Cytoprotective ribonuclease (RNase) required for resistance to abiotic stresses, acting as a positive regulator of mRNA decapping during stress (PubMed:25736060). Essential for the integrity and function of cytoplasmic messenger ribonucleoprotein (mRNP) complexes called stress granules (SGs) and processing bodies (PBs), sites of post-transcriptional gene regulation during stress (e.g. salt and heat) (PubMed:25736060). Involved in gibberellic acid (GA) biosynthesis (PubMed:25205572). Essential for stress tolerance, probably by regulating mRNAs entering the secretory pathway (PubMed:20484005). Component of stress granules (SGs) that regulates growth under salt stress by modulating levels of GA20OX3 mRNA. Binds GA20OX3 mRNA (PubMed:25205572). May inhibit the degradation of mRNAs involved in stress adaptation (PubMed:26237081). Repressed by the specific inhibitor 3',5'-deoxythymidine bisphosphate (pdTp); this RNase activity inhibition impairs subcellular relocation upon abiotic stress and leads to reduced stress resistance. Accumulates heterogeneously in the cytosol, in patches around the nucleus and in the cell periphery, and relocates transiently to a diffuse pattern in response to salt stress (PubMed:20484005). Accumulates in cytoplasmic stress granules (SGs) and processing bodies (PBs) in response to abiotic stresses (e.g. salt and heat) (PubMed:25205572, PubMed:25736060). Expressed in seeds, leaves, flowers, roots and siliques (at protein level) (PubMed:20396901, PubMed:20484005). Accumulates in the cap and elongation zone of the root apices (at protein level) (PubMed:20484005). Accumulates after salt treatment. TNase-like domains are required for relocation to cytoplasmic foci upon abiotic stresses. Normal vegetative growth, flowering time and flower morphology (PubMed:20396901). Reduced expression of enzyme involved in GA biosynthesis leading to reduced levels of GA-4 (e.g. GA20OX3). Slower growth in salt conditions (PubMed:25205572). The double mutant tsn1 tsn2 exhibits severe alteration in germination, growth, and survival under high salinity stress. Reduced levels of stress-regulated mRNAs encoding secreted proteins (PubMed:20484005). Abnormal stress granules (SGs) and processing bodies (PBs) assembly accompanied by reduced uncapped RNAs levels in heat-stressed double mutant tsn1 tsn2 (PubMed:25736060). The double mutant tsn1 tsn2 is also showing enriched uncapping and subsequent degradation of mRNAs involved in stress adaptation (PubMed:26237081).