Enhanced Stress Resistance Research Articles

Rubidium Chloride Increases Life Span Through an AMPK/FOXO-Dependent Pathway in Caenorhabditis elegans.

AMP-activated protein kinase (AMPK) is involved in life-span maintenance, stress responses, and germ cell cycle arrest upon dauer entry. AMPK is currently considered a promising target for preventing age-related diseases. Rubidium is one of the trace elements in the human body. As early as the 1970s, rubidium chloride (RbCl) was reported to have neuroprotective effects. In this work, we report the antiaging effect of RbCl in Caenorhabditis elegans. Specifically, we reveal that (a) RbCl does increase the life span and enhance stress resistance in C. elegans without disturbing their fecundity. (b) RbCl induces superoxide dismutase expression, which is essential for its antiaging and antistress effect. (c) AAK-2 and DAF-16 are essential to the antiaging efficacy of RbCl, and RbCl can promote DAF-16 translocating into the nucleus, suggesting that RbCl delays aging by regulating the AMPK/FOXO pathway. RbCl can be a promising agent against aging-related diseases.

The Role of Plant-Associated Bacteria, Fungi, and Viruses in Drought Stress Mitigation.

Drought stress is an alarming constraint to plant growth, development, and productivity worldwide. However, plant-associated bacteria, fungi, and viruses can enhance stress resistance and cope with the negative impacts of drought through the induction of various mechanisms, which involve plant biochemical and physiological changes. These mechanisms include osmotic adjustment, antioxidant enzyme enhancement, modification in phytohormonal levels, biofilm production, increased water and nutrient uptake as well as increased gas exchange and water use efficiency. Production of microbial volatile organic compounds (mVOCs) and induction of stress-responsive genes by microbes also play a crucial role in the acquisition of drought tolerance. This review offers a unique exploration of the role of plant-associated microorganisms—plant growth promoting rhizobacteria and mycorrhizae, viruses, and their interactions—in the plant microbiome (or phytobiome) as a whole and their modes of action that mitigate plant drought stress.

Identification of Tropical Plant Extracts That Extend Yeast Chronological Life Span.

Certain plant extracts (PEs) contain bioactive compounds that have antioxidant and lifespan-extending activities on organisms. These PEs play different roles in cellular processes, such as enhancing stress resistance and modulating longevity-defined signaling pathways that contribute to longevity. Here, we report the discovery of PEs that extended chronological life span (CLS) in budding yeast from a screen of 222 PEs. We identified two PEs, the leaf extracts of Manihot esculenta and Wodyetia bifurcata that extended CLS in a dose-dependent manner. The CLS-extending PEs also conferred oxidative stress tolerance, suggesting that these PEs might extend yeast CLS through the upregulation of stress response pathways.

ZmCCT regulates photoperiod-dependent flowering and response to stresses in maize

BackgroundAppropriate flowering time is very important to the success of modern agriculture. Maize (Zea mays L.) is a major cereal crop, originated in tropical areas, with photoperiod sensitivity. Which is an important obstacle to the utilization of tropical/subtropical germplasm resources in temperate regions. However, the study on the regulation mechanism of photoperiod sensitivity of maize is still in the early stage. Although it has been previously reported that ZmCCT is involved in the photoperiod response and delays maize flowering time under long-day conditions, the underlying mechanism remains unclear.ResultsHere, we showed that ZmCCT overexpression delays flowering time and confers maize drought tolerance under LD conditions. Implementing the Gal4-LexA/UAS system identified that ZmCCT has a transcriptional inhibitory activity, while the yeast system showed that ZmCCT has a transcriptional activation activity. DAP-Seq analysis and EMSA indicated that ZmCCT mainly binds to promoters containing the novel motifs CAAAAATC and AAATGGTC. DAP-Seq and RNA-Seq analysis showed that ZmCCT could directly repress the expression of ZmPRR5 and ZmCOL9, and promote the expression of ZmRVE6 to delay flowering under long-day conditions. Moreover, we also demonstrated that ZmCCT directly binds to the promoters of ZmHY5, ZmMPK3, ZmVOZ1 and ZmARR16 and promotes the expression of ZmHY5 and ZmMPK3, but represses ZmVOZ1 and ZmARR16 to enhance stress resistance. Additionally, ZmCCT regulates a set of genes associated with plant development.ConclusionsZmCCT has dual functions in regulating maize flowering time and stress response under LD conditions. ZmCCT negatively regulates flowering time and enhances maize drought tolerance under LD conditions. ZmCCT represses most flowering time genes to delay flowering while promotes most stress response genes to enhance stress tolerance. Our data contribute to a comprehensive understanding of the regulatory mechanism of ZmCCT in controlling maize flowering time and stress response.

