iProXProteomicsXiaorong ChenOryza Sativahttp://www.iprox.org/page/project.html?id=IPX0001551000ccxxrr80@163.comCollege of Agronomy, Jiangxi Agricultural UniversityiProX<h4>Background</h4>The crop growth compensation effect is a naturally biological phenomenon, and nitrogen (N) is essential for crop growth and development, especially for yield formation. Little is known about the molecular mechanism of N deficiency and N compensation in rice. Thus, the N-sensitive stage of rice was selected to study N deficiency at the tillering stage and N compensation at the young panicle differentiation stage. In this study, a proteome analysis was performed to analyze leaf differentially expressed proteins (DEPs), and to investigate the leaf physiological characteristics and yield under N deficiency and after N compensation.<h4>Results</h4>The yield per plant presented an equivalent compensatory effect. The net photosynthetic rate, optimal/maximal quantum yield of photosystem II (Fv/Fm), soil and plant analyzer development (SPAD) value, and glutamic pyruvic transaminase (GPT) activity of T1 (N deficiency at the tillering stage, and N compensation at the young panicle differentiation stage) were lower than those of CK (N at different stages of growth by constant distribution) under N deficiency. However, after N compensation, the net photosynthetic rate, Fv/Fm, SPAD value and GPT activity were increased. Using an iTRAQ-based quantitative approach, a total of 1665 credible proteins were identified in the three 4-plex iTRAQ experiments. Bioinformatics analysis indicated that DEPs were enriched in photosynthesis, photosynthesis-antenna proteins, carbon metabolism and carbon fixation in the photosynthetic organism pathways. Moreover, the photosynthesis-responsive proteins of chlorophyll a-b binding protein, ribulose bisphosphate carboxylase small chain and phosphoglycerate kinase were significantly downregulated under N deficiency. After N compensation, chlorophyll a-b binding protein, NADH dehydrogenase subunit 5, NADH dehydrogenase subunit 7, and peroxidase proteins were significantly upregulated in rice leaves.<h4>Conclusion</h4>Through physiological and quantitative proteomic analysis, we concluded that a variety of metabolic pathway changes was induced by N deficiency and N compensation. GO and KEGG enrichment analysis revealed that DEPs were significantly associated with photosynthesis pathway-, energy metabolism pathway- and stress resistance-related proteins. The DEPs play an important role in the regulation of N deficiency and the compensation effect in rice.iTRAQ-based quantitative proteomic and physiological analysis of the response to N deficiency and the compensation effect in rice.Xiong Qiangqiang Q, Zhong Lei L, Shen Tianhua T, Cao Chaohao C, He Haohua H, Chen Xiaorong XfalseRice Leaf Proteome with Three 4-plex iTRAQ Experiments by Liquid Chromatograph Mass SpectrometryBased on ecological crop nutrient deficiency and compensation effect theory, the nitrogen (N)-sensitive stage of rice was selected to study N deficiency at the tillering stage and N compensation at the young panicle differentiation stage. Quantitative proteomics was used to analyze leaf differentially expressed proteins (DEPs), and to investigate the leaf photosynthetic characteristics and yield under N deficiency and N compensation. The results showed that the yield per plant presented an equivalent compensatory effect (CI=1.07). The net photosynthetic rate (Pn), optimal/maximal quantum yield of PSII (Fv/Fm), soil and plant analyzer development (SPAD) value, and glutamic pyruvic transaminase (GPT) activity of T1 (N deficiency at the tillering stage, and N compensation at the young panicle differentiation stage) were lower than those of CK (N at different stages of growth by constant distribution) under N deficiency. However, after N compensation, the Pn, Fv/Fm, SPAD value, and GPT activity increased somewhat. Bioinformatics analysis indicated that DEPs that were enriched in photosynthesis, photosynthesis-antenna proteins, carbon metabolism, and carbon fixation in the photosynthetic organisms pathways were important for the maintenance of cellular homeostasis and metabolic balance in rice when subjected to N deficiency and N compensation. Moreover, the photosynthesis-responsive protein chlorophyll a-b binding protein, ribulose bisphosphate carboxylase small chain, and phosphoglycerate kinase were significantly downregulated under N deficiency. After N compensation, chlorophyll a-b binding protein, NADH dehydrogenase subunit 5, NADH dehydrogenase subunit 7, and peroxidase proteins were significantly upregulated in rice leaves. This study provides a new ecological perspective for N utilization in rice.Sun Mar 24 00:00:00 GMT 2019PXD013206453031462233