TY  - JOUR
AU  - Nadirova, Leila Timurovna
AU  - Stanbekova, Gulshan Esenbekovna
AU  - Zhigailov, Andrey Viktorovich
AU  - Kryldakov, Ruslan Vladimirovich
AU  - Iskakov, Bulat Kudaibergenovich
T1  - Role of Ribosomal Protein S6 in Maintaining Translational Integrity in Plants under Osmotic Stress
JO  - Journal of Stress Physiology & Biochemistry
Y1  - 2026/august
VL  - 22
IS  - 3
SP  - 60
EP  - 68
UR  - http://www.jspb.ru/issues/2026/N3/JSPB_2026_3_60-68.pdf
KW  - 18S rRNA
KW  - Arabidopsis thaliana
KW  - osmotic stress
KW  - protoplasts
KW  - RPS6
KW  - translation
U1  - 1997-0838
N2  - Regulation of protein synthesis is essential for cellular adaptation to environmental stress. In contrast to animals and yeast, plants lack several canonical mechanisms of rapid translational repression, suggesting the existence of alternative strategies for controlling ribosome activity. Increasing evidence indicates that discrete fragmentation of ribosomal RNA may represent one such mechanism in plant cells.
In this study, we examined the role of ribosomal protein S6 (RPS6) in stress-associated 18S rRNA fragmentation in Arabidopsis thaliana. Wild-type (Col-0) and rps6a knockout protoplasts were subjected to osmotic stress (250 mM NaCl). Ribosomal RNA integrity was assessed by denaturing polyacrylamide gel electrophoresis followed by Northern blot hybridization using probes specific to the 5′ and 3′ termini of 18S rRNA.
Osmotic stress induced significant accumulation of a 75-nt 5′-terminal fragment in wild-type cells. In the RPS6A knockout line, elevated basal levels of this fragment were observed even in the absence of stress. In contrast, the  100-nt 3′-terminal fragment exhibited reduced abundance in the mutant background and showed distinct stress-dependent dynamics.
These findings demonstrate that RPS6 contributes to maintaining 18S rRNA structural integrity and differentially modulates region-specific fragmentation under osmotic stress. The results support a model in which discrete 18S rRNA fragmentation represents a ribosome-centered layer of translational regulation integrated with stress-responsive signaling pathways in plants.
ER  -