叶面喷施氨基酸对水稻Cd转运特性和稻米氨基酸含量的影响OA北大核心CSTPCD

To investigate the potential of foliar application with amino acids in inhibiting Cd transport,changes in the Ca,Fe,Mn,Zn,and amino acid content of rice were analyzed after spraying six amino acids during the flowering stage of rice plants in Hunan.Experimental results showed that spraying 10 mmol·L-1 phenylalanine(Phe),glycine(Gly),isoleucine(Ile),serine(Ser),methionine(Met),and 0.02 mmol·L-1 tryptophan(Trp)twice significantly reduced the content of Cd in rice grains,spike necks,and the uppermost nodes.The average Cd content in rice grains decreased from 0.63 mg·kg-1 to 0.27-0.48 mg·kg-1,respectively.Spraying Ser,Trp,and Met reduced rice Cd by 51.1%-57.3%;whereas Phe and Gly reduced rice Cd by 24.7%-35.1%,respectively.At the same time,the content of Ca and Fe in rice organs increased significantly,while Mn content decreased significantly and Zn content showed small fluctuations.Spraying amino acids had no significant effect on the transfer coefficient of Cd between rice organs,but significantly reduced the ratios between Cd content and the content of Ca,Fe,or Mn in rice grains,spike necks,and the uppermost nodes.Spraying Ser and Met increased the content of essential amino acids in rice by 7.5%and 10.5%,and non-essential amino acids by 13.9%and 5.5%,respectively.After application of the six amino acids,the content of glutamate,leucine,and cysteine in rice was significantly increased.Cd content in rice was positively correlated with the value of Cd∶Ca,Cd∶Fe,and Cd∶Mn,but negatively correlated with glutamate and Ca content.These results indicate that spraying Ser,Trp,and Met can efficiently reduce the Cd content in rice grains,spike necks,and the uppermost nodes by promoting the transport of Ca and Fe ions and synthesis of glutamate,as well as improving the interception ability of Ca,Fe,and Mn channels to Cd ions.