Overexpression of SIZ1 enhances tolerance to cold and salt stresses and attenuates response to abscisic acid in Arabidopsis thaliana

Abstract

Sumoylation is a post-translational modification to control several cellular functions, including responses to environmental stresses and hormones in plants, and SIZ1 is a SUMO (small ubiquitin-related modifier) E3 ligase that plays an important role in sumoylation. In this study, we produced transgenic Arabidopsis thaliana plants with a moderately higher expression of SIZ1. Compared to wild type, the transgenic plants, with or without cold acclimation, were tolerant to freezing stress when subjected to freezing temperatures. The transgenic plants exhibited enhanced performance associated with robust shoot and root growth under salinity stress, whereas the wild type exhibited necrosis in the leaves with salt treatment. Furthermore, SIZ1 overexpression attenuated the root growth inhibition caused by abscisic acid. These results suggest that SIZ1 has the potential to genetically improve plant responses to abiotic stresses.

The PHD finger of Arabidopsis SIZ1 recognizes trimethylated histone H3K4 mediating SIZ1 function and abiotic stress response

“…PIAL1 and PIAL2 function as E4-type SUMO ligases to promote SUMO chain formation and are involved in salt and osmotic stress responses 23 . Among these four SUMO E3 ligases, SIZ1 has high similarity to yeast Siz and animal PIAS orthologs 24 , which contain SAP and SP-RING domains and PINIT (for Pro-Ile-Asn-Ile-Thr) and SXS (Ser-any amino acid-Ser) motifs 15,25 . However, only plant SIZ proteins contain a PHD (plant homeodomain) finger, which is a C 4 HC 3 (four cysteines, one histidine, and three cysteines) zinc-finger-like motif.…”

Post‐translational modifications of Arabidopsis E3 SUMO ligase AtSIZ1 are controlled by environmental conditions

“…Arabidopsis E3 SUMO ligase is involved in several developmental processes including germination, nutrient assimilation, hormone signaling, and flowering . In addition, plant E3 SUMO ligases have important roles in the responses to abiotic stresses such as low temperature, drought, heat, and high salt .…”

Accumulation of endogenous salicylic acid confers drought tolerance toArabidopsis

“…[3][4][5] Reactive oxygen species (ROS) levels in siz1 guard cells are higher than those in the wild-type guard cells and light-induced stomatal opening was inhibited by the siz1 mutation, reducing water loss and enhancing drought tolerance. 6 These phenotypes are suppressed by introduction of nahG gene, which encodes a salicylate hydroxylase that catalyzes the conversion of SA to catechol, into the siz1 mutant.…”