Dimethyl tyrosine conjugated peptide prevents oxidative damage and death of triticale and wheat microspores

Functional damage of mitochondria and chloroplasts under stress contributes to reactive oxygen species (ROS) induced cell death. A high percentage of cell mortality during microspore culture is a limiting factor in haploid and doubled haploid plant production. In the present study, we studied the contribution of dimethyl tyrosine (DMT) conjugated short peptides to microspore embryogenesis. These DMT-peptides, which are known to translocate to subcellular targets and scavenge ROS, mitigate the effect oxidative stress plays on microspore viability and embryogenesis. The number of viable microspores was significantly higher in the presence of SS-31 and caspase-3-inhibitor (Ac-DEVD-CHO). In particular, the total number of green plant regeneration was increased by 42 % in the presence of SS-02, and by 55 % in the presence of SS-31, in triticale. Conversely, lower caspase-3-like activities were observed in the presence of SS-31 and Ac-DEVD-CHO, and intracellular ROS was reduced in the presence of SS-31, supporting the involvement of SS-31 in reducing microspore cell death by mitigating ROS and caspase-3-like activity. This study further supports the concept that antioxidant conjugated peptides offer a useful strategy for reducing ROS in plant cells.