Elevated tropospheric ozone increased grain protein and amino acid content of a hybrid rice without manipulation by planting density.
BACKGROUND
Rising tropospheric ozone affects crop yield and quality. Rice protein concentration, which is closely associated with eating/cooking quality, is of critical importance to nutritional quality. The ozone effect on amino acids of rice grains was little known, especially grown under different cultivation conditions. A hybrid rice cultivar Shanyou 63 was grown in 2010 and 2011 to investigate the interactive effect of ozone exposure and planting density on rice protein quality in a free-air ozone enrichment system.


RESULTS
The content of protein, total amino acids (TAA), total essential (TEAA) and non-essential amino acids (TNEAA) in rice grain was increased by 12-14% with elevated ozone. A similar significant response to ozone was observed for concentrations of the seven essential and eight non-essential amino acids. In contrast, elevated ozone caused a small but significant decrease in percentage of TEAA to TAA. The year effect was significant for all measured traits; however, interactions of ozone with year or planting density were not detected.


CONCLUSIONS
The study suggested that season-long elevation of ozone concentration to projected 2050 levels will increase protein and amino acids of Shanyou 63, and crop management such as changing planting density might not alter the impact.
Key Laboratory of Agricultural Meteorology, Jiangsu Province, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China.
Xiaodong
X
Zhou
Juan
J
Zhou
Yunxia
Y
Wang
Bin
B
Peng
Jianguo
J
Zhu
Lianxin
L
Yang
Yulong
Y
Wang
D000383:Agriculture / Q000379:methods; D000596:Amino Acids / Q000032:analysis*; D006824:Hybridization, Genetic; D009753:Nutritive Value; D012275:Oryza / Q000737:chemistry* / Q000187:drug effects / Q000254:growth & development*; D010126:Ozone / Q000494:pharmacology*; D010940:Plant Proteins / Q000032:analysis*; D012639:Seeds / Q000737:chemistry
D000596:Amino Acids; D010940:Plant Proteins; D010126:Ozone
amino acids; planting density; protein; rice grains; tropospheric ozone