## 2 Materials and Methods
### Processing and Sampling of _A. sinensis_  
The experiment employed a randomized complete block design with six treatments and three temporal replicates. Thirty-six healthy 8-year-old _A. sinensis_ trees with comparable growth status (DBH 15 \(\pm\) 2 cm, height 4 \(\pm\) 0.5 m) were randomly assigned to six treatment groups (n = 6 trees per group): cold drilling treatment, fungal induction treatment, PDA treatment, insect boring treatment, insects combined with fungi treatment, and untreated control. All mechanical interventions were performed by trained technicians using sterilized tools. Between-tree contamination was prevented using disposable gloves and surface-disinfected equipment (75% ethanol). Treatments were applied during morning hours (08:00-10:00) to minimize circadian rhythm effects. The cold drilling treatment used a puncher positioned 50 cm from the ground at an inclination angle of 45\({}^{\circ}\). From the base to the apex of the trees, each trunk was drilled in four directions--east, south, west, and north--with an average of 4 holes, a pore size of 1 cm, hole spacing of 7 cm, a depth of 3-4 cm, and row spacing of 15 cm, with a total of 9 rows. The fungal induction treatment was based on the cold drilling treatment. A 5 mm sterilized puncher was used to punch holes in the activated fungal PDA plate; a fungal block was placed in the pre-made hole using a sterile bamboo stick, and then the holes were sealed from first to last using parafilm. The PDA treatment involved inserting sterile PDA blocks into the hole using the same process as in the fungal induction method, which was based on the cold drilling treatment. For the insect boring treatment, based on the cold drilling treatment, sterile tweezers were used to insert the insect into the hole, and then the hole was covered with parafilm from the base to the apex of the trees and pricked with a needle to allow for gas flow. For the treatment involving insects combined with fungi, based on the cold drilling treatment, insects were held with tweezers, dipped into a beaker containing fungal suspension for 5-10 s, and quickly placed in the hole, which was then sealed. For the blank treatment, the above induction techniques were not required, and the trees were left to grow naturally. Systematic destructive sampling was conducted at 2, 4, and 6 months post-induction, with 2 trees per treatment group sampled at each time point. Using an autoclaved coring tool (150 mm diameter, 200 mm maximum depth), three vertical sampling zones were established along the trunk: lower (0-50 cm above ground), middle (50-100 cm), and upper (100-150 cm). Within each vertical zone, three equidistant horizontal quadrants (120\({}^{\circ}\) apart, aligned with the original treatment orientations of east, south, west, and north) were sampled, maintaining a 2 cm buffer from treatment hole edges to avoid boundary effects. Each tree yielded 9 standardized core samples (3 vertical zones \(\times\) 3 horizontal quadrants) with \(\geq\)15 cm spacing between adjacent sampling points. For artificially treated groups, samples were specifically collected from the reactive interface between induced resinous tissue and healthy xylem, identified by in situ dark pigmentation. Untreated controls were equivalently sampled from healthy xylem in non-manipulated trunk regions. Samples were immediately flash-frozen in liquid nitrogen and stored at \(-80\)\({}^{\circ}\)C.