A NIR fluorescent probe for imaging thiophenol in the living system and revealing thiophenol-induced oxidative stress

Thiophenol(PhSH)is an important raw material for organic synthesis,while its high toxicity to organisms makes it an environmental pollutant.Therefore,it is crucial to accurately detect PhSH and explore its metabolic process in the living system.Herein,a near-infrared(NIR)fluorescent probe TEM-FB was developed for sensing PhSH with a turn-on fluorescent signal at 719nm and a large Stokes shift(198 nm)based on generating the intramolecular charge transfer(ICT)process.TEM-FB shows high specificity and significant sensitivity towards PhSH(detection limit:10 nmol/L)via the aromatic nucleophilic substitution mechanism.Furthermore,it was successfully applied to image PhSH in multiple cell lines and in zebrafish.Notably,we revealed the oxidative stress process caused by PhSH and demonstrated that the hydrogen peroxide(H_(2)O_(2))in cells would alleviate the poisonousness from exogenous PhSH for the first time.This work provides a promising bioimaging tool for monitoring PhSH in living systems and visualizing the process of oxidative stress induced by PhSH.

Robust chromophore-integrated MOFs as highly visible-white-light active and tunable size-selective photocatalysts towards benzothiazoles

Visible-light heterogeneous photocatalyst with high activity and selectivity is crucial for the development of organic transformations, but remains a formidable challenge. Herein, a simple and effective strategy was developed to integrate tetrazine moiety, a visible light active unit, into robust metal-organic frameworks(2D MOF-1(M), M = Co, Mn, Zn, and 3D MOF-2(Co)). MOF-1 series are isomorphous 2D porous frameworks, and MOF-2(Co) displays 3D porous framework. Interestingly, benefiting from the oxidative active species of O_(2)·-, these MOFs all exhibit obviously highly enhanced photocatalytic activities toward the straightforward condensation of o-aminothiophenol and aromatic aldehydes at room temperature in Et OH under visible-white-light irradiation. Notably, compared to 3D MOF, the 2D layered MOF-1(Co) exhibited more excellent catalytic activity with a wide range of substrates possessing preeminent tolerance of steric hindrance. Most impressively, MOF-1(Co) can be recycled at least five times without significant loss of catalytic activity or crystallinity, exhibiting excellent stability and reusability. This study sheds light on the wide-ranging prospects of visible light active 2D MOFs as green photocatalysts for the preparation of fine chemicals.

FHY3 and FAR1 Integrate Light Signals with the miR156-SPL Module-Mediated Aging Pathway to Regulate Arabidopsis Flowering

In response to competition for light from their neighbors,shade-intolerant plants flower precociously to ensure reproductive success and survival.However,the molecular mechanisms underlying this key developmental switch are not well understood.Here,we show that a pair of Arabidopsis transcription factors essential for phytochrome A signaling,FAR-RED ELONGATED HYPOCOTYL3(FHY3)and FAR-RED IMPAIRED RESPONSE1(FAR1),regulate flowering time by integrating environmental light signals with the miR156-SPL module-mediated aging pathway.We found that FHY3 and FAR1 directly interact with three flowering-promoting SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE(SPL)transcription factors,SPL3,SPL4,and SPL5,and inhibit their binding to the promoters of several key flowering regulatory genes,including FRUITFUL(FUL),LEAFY(LFY),APETALA1(AP1),and MIR172C,thus downregulating their transcript levels and delaying flowering.Under simulated shade conditions,levels of SPL3/4/5 proteins increase,whereas levels of FHY3 and FAR1 proteins decline,thus releasing SPL3/4/5 from FHY3/FAR1 inhibition to allow activation of FUL,LFY,AP1,and MIR172C and,consequently,early flowering.Taken together,these results unravel a novel mechanism whereby plants regulate flowering time by integrating environmental cues(such as light conditions)and an internal developmental program(the miR156-SPL module-mediated aging pathway).