Binucleate induced tomato resistance against via affecting antioxidants and cell wall reinforcement.

Isolates of (AG-3 PT, AG-4 HG-I, AG-4 HG-II) and one binucleate sp. (BNR) belonging to AG-Bb were investigated for pathogenicity on tomato cultivar Mobil. The BNR isolate revealed the lowest virulence and it was used as biocontrol agent against AG-4 HG-II, which showed the highest virulence on tomato. Inoculation of tomato plants with the hypovirulent BNR isolate reduced the disease symptoms of and induced resistance. Resistance induction was observed not only on the plants simultaneously inoculated with BNR and , but also when the plants were inoculated by the BNR and with time intervals. The peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT) activities and expression levels of the corresponding genes in tomato plants increased after or BNR inoculation. The highest level of antioxidant activities and expression of their genes, lignin and callose formation were observed in the plants inoculated with the BNR and , simultaneously. The BNR inoculation reduced HO accumulation. The highest level of priming was observed for the POX among other antioxidants tested via application of the BNR. Treatment with potassium cyanide (as a POX inhibitor) reduced basal resistance and BNR-induced resistance (BNR-IR) via reduction of lignification and callose deposition in tomato plants. These findings demonstrated the role of antioxidant enzymes, mainly the POX, in both basal resistance and BNR-IR. Therefore, redox state and antioxidants are involved in cell wall strengthening via lignin and callose formation, as important defense components which decrease the pathogen progress in plant tissues.