title: Chalky part differs in chemical composition from translucent part of japonica rice grains as revealed by a notched-belly mutant with white-belly.
abstract: BACKGROUND
  Chalkiness has a deleterious influence on rice appearance and milling quality. We identified a notched-belly mutant with a high percentage of white-belly, and thereby developed a novel comparison system that can minimize the influence of genetic background and growing conditions. Using this mutant, we examined the differences in chemical composition between chalky and translucent endosperm, with the aim of exploring relations between occurrence of chalkiness and accumulation of starch, protein and minerals.
  
  
  RESULTS
  Comparisons showed a significant effect of chalkiness on chemical components in the endosperm. In general, occurrence of chalkiness resulted in higher total starch concentration and lower concentrations of the majority of the amino acids measured. Chalkiness also had a positive effect on the concentrations of As, Ba, Cd, Cr, Mn, Na, Sr and V, but was negatively correlated with those of B, Ca, Cu, Fe and Ni. By contrast, no significant chalkiness effect on P, phytic acid-P, K, Mg or Zn was observed. In addition, substantial influence of the embryo on endosperm composition was detected, with the embryo showing a negative effect on total protein, amino acids such as Arg, His, Leu, Lys, Phe and Tyr, and all the 17 minerals measured, excluding Ca, Cu, P and Sr.
  
  
  CONCLUSIONS
  An inverse relation between starch and protein as well as amino acids was found with respect to chalkiness occurrence. Phytic acid and its colocalized elements K and Mg were not affected by chalkiness. The embryo exerted a marked influence on chemical components of the endosperm, in particular minerals, suggesting the necessity of examining the role of the embryo in chalkiness formation. © 2016 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Zhaomiao
authors.initials: Z
authors.lastname: Lin
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Deyi
authors.initials: D
authors.lastname: Zheng
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Xincheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Zunxin
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Jinchao
authors.initials: J
authors.lastname: Lei
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.|Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing 210095, People's Republic of China.
authors.forename: Zhenghui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Ganghua
authors.initials: G
authors.lastname: Li
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.|Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing 210095, People's Republic of China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Ding
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000378:metabolism; D002681:China; D004040:Dietary Carbohydrates / Q000032:analysis* / Q000378:metabolism; D056625:Endosperm / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D008274:Magnesium / Q000032:analysis / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D009753:Nutritive Value; D012275:Oryza / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010833:Phytic Acid / Q000032:analysis / Q000096:biosynthesis; D014674:Plant Proteins, Dietary / Q000032:analysis* / Q000096:biosynthesis; D011188:Potassium / Q000032:analysis / Q000378:metabolism; D012639:Seeds / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013213:Starch / Q000032:analysis / Q000096:biosynthesis; D014131:Trace Elements / Q000032:analysis* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D004040:Dietary Carbohydrates; D014674:Plant Proteins, Dietary; D014131:Trace Elements; D010833:Phytic Acid; D013213:Starch; D008274:Magnesium; D011188:Potassium
keywords: chalkiness; chemical composition; minerals; phytic acid; rice