Hormonal Regulation of Diapause and Development in Nematodes, Insects, and Fishes

Diapause is a state of developmental arrest adopted in response to or in anticipation of environmental conditions that are unfavorable for growth. In many cases, diapause is facultative, such that animals may undergo either a diapause or a non-diapause developmental trajectory, depending on environmental cues. Diapause is characterized by enhanced stress resistance, reduced metabolism, and increased longevity. The ability to postpone reproduction until suitable conditions are found is important to the survival of many animals, and both vertebrate and invertebrate species can undergo diapause. The decision to enter diapause occurs at the level of the whole animal, and thus hormonal signaling pathways are common regulators of the diapause decision. Unlike other types of developmental arrest, diapause is programmed, such that the diapause developmental trajectory includes a pre-diapause preparatory phase, diapause itself, recovery from diapause, and post-diapause development. Therefore, developmental pathways are profoundly affected by diapause. Here, I review two conserved hormonal pathways, insulin/IGF signaling (IIS) and nuclear hormone receptor signaling (NHR), and their role in regulating diapause across three animal phyla. Specifically, the species reviewed are Austrofundulus limnaeus and Nothobranchius furzeri annual killifishes, Caenorhabditis elegans nematodes, and insect species including Drosophila melanogaster, Culex pipiens, and Bombyx mori. In addition, the developmental changes that occur as a result of diapause are discussed, with a focus on how IIS and NHR pathways interact with core developmental pathways in C. elegans larvae that undergo diapause.

The sex peptide receptor in the Asian gypsy moth, Lymantria dispar, is involved in development and stress resistance

The G protein-coupled receptor (GPCR) regulates downstream genes by binding to a heterotrimeric G protein. However, the function of sex peptide receptor (SPR) in lepidopteran species is mostly unknown. Understanding the physiological functions of SPR in insects is essential for exploring new insecticidal targets. In the present study, the functions of an SPR in Lymantria dispar (Asian gypsy moth; LdSPR) were investigated. The expression of LdSPR was the highest in the 6th instar larval stage, and there was a large difference in expression between male and female adults. After LdSPR gene silencing, L. dispar larvae showed increased sensitivity to high temperature, starvation, and oxidative stress, indicating that LdSPR enhances stress resistance. These results enrich our knowledge of the function of the insect SPRs, which will lead to a better understanding of other insect GPCR family members and the identification of new targets for the development of environmentally friendly pesticides.

Streptomyces Application Triggers Reassembly and Optimization of the Rhizosphere Microbiome of Cucumber

Streptomyces partum Act12 and Streptomyces roche D74 are biocontrol strains that can promote plant growth and enhance stress resistance in different crops. However, their effects on the rhizosphere microbiome and the role of the reassembled microbiome in plant growth promotion and stress resistance enhancement remain unclear. This study investigated the variation in the rhizosphere microbiome induced by Streptomyces application through a cucumber (Cucumis sativus L. cv. “Youliang”) pot experiment. The bacterial and fungal communities of rhizosphere soils inoculated with and without Streptomyces were, respectively, compared based on 16S rRNA and internal transcribed spacer rRNA gene sequences. Following Streptomyces application, the bacterial alpha diversity increased significantly, while the fungal alpha diversity exhibited the opposite trend. The bacterial and fungal communities’ compositions clearly shifted in the inoculated soil. Compared with the uninoculated control, the relative abundance of the genus Streptomyces increased by 68.3%, and the bacterial co-occurrence network in the rhizosphere soil was enriched significantly. The relative abundance of bacteria associated with nitrogen fixation was increased by 7.5% following Streptomyces application. Based on the results of this study, we conclude that the application of Streptomyces Act12 and D74 can be used to reassemble and optimize the rhizosphere microbiome of cucumber, which is conducive to plant survival.

