Abstract:
Objective to illustrate the nutrition relationship of free amino acids in aphid Schlechtendalia chinensis, horn gall and host plant Rhus chinensis during their cooperative growth.
Method The contents of free amino acids in aphid, horn gall, leaf with gall, leaf without gall and CK (leaf on the tree without aphid) were detected by automatic amino acid analyzer Biochrom30+, and the total amount of free amino acids (FAA), the content of essential amino acids (EAA), the ratio of EAA/TAA and several free amino acids in the early, middle and later stages of gall growth were analyzed by variance analysis.
Result All samples in different stages contained the same components, including 32 free amino acids (17 protein amino acids and 15 non-protein amino acids) and 2 other components (no ammonia). The concentration of free amino acids (FAA) from big to small was aphid (5.569) > horn gall (2.122) > leaf with gall (0.560) > leaf not gall (0.537) > CK (-0.114). The amount of EAA in aphids increased gradually with the generation increasing. The variation range of EAA/TAA from big to small was CK (1.73%)>leaf with gall (0.52%) = leaf without gall (0.52%)>horn gall (0.43%) >aphid (0.02%). And the EAA/TAA of aphids was stable at 27.91 + 0.01%. It indicated that the parasitation of aphid may decrease the variation range of EAA/TAA in the tree significantly. The contents of arginine and phenylalanine in aphids increased by 2.93 times during the growth of horn gall, and the content of proline in plant tissues also increased, and its increasing range from big to small was horn gall (0.028) > leaf with gall (0.003) > leaf without gall (-0.001) > CK (-0.018).
Conclusion The aphid parasitation cannot change the amino acid components in leaves of R. chinensis, but increase the concentrations of free amino acids. The increasing trend of total free amino acids in R. chinensis is almost consistent with the increasing trend of the aphid individual number and horn gall volume during the gall growth process and that may reflect the balance between the aphid feeding and plant defense.