Summary: Sugar deficiency is the persistent challenge for plants during development. Trehalose‐6‐phosphate (T6P) is recognized as a key regulator in balancing plant sugar homeostasis. However, the underlying mechanisms by which sugar starvation limits plant development are unclear. Here, a basic helix–loop–helix (bHLH) transcription factor (OsbHLH111) was named starvation‐associated growth inhibitor 1 (OsSGI1) and the focus is on the sugar shortage of rice. The transcript and protein levels of OsSGI1 were markedly increased during sugar starvation. The knockout mutants sgi1‐1/2/3 exhibited increased grain size and promoted seed germination and vegetative growth, which were opposite to those of overexpression lines. The direct binding of OsSGI1 to sucrose non‐fermenting‐1 (SNF1)‐related protein kinase 1a (OsSnRK1a) was enhanced during sugar shortage. Subsequently, OsSnRK1a‐dependent phosphorylation of OsSGI1 enhanced the direct binding to the E‐box of trehalose 6‐phosphate phosphatase 7 (OsTPP7) promoter, thus rose the transcription inhibition on OsTPP7, then elevated trehalose 6‐phosphate (Tre6P) content but decreased sucrose content. Meanwhile, OsSnRK1a degraded phosphorylated‐OsSGI1 by proteasome pathway to prevent the cumulative toxicity of OsSGI1. Overall, we established the OsSGI1‐OsTPP7‐Tre6P loop with OsSnRK1a as center and OsSGI1 as forward, which is activated by sugar starvation to regulate sugar homeostasis and thus inhibits rice growth.

Refractory MRSA infections seriously threaten human health, which compromises antibiotic efficacy. Although phototherapy has exhibited great feasibility in the fight against drug-resistant pathogens, a single-modal therapeutic agent without targeted performance has resulted in low drug utilization and obvious side effects. Herein, near-infrared (NIR) light-triggered theranostic nanoparticles (NDIA@PEG-Ce6/B NPs) were prepared by employing naphthalene diimide derivative NDIA as a photothermal agent, PEGylated chlorin e6 (PEG-Ce6) as a photosensitizer and PEGylated phenylboronic acid (PEG-B) as a bacteria-targeting agent. Upon laser irradiation, the singlet oxygen produced by Ce6 can efficiently kill bacteria through photodynamic therapy. Moreover, the fluorescence emission of Ce6 can be absorbed by the photothermal agent NDIA with a fluorescence resonance energy transfer (FRET) efficiency of 78% to reinforce the photothermal effect of NDIA, and the photothermal conversion efficiency of NDIA@PEG-Ce6/B NPs was up to 49.7%. In vitro and in vivo antibacterial experiments indicated that NDIA@PEG-Ce6/B NPs could targeted assembly and effectively destroy multidrug-resistant bacteria through synergistic photothermal and photodynamic therapy with 99.999% antibacterial efficacy under NIR light illumination. The study provides a nanosystem for the antibacterial treatment of synergistic photodynamic and photothermal therapy for subcutaneous abscesses, as well as a novel FRET strategy for further design of light-triggered antibacterial nanoplatforms.

Trehalose is the major “blood sugar” of insects and it plays a crucial role in energy supply and as a stress protectant. The hydrolysis of trehalose occurs only under the enzymatic control of trehalase (Treh), which plays important roles in growth and development, energy supply, chitin biosynthesis, and abiotic stress responses. Previous reports have revealed that the vital hormone 20-hydroxyecdysone (20E) regulates Treh, but the detailed mechanism underlying 20E regulating Treh remains unclear. In this study, we investigated the function of HaTreh1 in Helicoverpa armigera larvae. The results showed that the transcript levels and enzymatic activity of HaTreh1 were elevated during molting and metamorphosis stages in the epidermis, midgut, and fat body, and that 20E upregulated the transcript levels of HaTreh1 through the classical nuclear receptor complex EcR-B1/USP1. HaTreh1 is a mitochondria protein. We also found that knockdown of HaTreh1 in the fifth- or sixth-instar larvae resulted in weight loss and increased mortality. Yeast two-hybrid, coimmunoprecipitation, and glutathione-S-transferase (GST) pull-down experiments demonstrated that HaTreh1 bound with ATP synthase subunit alpha (HaATPs-α) and that this binding increased under 20E treatment. In addition, 20E enhanced the transcript level of HaATPs-α and ATP content. Finally, the knockdown of HaTreh1 or HaATPs-α decreased the induction effect of 20E on ATP content. Altogether, these findings demonstrate that 20E controls ATP production by up-regulating the binding of HaTreh1 to HaATPs-α in H. armigera.