GroEL protein from the potential biocontrol agent Rhodopseudomonas palustris enhances resistance to rice blast disease.

GroEL, which is a chaperone, plays a key role in maintaining protein homeostasis and, among other functions, serves to prevent protein misfolding and aggregation. In addition, the GroEL protein also has a significant effect on enhancing plant resistance and inhibiting plant diseases. However, the function of the GroEL protein in the inhibition of rice blast remains unknown. Field experiment results show that photosynthetic bacteria PSB-06 have a good control effect on Magnaporthe oryzae. PSB-06 also can promote rice growth and enhance stress resistance. A GroEL protein which was separated and purified from photosynthetic bacteria had a significant antagonistic effect on appressorial formation and pathogenicity of Magnaporthe oryzae, meanwhile transcriptional analysis demonstrated that the GroEL protein could improve the expression of defense gene of rice. Our results show that the photosynthetic bacteria Rhodopseudomonas palustris significantly controls rice blast disease. Its action involves an extracellular GroEL protein, which inhibits appressoria formation, antagonizes the pathogenicity of Magnaporthe oryzae and promotes a host defense response. The research results provide evidence of the potential of this photosynthetic bacterium as a biocontrol agent at least for rice blast control. © 2021 Society of Chemical Industry.

The Potential of Calorie Restriction and Calorie Restriction Mimetics in Delaying Aging: Focus on Experimental Models.

Aging is a biological process determined by multiple cellular mechanisms, such as genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication, that ultimately concur in the functional decline of the individual. The evidence that the old population is steadily increasing and will triplicate in the next 50 years, together with the fact the elderlies are more prone to develop pathologies such as cancer, diabetes, and degenerative disorders, stimulates an important effort in finding specific countermeasures. Calorie restriction (CR) has been demonstrated to modulate nutrient sensing mechanisms, inducing a better metabolic profile, enhanced stress resistance, reduced oxidative stress, and improved inflammatory response. Therefore, CR and CR-mimetics have been suggested as powerful means to slow aging and extend healthy life-span in experimental models and humans. Taking into consideration the difficulties and ethical issues in performing aging research and testing anti-aging interventions in humans, researchers initially need to work with experimental models. The present review reports the major experimental models utilized in the study of CR and CR-mimetics, highlighting their application in the laboratory routine, and their translation to human research.

Antioxidant capacity of flavonoids from Folium Artemisiae Argyi and the molecular mechanism in Caenorhabditis elegans

Ethnopharmacological relevanceFolium Artemisiae Argyi (FAA) is one kind of Chinese herbal medicine with a long history. It has widespread pharmacological activities such as antibacterial, anti-inflammatory, antioxidative, and hemostatic, among others. FAA is traditionally used for the treatment of eczema, respiratory diseases and gynecological diseases for hundreds of years. Flavonoids are reported as the main components of them. Recent studies focused on the antioxidant effect of its flavonoids in vitro, while few studies focused on the antioxidant effect in vivo, and the underlying mechanisms have not yet been elucidated. Aim of the studyThe aim of this study was to evaluate the antioxidant activity of Folium Artemisia Argyi flavonoids (FAAF) and explore its possible molecular mechanism in Caenorhabditis elegans. The research and development of its medicinal value will beneficial to the resource utilization of FAA. Materials and methodsFirstly, FAAF was prepared, purified and then qualitatively and quantitatively analyzed using LC-DAD-MS. Then, 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), hydroxyl radical and ferric reducing antioxidant power (FRAP) assays were applied to investigate the antioxidant effect of FAAF in vitro. Meanwhile, a stress resistance assay was carried out to evaluate the antioxidant effect of FAAF in vivo. Moreover, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and reactive oxygen species (ROS) accumulation were determined to ascertain whether FAAF can increase the oxidant defense system of nematodes and reduce the accumulation of ROS. Lipofuscin and protein carbonylation assays were employed to test whether FAAF can increase the antioxidant capacity of nematodes to resist the growth health indicators related to antioxidation. At last, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to evaluate the expression of genes related to antioxidation. The expression of green fluorescent protein (GFP) was further investigated using a fluorescence microscope in transgenic strains (SOD-3::GFP, GST-4::GFP, and HSP-16.2::GFP). ResultsFAAF exhibited a strong antioxidant capacity and enhanced stress resistance in C. elegans. FAAF reduced ROS accumulation and improved the antioxidant defense system under acute stress. Moreover, FAAF prevented the accumulation of lipofuscin and protein carbonylation in C. elegans. FAAF also upregulated the gene expression levels of hsp-16.2, gst-4, sod-3, skn-1, daf-16, ctl-2, hsf-1 and increased SOD-3::GFP and GST-4::GFP expression. ConclusionThese results demonstrated that FAAF exerted antioxidant activity in C. elegans. It was perhaps regulated by the insulin/insulin-like growth factor-1(IGF-1) signaling pathway.

