice protein (RP) nanoparticles by neutralizing RP solutions (pH 12.0) using combined treatments of cationic exchange resins (CERs) and HCl. CERs absorbed Na+ by releasing H+ without producing salt during neutralization. By compromising the usages of CERs and HCl when preparing RPs, the generation of NaCl can be delicately tailored, leading to controllable nanoparticle sizes from 20 nm to 30 nm. By mixing these nanoparticles with eugenol in an aqueous solution, the nanoparticles accommodated eugenol in their cores due to inward diffusion. Furthermore, such eugenol-contained nanoparticles with different sizes demonstrated tunable releases of eugenol due to size-dependent capillary forces, which can be harnessed for suppression of microbial growth on fruit with prolonged effective eugenol concentration.

[Simultaneous determination of three allergic proteins in rice and products by high performance liquid chromatography-tandem mass spectrometry combined with stable isotope-labeled peptides]

基于稳定同位素标记特征肽段和液相色谱-质谱联用仪建立稻米及制品中3种过敏蛋白质的同时定量方法。稻米及制品样品经盐溶液提取,赖氨酰基内切酶(Lys-C)和胰蛋白酶依次水解,C18-SD柱净化后,采用纳升高效液相色谱-线性离子阱-静电场轨道阱(NanoLC-LTQ-Orbitrap)采集和Protein Discovery软件鉴定,NCBI和Uniprot数据库的基本局部搜索比对工具(BLAST)筛选验证,最终获得表征稻米及制品中α-淀粉酶/胰蛋白酶抑制剂类蛋白质(seed allergenic protein RAG2, RAG2)、乙二醛酶Ⅰ活性蛋白(glyoxalase Ⅰ)和α-球蛋白(19 kDa globulin)3种过敏蛋白质的特异性肽段。3个特异性肽段经液相色谱梯度洗脱,在Poroshell色谱柱上实现完全分离,由三重四极杆质谱仪分析。实验通过优化多反应监测(MRM)质谱参数,比较不同溶剂体系、水解酶种类和酶量等酶解条件,结合内标法定量,实现对稻米及制品中3种蛋白质的绝对定量。实验结果表明,当酶解溶剂中含1 g/L十二烷基硫酸钠,采用Lys-C和胰蛋白酶组合消化策略,可有效提高3种蛋白质的酶切效率至65.7%~97.3%。该方法在1~200 nmol/L范围内线性关系良好,相关系数均大于0.9972, 3种蛋白质的检出限和定量限分别为3 mg/kg和10 mg/kg。3种蛋白质在空白稻米制品基质中3个水平下的加标回收率为80.6%~103.7%,日间和日内精密度均小于11.5%。该方法稳定性好,检测灵敏度高,操作简便,在分析各类稻米及制品中3种过敏蛋白质含量具有广泛的应用前景。

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

Rice (Oryza sativa) is an imperative staple crop for nearly half of the world's population. Challenging environmental conditions encompassing abiotic and biotic stresses negatively impact the quality and yield of rice. To assure food supply for the unprecedented ever-growing world population, the improvement of rice as a crop is of utmost importance. In this era, "omics" techniques have been comprehensively utilized to decipher the regulatory mechanisms and cellular intricacies in rice. Advancements in omics technologies have provided a strong platform for the reliable exploration of genetic resources involved in rice trait development. Omics disciplines like genomics, transcriptomics, proteomics, and metabolomics have significantly contributed toward the achievement of desired improvements in rice under optimal and stressful environments. The present review recapitulates the basic and applied multi-omics technologies in providing new orchestration toward the improvement of rice desirable traits. The article also provides a catalog of current scenario of omics applications in comprehending this imperative crop in relation to yield enhancement and various environmental stresses. Further, the appropriate databases in the field of data science to analyze big data, and retrieve relevant information vis-à-vis rice trait improvement and stress management are described.

Exergy flow of rice production system in Italy: Comparison among nine different varieties

Exergy analysis is receiving considerable attention as an approach to be applied for making decisions toward moving to a sustainable and energy-efficient food supply chain. This study focuses on how the selection of variety affects the exergy flow of a paddy rice production system. In this regard, nine varieties of rice in Italy, the largest rice producer in Europe, were evaluated using the cumulative exergy analysis approach. Sensitivity analysis of inputs consumption and the exergy management scenarios of the most sensitive inputs are also provided in this study. The results indicated that the cumulative exergy consumption value of the investigated rice varieties ranges from 16.09 GJha^-1 to 25.80 GJ ha^-1. Fossil fuels and chemical fertilizer consumption were the most significant contributors to the total energy consumption in all investigated varieties. Luna variety, with the cumulative degree of perfection value of 7.96 and renewability indicator of 0.88, was identified as the most exergy-efficient variety of rice in Italy.

iTRAQ-based quantitative glutelin proteomic analysis reveals differentially expressed proteins in the physiological metabolism process during endosperm development and their impacts on yield and quality in autotetraploid rice

Autotetraploid rice, which is developed through chromosome set doubling using diploid rice, produces high-quality kernels that are rich in storage proteins. However, little information is available about the content of different proteins in autotetraploid rice and their proteomic analysis. The dynamic changes in four storage proteins, namely, albumin, globulin, prolamin, and glutelin, were analyzed in the endosperm of autotetraploid rice (AJNT-4x) and in that of its diploid counterpart (AJNT-2x) for comparison. The contents of the four proteins were all higher during endosperm development in AJNT-4x than in AJNT-2x, but their change and composition were almost the same in the two materials. Then, iTRAQ was employed to analyze the glutelin profiles of AJNT-4x and AJNT-2x at 10 DAF, 15 DAF, and 20 DAF. A total of 1326 proteins were identified in AJNT-4x and AJNT-2x using high-throughput LC-MS/MS. Among the 1326 identified proteins, there were 362 DEPs in AJNT-4x compared with AJNT-2x and 372 DEPs between different developmental stages in AJNT-4x. Eight important upregulated proteins were identified by qRT-PCR, including B8AM24, B8ARJ0, B8AQM6, A2ZCE6, and P37833. Among them, B8AM24 and B8ARJ0 were related to the lysine biosynthesis process. GO enrichment analysis revealed that the critical functions of DEPs exhibited little overlap between the 10, 15, and 20 DAF groups. Endosperm glutelin accumulation was regulated mainly by different DEPs during the early stage, and 15 DAF was a critical regulating point for glutelin accumulation. KEGG pathway analysis showed that ribosomal proteins were significantly higher in AJNT-4x than in AJNT-2x at 10 DAF, and protein processing, biosynthesis, and metabolism of amino acids were higher and more active in AJNT-4x at 15 DAF, while the peroxisome was richer in AJNT-4x at 20 DAF. The PPI network showed that ribosomal proteins gradually decreased with increasing endosperm development. These results provide new insights into dynamic glutelin expression differences during endosperm development in autotetraploid rice, which will aid in the development of rice cultivars with increased yield and improved grain nutritional quality.