Overexpression of Tomato SIZ2 in Arabidopsis Improves Plant Salinity Tolerance

Small ubiquitin-like modifier (SUMO) conjugation to target proteins is an important post-translational modification, which regulates plant tolerance to biotic and abiotic stresses. SIZ1, a well-characterized SUMO E3 ligase, facilitates the conjugation of SUMO to target proteins. Here, a SIZ/PAIS-type protein SlSIZ2 was identified in tomato (Solanum lycopersicum) that is a homolog of AtSIZ1 and SlSIZ1. SlSIZ2 was expressed in tomato vegetative and reproductive tissues, and induced by ABA and NaCl. Nucleus-localized SlSIZ2 partially rescued atsiz1-2 dwarfism and also alleviated the sensitivity of atsiz1-2 to ABA and NaCl, suggesting the functional replacement of SlSIZ2 to AtSIZ1. Moreover, SlSIZ2-overexpressing Arabidopsis has higher cotyledon expansion rate, lateral root density and survival rate under salinity stress. These results suggested the contribution of SlSIZ2 to the tolerance of salinity stress.

Automated summary

The SlSIZ2 protein in tomato plays an important role in plant tolerance to biotic and abiotic stress, regulating the tolerance to salinity stress by modifying target proteins.