Abstract:

Pinus massonianaseedling was used to investigate effects of Dendrolimus punctatuschewing, MeJA and terpenes treatments on the contents of γaminobutyric acid and 17 free amino acids with the technology of Ophthaldialdehyde 9 fluorenylmethyl chloroformate（OPAFMOC) precolumn derivation, along with high performance liquid chromatography gradient elution method. The damaged shoots, the sister shoots (the opposite), the systematic upper shoots (above the damaged shoots) and the systematic lower shoots (under the damaged shoots) were sampled after being injured by the insects, being treated by the MeJA and the terpenes for 4 hours. Results showed that different modes of damage considerably and systematically caused the changes of GABA and 17 free amino acids in P. massionianaseedlings. Contents of GABA increased distinctly in the shoots damaged by the insect, treated with MeJA (10 μmol\5L^-1) and terpenes (10 μmol\5L^-1), and in their sister shoots and the systematic shoots. The total contents of amino acids decreased in the leaves of the shoots chewed by the insect and treated with MeJA (10　μmol·L^－1), and of the sister shoots and the systematic shoots. The total contents of amino acids decreased in the shoots treated with terpenes (10　μmol·L^－1) and the systematic lower shoots, however, increased in the sister shoots and the systematic upper shoots. It was concluded that MeJA and terpenes induced the similar defensive systems as the insect did, and could replace the insect to signal and initial the defensive system to defend against the outer attack.

Key words: Pinus massoniana, Dendrolimus punctatus, methyl jasmonate, terpenes, γ aminobutyric acid, free amino acid