Effects and mechanisms of nitrogen application on stress resistance of Chinese materia medica

Nitrogen fertilizers play an important role in the regulation of plant stress resistance. Impacts of nitrogen fertilizers on abiotic stress resistance and biotic stress resistance of Chinese materia medica(CMM) were summarized in this study. Adequate nitrogen application improves the abiotic stress resistance and weed resistance of CMM, however adverse effect appears when excess nitrogen is used. Generally, pest resistance decreases along with nitrogen deposition, while effects of nitrogen application on disease resistance vary with different diseases. Mechanisms underlying the impact of nitrogen fertilizers on plant stress resistance were also elucidated in this study from three aspects including physical defense mechanisms, biochemistry mechanisms and molecular defense mechanisms. Nitrogen availability modulates physical barrier of CMM like plant growth, formation of lignin and wax cuticle, and density of stomata. Growth of CMM promoted by nitrogen fertilizer may cause some decrease in pest resistance of CMM due to an increase in hiding places for pest along with plant growth. High ambient humidity caused by excessive plant growth facilitates the growth and development of CMM pathogen. Nitrogen application can also interfere with the accumulation of lignin in CMM which makes CMM more vulnerable to pest and pathogen attack. Stomatal closing delays due to nitrogen application is also a causal factor of increasing pathogen infection after nitrogen deposition. Biochemical defenses of plants are mainly achieved through nutrient elements, secondary metabolites, defense-related enzymes and proteins. Nutritional level of CMM and various antioxidant enzymes and resistance-related protein activities are elevated along with nitrogen deposition. These antioxidant enzymes can reduce the damage of reactive oxygen species content produced by plant in response to adversity and therefore enhance stress resistance of CMM. Researches showed that nitrogen application could also cause an increase in nitrogen-containing secondary metabolites content and a decrease in non-nitrogen-containing secondary metabolites content respectively. Nitrogen-mediated molecular defense mechanisms includes multiple plant hormones and nitric oxide signals. Plant hormones related to plant defense like salicylic acid, jasmonic acid and abscisic acid can be modulated by nitrogen application. Negative effect of nitrogen deposition was found on salicylic acid accumulation and the expression of related plant disease resistance genes. However, jasmonic acid level can be elevated by nitrogen. Nitric oxide signals constitute an important part of nitrogen mediated defense mechanisms. Nitric oxide signaling is related to many aspects of plant immunity. The roles of nitrogen fertilizers in CMM stress resistance are complex and may vary with different CMM varieties and environments. Further studies are urgently needed to provide a comprehensive understanding of how to improve stress resistance of CMM by using fertilizers.

Weaning strategies affect larval performance in yellowfin seabream (Acanthopagrus latus)

