Brassinosteroids act as a positive regulator for resistance against root-knot nematode involving RESPIRATORY BURST OXIDASE HOMOLOG-dependent activation of MAPKs in tomato.

Interplay of hormones with reactive oxygen species (ROS) fine-tunes the response of plants to stress; however, the crosstalk between brassinosteroids (BRs) and ROS in nematode resistance is unclear. In this study, we found that low BR biosynthesis or lack of BR receptor increased, whilst exogenous BR decreased the susceptibility of tomato plants to Meloidogyne incognita. Hormone quantification coupled with hormone mutant complementation experiments revealed that BR did not induce the defence response by triggering salicylic acid (SA), jasmonic acid/ethylene (JA/ET) or abscisic acid (ABA) signalling pathway.