2.6 Verification with significant difference of exogenous.
Based on the above results (plant hormone, flavonoids and phenolic acids), JA, SA, MT and API were selected to test their effect on wheat seedlings growth. Different concentration (0, 1, 5, 10 and 50 mg/L) of each compound was sprayed on the wheat seedlings. Among the 17 treatments, wheat plant height, root length, fresh weight, dry weight, along with phytohormone and antioxidant capacity, were measured and showed Figure S1-S4. MT at the applied rate of 10 mg/L demonstrated showed the highest impacts on the wheat seedling growth based on the observed results (Figure S1-S4). Next, nano-Se (5mg/L) and MT (10mg/L) were tested for their effects on S. avenae. Aphids numbers and changes of wheat compounds were measured. Each treatment was set up with five replicates. Wheat growth conditions and aphid infestation were same as the before.
2.7 RNA Extraction and Real-Time Quantification .
Four groups of wheat plants were prepared for RNA-seq. The total RNA was extracted using RNA pure Plant Kit (Tiangen Biotech, Beijing, China). Then, total RNA was reverse transcribed to cDNA according to instructions of the manufacturer (TURE script 1st Stand cDNA SYNTHESIS Kit). The RT-qPCR was performed using a CFX 96 PCR system (Bio-Rad) with Super Real PreMix Plus Kit (SYBR Green). Table S6 provides the primers of RT-qPCR for genes involved in DIMBOA and MT synthesis.