A 30-day study was carried out to determine the influence of different weaning strategies (WS) on growth and survival rates, stress resistance, digestive enzyme activities and whole body fatty acid profiles in yellowfin seabream (Acanthopagrus latus) larvae. Thus, eight WS were designed by combining live foods (LF) (rotifers and Artemia) and a microdiet (MD) (Gemma Micro™, Skretting). In the control group (100 LF), larvae were fed only LF (100%), including enriched rotifers (from 2 to 20 days post hatching, dph) and Artemia (nauplii + enriched metanauplii, from 18 to 30 dph). The other treatments were based on different proportions of LF with the MD: 75LF-25MD, 50LF-50MD, 25LF-75MD and 100 MD in which 25, 50, 75 and 100% of LF that applied in the control group were replaced with a fixed ration of MD, respectively. In addition, for determining the appropriate time of weaning, three WS were applied including: sudden weaning (SW): larvae were weaned on to MD with only rotifer from 2 to 5 days post hatch (dph); early weaning (EW): larvae were weaned on to MD with only rotifer from 2 to 14 dah and late weaning (LW): larvae were weaned on to MD with rotifer (from 2 to 14 dph) and Artemia nauplii (from 12 to 20 dph). Larvae were hand-fed with the MD hourly from 08:00 h to 18:00 h (11 times a day). Results showed that the lowest survival rates were found among larvae from 100MD (1.5%) and SW (1.9%) groups, whereas the highest survival rates were found in larvae from 100LF (31.0 ± 1.7%), 75LF-25MD (34.7 ± 4.5%) and 50LF-50MD (36.2 ± 4.0%). Larvae from the 50LF-50MD group showed the highest resistance against air exposure (70.0%) and osmotic stress (100.0%) challenges. At the end of the trial, larvae from 100LF, 75LF-25MD, 50LF-50MD and LW groups showed higher growth performance than the other groups. At 30 dph, larvae from the LW group had the highest level of alkaline phosphatase to leucine-alanine peptidase ratio, while those from the 100MD, SW and EW treatments showed the lowest ones. The fatty acid profile of larvae reflected that of the diet. In particular, larvae from 100MD and SW groups had generally lower levels of n-3 long chain polyunsaturated fatty acids compared to the other treatments. In conclusion, results of the present study indicated the time of weaning and proportion of LF and MD remarkably affect larvae performance in terms of growth, survival, digestive function and stress tolerance. In addition, the replacement of LF with MD up to 50% after mouth opening of larvae neither have detrimental effects on growth, survival and digestive enzymes activities, meanwhile enhanced stress resistance of A. latus larvae.

Evolution, expression and functional analysis of cultivated allotetraploid cotton DIR genes

BackgroundDirigent (DIR) proteins mediate regioselectivity and stereoselectivity during lignan biosynthesis and are also involved in lignin, gossypol and pterocarpan biosynthesis. This gene family plays a vital role in enhancing stress resistance and in secondary cell-wall development, but systematical understanding is lacking in cotton.ResultsIn this study, 107 GbDIRs and 107 GhDIRs were identified in Gossypium barbadense and Gossypium hirsutum, respectively. Most of these genes have a classical gene structure without intron and encode proteins containing a signal peptide. Phylogenetic analysis showed that cotton DIR genes were classified into four distinct subfamilies (a, b/d, e, and f). Of these groups, DIR-a and DIR-e were evolutionarily conserved, and segmental and tandem duplications contributed equally to their formation. In contrast, DIR-b/d mainly expanded by recent tandem duplications, accompanying with a number of gene clusters. With the rapid evolution, DIR-b/d-III was a Gossypium-specific clade involved in atropselective synthesis of gossypol. RNA-seq data highlighted GhDIRs in response to Verticillium dahliae infection and suggested that DIR gene family could confer Verticillium wilt resistance. We also identified candidate DIR genes related to fiber development in G. barbadense and G. hirsutum and revealed their differential expression. To further determine the involvement of DIR genes in fiber development, we overexpressed a fiber length-related gene GbDIR78 in Arabidopsis and validated its function in trichomes and hypocotyls.ConclusionsThese findings contribute novel insights towards the evolution of DIR gene family and provide valuable information for further understanding the roles of DIR genes in cotton fiber development as well as in stress responses.

Sulforaphane promotes C. elegans longevity and healthspan via DAF-16/DAF-2 insulin/IGF-1 signaling.

