Effect of Halloysite Nanotubes on Growth of Wheat under Copper Stress
Three copper(Cu)treatments[20 mg/L Cu2+(20Cu),50 mg/L Cu2+(50Cu)and 100 mg/L Cu2+(100Cu)]were set up under hydroponics to study the effect of exogenous addition of 50 mg/L halloysite nanotubes(HNTs)on wheat seedling growth,stomata size,chloroplast pigment content,oxidative damage of roots and Cu2+content in plants under Cu stress,so as to provide theoretical basis for HNTs to alleviate the effects of heavy metal pollution on crop growth.The results showed that exogenous addition of HNTs significantly increased the plant height and root length of wheat seedlings under Cu stress,the plant height of 20Cu+HNTs,50Cu+HNTs and 100Cu+HNTs treatments increased by 13.10%,26.45%and 28.30%,and the root length increased by 62.87%,56.68%and 92.34%,respectively.Exogenous addition of HNTs significantly increased the dry and fresh weight of wheat seedlings,chlorophyll and carotenoid contents of wheat seedlings under Cu stress,as well as root activity,and reduced the oxidative damage degree of roots,among which chlorophyll a content increased by 34.34%,18.09%and 54.76%,chlorophyll b content increased by 44.83%,25.93%and 43.75%,and root activity increased by 38.16%,339.48%and 453.56%,respectively.Compared with 100Cu treatment,the Cu2+content in roots and leaves of wheat seedlings of 100Cu+HNTs treatment decreased by 19.18%and 37.02%,respectively.In conclusion,exogenous addition of HNTs can reduce Cu2+content in wheat seedlings,alleviate the toxicity of heavy metal Cu to wheat seedlings,and promote their growth.
WheatHalloysite nanotubesCopper stressGrowth and developmentMitigation