Gall wasps change the biochemical composition of Eucalyptus leaves

Abstract Gall wasps Leptocybe invasa and Ophelimus maskelli can cause loss of productivity by causing damage to Eucalyptus camaldulensis leaf tissues. Comparison of the biochemical compositions of noninfested and infested leaves may be useful to elucidate the roles of antioxidant defense compounds and antioxidant enzyme activities in protecting eucalyptus leaves against attack by insect pests. While glucose and fructose content increased in leaves infested by both gall wasps, proline content increased only in leaves infested by L. invasa. In flavonoid content, the reduction rate of 16.5% in leaves infested with L. invasa was 33.7% with O. maskelli. Total antioxidant capacity decreased with O. maskelli infestation but did not change with L. invasa infestation. Copper ion reduction capacity increased significantly with both pest infestations. Ascorbic acid increased by 87% in L. invasa infestation and 120% in O. maskelli infestation compared to control. The increase observed of superoxide dismutase activity in infested leaves was calculated as 29% for L. invasa and 20% for O. maskelli. O. maskelli infestation caused an increase in carotenoid content in non-infested leaves (total 7.29, Xan/Cds 5.0) but significantly decreased it in infested leaves (toplam 2.98, Xan/Cds 3.2). Superoxide generation rates of noninfested and infested leaves from the infested trees were found to be higher than those of the control samples. The biochemical composition of the infested and noninfested leaves of the infested plants also differs. The invasion of gall wasps triggers oxidative stress by increasing the rate of superoxide production in eucalyptus leaves.