The broccoli-derived isothiocyanate sulforaphane inhibits inflammation, oxidative stress and cancer, but its effect on healthspan and longevity are unclear. We used the C. elegans nematode model and fed the wildtype and 9 mutant strains ±sulforaphane. The lifespan, phenotype, pharyngeal pumping, mobility, lipofuscin accumulation, and RNA and protein expression of the nematodes were assessed by using Kaplan-Meier survival analysis, in vivo live imaging, fluorescence microscopy, and qRT-PCR. Sulforaphane increased the lifespan and promoted a health-related phenotype by increasing mobility, appetite and food intake and reducing lipofuscin accumulation. Mechanistically, sulforaphane inhibited DAF-2-mediated insulin/insulin-like growth factor signaling and its downstream targets AGE-1, AKT-1/AKT-2. This was associated with increased nuclear translocation of the FOXO transcription factor homolog DAF-16. In turn, the target genes sod-3, mtl-1 and gst-4, known to enhance stress resistance and lifespan, were upregulated. These results indicate that sulforaphane prolongs the lifespan and healthspan of C. elegans through insulin/IGF-1 signaling. Our results provide the basis for a nutritional sulforaphane-enriched strategy for the promotion of healthy aging and disease prevention.

Polygonum multiflorumThunb extract extended the lifespan and healthspan ofCaenorhabditis elegans viaDAF-16/SIR-2.1/SKN-1

Polygonum multiflorum Thunb (PMT), as a traditional Chinese herbal medicine, has been widely used in the prevention and treatment of aging-related diseases, including Alzheimer's disease, Parkinson's disease, hyperlipidemia, atherosclerosis and inflammation. However, the effect of PMT on the lifespan and its molecular mechanisms are still unclear. Here we found that 60% ethanol refined fraction (PMT-E) of Polygonum multiflorum Thunb at 50 μg mL-1, which contained two main bioactive compounds, 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG) and emodin-8-O-β-D-glucoside (EG), could significantly increase the mean lifespan by 19.82%, delay the age-related decline of phenotypes, enhance stress resistance and reduce ROS accumulation in Caenorhabditis elegans. Moreover, we also found that the mitochondrial membrane potential (ΔΨ) and ATP content of worms treated with 50 μg mL-1 PMT-E were obviously improved. Further mechanistic studies revealed that DAF-16, SIR-2.1 and SKN-1 transcription factors were required for PMT-E-mediated lifespan extension. Finally, we found that PMT-E could significantly inhibit the toxicity induced by β-amyloid (Aβ) in Aβ transgenic worms. Altogether, these findings laid the foundation for the use of Polygonum multiflorum Thunb to treat aging and age-related diseases.

Ursolic acid enhances stress resistance, reduces ROS accumulation and prolongs life span in C. elegans serotonin-deficient mutants.

Depression and anxiety disorders contribute to the global disease burden. Ursolic acid (UA), a natural compound present in many vegetables, fruits and medicinal plants, was tested in vivo for its effect on (1) enhancing resistance to stress and (2) its effect on life span. The compound was tested for its antioxidant activity in C. elegans. Stress resistance was tested in the heat and osmotic stress assay. Additionally, the influence on normal life span was examined. RT-PCR was used to assess possible serotonin targets. UA prolonged the life span of C. elegans. Additionally, UA significantly lowered reactive oxygen species (ROS). Molecular docking studies, PCR analysis and microscale thermophoresis (MST) supported the results that UA acts through serotonin receptors to enhance stress resistance. Considering the urgent need for new and safe medications in the treatment of depression and anxiety disorders, our results indicate that UA may be a promising new drug candidate.

Mitochondrial transplantation therapy inhibit carbon tetrachloride-induced liver injury through scavenging free radicals and protecting hepatocytes.

Carbon tetrachloride (CCl4)‐induced liver injury is predominantly caused by free radicals, in which mitochondrial function of hepatocytes is impaired, accompanying with the production of ROS and decreased ATP energy supply in animals intoxicated with CCl4. Here we explored a novel therapeutic approach, mitochondrial transplantation therapy, for treating the liver injury. The results showed that mitochondria entered hepatocytes through macropinocytosis pathway, and thereby cell viability was recovered in a concentration‐dependent manner. Mitochondrial therapy could increase ATP supply and reduce free radical damage. In liver injury model of mice, mitochondrial therapy significantly improved liver function and prevented tissue fibrogenesis. Transcriptomic data revealed that mitochondrial unfold protein response (UPRmt), a protective transcriptional response of mitochondria‐to‐nuclear retrograde signaling, would be triggered after mitochondrial administration. Then the anti‐oxidant genes were up‐regulated to scavenge free radicals. The mitochondrial function was rehabilitated through the transcriptional activation of respiratory chain enzyme and mitophage‐associated genes. The protective response re‐balanced the cellular homeostasis, and eventually enhanced stress resistance that is linked to cell survival. The efficacy of mitochondrial transplantation therapy in the animals would suggest a novel approach for treating liver injury caused by toxins.

