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Takehiro A. Ozawa@tkozawa.bsky.social · 8mo ago

Great preprint by Liu, Blanford et al. (2025) on how trehalose 6-phosphate #T6P stimulates plant cell growth via #PlantTOR and is required for sucrose-induced TOR activation in #Arabidopsis by suppressing #SnRK1 in a dose-dependent manner, thereby mediating the antagonistic TOR–SnRK1 relationship.

Fig. 3. Trehalose 6-phosphate (T6P) is required for sucrose-mediated TOR activation. a) Exogenous T6P induces stronger TOR activation than sucrose during resupply of starved suspension cells. Starved suspension cells derived from an Arabidopsis S6K1-HA OX seedlings were resupplied with 0.5% of basal sucrose plus 100 μM sucrose or 100 μM T6P (0–2 h). Representative immunoblots show S6K1-HA, phosphorylated S6K1-HA (pS6K1-HA), phosphorylated RPS6 (pRPS6), and RPS6 at the indicated time points. Phos-tag gels separate phospho-S6K1-HA. Ponceau S serves as loading control. Band intensities were quantified using GelAnalyzer 23.1.1 and normalized to total protein. pRPS6/RPS6 ratios (n=3) were quantified for TOR activity (Šídák's Multiple Comparisons Test: *, P < 0.05; **, P < 0.01; ***, P < 0.001). b) Endogenous T6P is essential for TOR activation. In WT seedlings, sucrose resupply robustly activates TOR, whereas tps1 mutants show only weak activation. 3-d-old seedlings germinated on ½ MS (1% sucrose) (long-day conditions) were transferred to ½ MS liquid medium and starved for 4 d in dark. Seedlings were then resupplied with 1% sucrose ± 1 μM Torin2. Samples at 0.5–4 h. Representative immunoblots and quantified TOR activity (described as in a) are shown. c) Modulating T6P alters sucrose-mediated TOR activation. Arabidopsis lines overexpressing otsA (encoding E. coli T6P synthase) accelerates and otsB (encoding T6P phosphatase) delays TOR activation relative to WT. 3-d-old WT, otsA and otsB seedlings germinated on ½ MS (1% sucrose) (long-day conditions) were transferred to ½ MS liquid medium and starved for 4 d in dark. Seedlings were then resupplied with 1% sucrose . Samples at 0.5–4 h. Representative immunoblots and quantified TOR activity (described as in a) are shown. Fig. 4f. Trehalose 6-phosphate (T6P) activates Target of Rapamycin (TOR) by suppressing Sucrose non-fermenting-1-related protein kinase 1 (SnRK1). Purified SnRK1α1 suppresses TOR activity, and T6P reverses this inhibition in a dose-dependent manner. IP-TOR incubated with SnRK1α1 alone or with GRIK1 and EIF4EBP1 substrate ± T6P (0.1–1 mM). TOR activities were quantified at right. Similar results were shown with S6K1 (Supplementary Fig. 8).
bioRxiv Plant Bio@biorxiv-plants.bsky.social · 8mo ago

Trehalose 6-phosphate activates Target of Rapamycin in plants https://www.biorxiv.org/content/10.64898/2025.12.11.693803v1

Ryo Yokoyama@yokoyama-ryo.bsky.social · 2y ago

Cytochrome c levels link mitochondrial function to plant growth and stress responses through changes in SnRK1 pathway activity onlinelibrary.wiley.com/doi/10.1111/... @theplantjournal.bsky.social

Cytochrome c levels link mitochondrial function to plant growth and stress responses through changes in SnRK1 pathway activity

Mitochondria are signalling hubs that integrate and transmit biological information to affect different cellular processes. We show that changes in the mitochondrial electron transport chain componen...

onlinelibrary.wiley.com