Seminar

Diversity of the SUMOylation system in Arabidopis

Maria Lois, PhD

In plants, regulation of protein activity by SUMO (Small Ubiquitin-like Modifier) attachment is a posttranslational modification that has been shown to be essential during seed development and to have a major role in abiotic and biotic stress responses. A common property between plants and animals is that SUMOylation system appears to be a target for pathogenic effectors and, SUMO conjugates accumulation in response to heat and oxidative stresses also seems to be a universal property of the system. But there are also biological processes specific to plants in which SUMO has a relevant role such as flowering, phosphate starvation, drought responses, and abscisic acid signaling pathway, hormone that mediates plant responses to environmental stresses and a key regulator of plant growth and development.

However, much less is known about the molecular mechanisms that regulate sumoylation and the complexity of the sumoylation components is apparently higher when compared to other organisms. In our group we are focused in getting a better understanding of the sumoylation machinery as a means to develop new tools for crop improvement. For this, we have analyzed the molecular properties of the Arabidopsis SUMO paralogs and the SUMO activating enzyme isoforms. Our results indicate that these components of the system are functionally divergent and support an in vivo functional specialization.