Seed Coating with Triflumezopyrim Induces the Rice Plant’s Defense and Inhibits the Brown Planthopper’s Feeding Behavior

Abstract

Triflumezopyrim (TFM), a novel mesoionic insecticide, has been effective in controlling sucking insect pests such as the brown planthopper (BPH). However, the mechanism of TFM as a seed coating agent in paddy fields remains unclear. Here, we investigate the seed germination rates (>80%) and seedling emergence rates (>85%) of rice treated with TFM at 0, 22.5, 45.0, 67.5, and 90.0 g a.i. ha−1 with no significant effect on germination rates. In addition, the low TFM residue concentration (0.04 mg. kg−1) is maintained in the rice stem. Meanwhile, the TFM seeds’ treatments lead to increased oxalic acid, flavonoids, total phenol, callose contents, and elevated C/N ratio in rice plants at 60 and 90 days after sowing (DAS). The electrical penetration graph (EPG) results indicate that TFM as a seed coating treatment prolongs the non-probing period and inhibits phloem sap ingestion at 90 DAS. Furthermore, the mechanically transplanted rice treated with TFM provides long-term prevention against the BPH infestation. This study demonstrates that seeds treated with TFM play a vital role in controlling the BPH population up to >90%. These results provide a novel valuable control strategy for BPH in the rice fields.

Seed Priming of Rice Varieties with Decoyinine Improve Their Resistance against the Brown Planthopper Nilaparvata lugens

“…In addition, the weights of female BPHs fed on DCY100-pretreated plants of two rice varieties were decreased significantly (Figure 8), and these results were consistent with those of a previous study [27]. Recent studies have indicated that treating seeds with triflumezopyrim enhanced rice resistance against BPH by inhibiting phloem ingestion, which resulted in the reduced fecundity of females and lowered the population in the field [42,43]. A two-way ANOVA suggested that the effect of DCY treatment on the honeydew excretions and weights of BPHs was greater than rice variety and the interactions between DCY treatment and rice variety (Table 6).…”