SUMO promotes longevity and maintains mitochondrial homeostasis during ageing in Caenorhabditis elegans

The insulin/IGF signalling pathway impacts lifespan across distant taxa, by controlling the activity of nodal transcription factors. In the nematode Caenorhabditis elegans, the transcription regulators DAF-16/FOXO and SKN-1/Nrf function to promote longevity under conditions of low insulin/IGF signalling and stress. The activity and subcellular localization of both DAF-16 and SKN-1 is further modulated by specific posttranslational modifications, such as phosphorylation and ubiquitination. Here, we show that ageing elicits a marked increase of SUMO levels in C. elegans. In turn, SUMO fine-tunes DAF-16 and SKN-1 activity in specific C. elegans somatic tissues, to enhance stress resistance. SUMOylation of DAF-16 modulates mitochondrial homeostasis by interfering with mitochondrial dynamics and mitophagy. Our findings reveal that SUMO is an important determinant of lifespan, and provide novel insight, relevant to the complexity of the signalling mechanisms that influence gene expression to govern organismal survival in metazoans.

Loss of rice PARAQUAT TOLERANCE 3 confers enhanced resistance to abiotic stresses and increases grain yield in field.

Plants frequently suffer from environmental stresses in nature and have evolved sophisticated and efficient mechanisms to cope with the stresses. To balance between growth and stress response, plants are equipped with efficient means to switch off the activated stress responses when stresses diminish. We previously revealed such an off-switch mechanism conferred by Arabidopsis PARAQUAT TOLERANCE 3 (AtPQT3) encoding an E3 ubiquitin ligase, knockout of which significantly enhances resistance to abiotic stresses. To explore whether the rice homologue OsPQT3 is functionally conserved, we generated three knockout mutants with CRISPR-Cas9 technology. The OsPQT3 knockout mutants (ospqt3) display enhanced resistance to oxidative and salt stress with elevated expression of OsGPX1, OsAPX1 and OsSOD1. More importantly, the ospqt3 mutants show significantly enhanced agronomic performance with higher yield compared with the wild type under salt stress in greenhouse as well as in field conditions. We further showed that OsPQT3 expression rapidly decreased in response to oxidative and other abiotic stresses as AtPQT3 does. Taken together, these results show that OsPQT3 is functionally well conserved in rice as an off-switch in stress response as AtPQT3 in Arabidopsis. Therefore, PQT3 locus provides a promising candidate for crop improvement with enhanced stress resistance by gene editing technology.

Piquiá Shells (Caryocar villosum): A Fruit by-Product with Antioxidant and Antiaging Properties in Caenorhabditis elegans.

In a context of rising demand for sustainable antiaging interventions, fruit processing by-products are a promising source of bioactive compounds for the production of antiaging dietary supplements. Piquiá (Caryocar villosum) is a native Amazonian fruit consisting of 65% nonedible shells. In the present study, the phytochemical profile of a hydroalcoholic extract of piquiá shells (CV) was characterized by LC-MS/MS analysis. Its antioxidant and antiaging activities were investigated using the nematode Caenorhabditis elegans as an in vivo model. CV is mainly composed by hydrolysable tannins and triterpenoid saponins. The extract enhanced stress resistance of wild-type and mutant worms by reducing the intracellular levels of reactive oxygen species (ROS) and by increasing their survival against a lethal dose of the prooxidant juglone. These effects involved the upregulation of sod-3 and downregulation of gst-4 and hsp-16.2, studied through the GFP fluorescent reporter intensity and at the transcriptional level by qRT-PCR analysis. CV extended the lifespan of wild-type worms in a DAF-16/FoxO- and SKN-1/Nrf-dependent manner. Taken together, our findings indicate piquiá shells as potential candidates for nutraceutical applications. Further studies are needed to validate the relevance of our findings to antiaging interventions in humans.