Designing and synthesizing nanomedicines with multi-modal tumor therapeutic capabilities is the key to cancer treatment.Herein,we prepared MICG nanoparticles(NPs)by assembling glucose oxidase(GOx)and indocyanine green...Designing and synthesizing nanomedicines with multi-modal tumor therapeutic capabilities is the key to cancer treatment.Herein,we prepared MICG nanoparticles(NPs)by assembling glucose oxidase(GOx)and indocyanine green(ICG)with manganese carbonate(MnCO_(3))NPs for starvation therapy cascaded chemodynamic therapy,enhanced phototherapy and immune activation.In MICG NPs,the GOx consumes intratumoral glucose resulting in starvation therapy,and simultaneously produces H_(2)O_(2)and decreases p H in tumor.The intensified acidic tumor environment promotes the decomposition of MnCO_(3)NPs to release Mn^(2+).The Mn^(2+)further catalyzes H_(2)O_(2)to generate hydroxyl radical for chemodynamic therapy.While ICG can generate singlet oxygen(^(1)O_(2))and heat to kill cancer cells through phototherapy mechanism.The hydroxyl radical and ^(1)O_(2) will further accelerate the oxidative stress,intensify immunogenic cell death,induce dendritic cell maturation,and thus activate systemic immunity.This work provides a new therapeutic platform for combining therapy of tumor.展开更多
The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflo...The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflow anaerobic biofilter(UAF)treating municipal wastewater was established.The performances of stable operation and recovery operation of UAF after long-term starvation(234 days)and the changes of microbial community structure were researched.By gradually reducing HRT from 10 h to 4 h,the UAF achieved the treatment performance of pre-starvation after only 50 days recovery operation,in which total COD and soluble COD removal efficiencies reached 66%and 69%,respectively,and the CH_(4) production rate was 0.21 L CH_(4)/g CODremoval.The recovery performance of UAF after long term starvation showed that the recovery sequence of three main anaerobic processes was hydrolytic acidification,hydrogen-acetate production and methanogenesis.High-throughput sequencing results indicated that dominant bacteria associated with hydrolytic acidification process changed from Moduliflexaceae and Trichococcus in stable operation stage to Trichococcus and Romboutsia in recovery stage.Besides,the dominant archaea changed from Methanosaeta(hydrotrophic methanogens)to Methanobacterium(acetotrophic methanogens),showing Methanobacterium was more resistant to starvation environment.Therefore,by using UAF for biological treatment of organic matter,even after a long period of starvation,the system would not be completely destroyed.Once it resumed operation,the treatment performance could be restored in a short period of time.展开更多
Copper-nickel alloys can suffer severe localized corrosion in marine environments containing sulfate-reducing bacteria(SRB),but the effect of SRB on the under-deposit corrosion of copper-nickel alloys is unknown.In th...Copper-nickel alloys can suffer severe localized corrosion in marine environments containing sulfate-reducing bacteria(SRB),but the effect of SRB on the under-deposit corrosion of copper-nickel alloys is unknown.In this work,the corrosion behavior of B10 copper-nickel alloy beneath a deposit caused by SRB with carbon source starvation in artificial seawater was studied based on electrochemical measurements and surface analysis.Results demonstrate that SRB with an organic carbon starvation can survive in artificial water but most SRB cells have died.The survived SRB cells can attach to the bare and deposit-covered B10 copper-nickel alloy,leading to the corrosion acceleration.Due to the limitation of organic carbon source,the pitting corrosion of B10 copper-nickel alloy caused by SRB is not serious.However,serious pitting corrosion of the deposit-covered B10 copper-nickel alloy can be found both in abiotic and biotic conditions,and the pitting corrosion and uniform corrosion are further accelerated by SRB.There is a galvanic effect between the bare and deposit-covered specimens in the presence of SRB in the early stage but the galvanic effect after 5 d of testing can be neglected due to the low OCP difference values.展开更多
Starvation in Karamoja remains one of human’s greatest infamies. Not blinking at this fact has resulted in solicitation for more permanent solutions. As part of this, the current study ventured into identifying indiv...Starvation in Karamoja remains one of human’s greatest infamies. Not blinking at this fact has resulted in solicitation for more permanent solutions. As part of this, the current study ventured into identifying individual and household factors that add stone to starvation among FHHs compared to MHHs. An Oaxaca Blinder Decomposition extended on Logistic regression was applied. The study found that income, education, age, land access and livestock ownership were factors behind the difference in starvation levels between male and female-headed households. The study suggests policies that promote gender equality, challenge traditional gender roles, and empower women economically and socially to significantly address barriers and create a supportive environment crucial for long-term solutions.展开更多
Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subseq...Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subsequently conducted under greenhouse conditions to further characterize APase activity and its isoform expression induced by P starvation. Results from the field experiment showed that there was a great genotypic variation for leaf APase activity among the tested soybean genotypes from different origins, and APase activity in many of the tested genotypes (about 60%) was generally increased in the treatment without P fertilizer addition. Results from the nutrient solution culture experiment showed that APase activity in all the eight tested genotypes was generally enhanced by P starvation. Six isoforms of APases were detected in isoelectric focusing gels with samples from both young and old leaves. The activity of all the six isoforms was increased by P starvation, but no new APase isoform was induced. Our results suggest that leaf APase activity could serve as an enzymatic indicator of P starvation for soybean; the increase in leaf APase activity under low P stress was mainly caused by the increase in the activity of existing isoforms but not by the induction of new isoforms.展开更多
Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate...Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate the molecular background of the adaptive mechanisms, the suppression subtractive hybridization (SSH) method was used to construct a rice phosphorus-starvation ( Pi-starvation) induced cDNA library. Through screening of the cDNA library and sequencing of the enriched cDNAs, 18 known genes and 47 novel genes were identified. The known genes are involved in different metabolic processes, including phosphate uptake and transport, signal transduction, protein synthesis and degradation, carbon metabolism and stress response. Northern analysis was performed to detect the expression patterns of some known genes and novel genes under different phosphorus levels. Different expression patterns of the selected genes were identified, which suggests that genes involved in different pathways may have different responses to Pi-starvation.展开更多
AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobari...AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.展开更多
To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcription...To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcriptional patterns of genes involved in sugar signaling pathways were determined in mutant rice exhibiting early leaf senescence and its wild type Zhefu 142.The effects of exogenous glucose or sucrose on the senescence of detached leaves under dark conditions were also investigated.Chlorophyll,soluble sugar,sucrose and fructose contents decreased,whereas electrolytic leakage and malondialdehyde levels increased in mutant leaves at the grain-filling stage.These results suggested that sugar starvation is positively correlated with the early leaf senescence of mutant plants.Detached leaf segments incubated in exogenous sugar solutions under dark conditions exhibited delayed senescence.The high expression of Hxk1 in leaves of mutant plants at the initial grain-filling stage suggested that Hxk1 is involved in the hexose-sensing process at the early stage of leaf senescence.The low expression levels of Hxk2 and Frk1 in the senescing leaves of mutant rice during the grain-filling stage are indicative of weakened hexose phosphorylation.In addition,the high expression levels of Su Sy1,Su Sy2 and Su Sy4 in leaves of mutant plants at the initial grain-filling stage are accompanied by the high transcript levels of SUT1,which favor sucrose translocation and remobilization from the early senescing leaves of mutant rice.The relatively reduced transcript levels of ch FBP,cy FBP,SPS1,SPS2 and SPS6 indicated that during the grain-filling stage,sucrose biosynthesis is weakened in the senescing leaves of mutant rice.展开更多
Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator g...Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator gene in Triticum aestivum, in mediating the N starvation adaptation in plants. Ta ARR1 harbors two conserved domains specified by plant ARR family members;subcellular localization analysis indicated its target onto nucleus after endoplasmic reticulum assortment. Ta ARR1 displayed modified expression upon the N starvation stressor, showing upregulated expression in roots and leaves over a 27-h N starvation treatment and whose induced transcripts were gradually recovered along with progression of the N recovery treatment. The tobacco lines overexpressing Ta ARR1 displayed improved low-N stress tolerance, displaying enlarged phenotype, increased biomass and N accumulation, and enhanced glutamine synthetase(GS) activities compared with wild type(WT) following the N starvation treatment. Expression analysis on genes encoding the nitrate transporter(NRT) and GS proteins in Nicotiana tabacum revealed that Nt NRT2.2 and Nt GS3 are upregulated in expression in the N-deprived transgenic lines, whose expression patterns were contrasted to other above family genes that were unaltered on transcripts between the transgenic lines and WT. Transgene analysis validated the function of Nt NRT2.2 and Nt GS3 in regulating N accumulation, GS activity, growth traits, and N use efficiency in plants. These results suggested the internal connection between the Ta ARR1-mediated N starvation tolerance and the modified transcription of distinct N acquisitionand assimilation-associated genes. Our investigation together indicates that Ta ARR1 is essential in plant N starvation adaptation due to the gene function in transcriptionally regulating distinct NRT and GS genes that affect plant N uptake and assimilation under the N starvation condition.展开更多
The effects of 60 day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallop Chlamys farreri were studied in laboratory from Oct. ...The effects of 60 day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallop Chlamys farreri were studied in laboratory from Oct. 17 to Dec. 15,1997. Two groups (control and starvation with 200 individuals each) were cultured in two 2 m 3 tanks, with 31 to 32 salinity water at 17℃. Starvation effects were measured after 10, 20, 40 and 60 days. There was no mass mortality of scallops of the two tanks and survival rates of the control and starvation groups were 93.5% and 92.0%, respectively. Starvation had strong effect on the meat condition of the scallops, especially after 10 days; when relative lipid percentage dropped sharply while relative protein percentage increased. The impact of starvation on the oxygen consumption rate (OCR) and the ammonia N excretion rate (AER) was obvious. The OCR increased rapidly after 10 days but decreased after 20 days. The AER increased after 10 days and 20 days, but decreased obviously from 20 to 40 days. The O:N ratios varied to different degrees, and minimized after 20 days. The low O:N ratios implied that the protein was the main material for the metabolism of C. farreri.展开更多
The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish （Procambarus clarkii）, and the results showed the effect was ...The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish （Procambarus clarkii）, and the results showed the effect was obvious. In a 70-day starvation experiment, mean body weight, exuvial rate, abdominal muscle ratio and hepatosomatic index decreased significantly. The percentage of protein, fat, ash and moisture were also significantly affected. The protein content decreased sharply at Day 30 onward and the percentage of fat decreased rapidly from Day 50 and on. The percentages of ash and moisture started to increase significantly at Day 40 and 30 respectively. After the starvation experiment, the hepatopancreatic total and neutral lipid content decreased slightly from 23.90% to 20.39% and 73.75% to 70.35%, while the hepatopancreatic polar lipid content increased from 23.81% to 27.32%. On the other hand, all the muscular total, neutral and polar lipid contents, and the muscular fatty acid compositions did not change significantly except for the hepatopancreatic fatty acid composition. The relative percentages of 14：0, 16：0, 16：1n-7 and 18：1n-9 were decreased by 55.17%, 11.11%, 8.5% and 6.70% from the initial values, and the relative percentages of 18：2n-6, 18：3n-3, 20：4n-6, 20：5n-3 and 22：6n-3 increased obviously from 5.2%, 3.9%,4, 2.4%, 10.6%, and 13.7% to 7.1%, 5.0%, 2.8%, 11.5%, and 14.4% respectively. Preference of utilization of fatty acids from hepatopancreas during starvation was as follows： 14：0〉16：0〉16：1n-7〉18：1n-9, and the conservation of highly unsaturated fatty acids was in the order of： 18：2n-6 〉18：3n-3〉20：4n-6〉20：5n-3〉22：6n-3.展开更多
Feeding and sleep are highly conserved,interconnected behaviors essential for survival.Starvation has been shown to potently suppress sleep across species;however,whether satiety promotes sleep is still unclear.Here w...Feeding and sleep are highly conserved,interconnected behaviors essential for survival.Starvation has been shown to potently suppress sleep across species;however,whether satiety promotes sleep is still unclear.Here we use the fruit fly,Drosophila melanogaster,as a model organism to address the interaction between feeding and sleep.We first monitored the sleep of flies that had been starved for 24 h and found that sleep amount increased in the first 4 h after flies were given food.Increased sleep after starvation was due to an increase in sleep bout number and average sleep bout length.Mutants of translin or adipokinetic hormone,which fail to suppress sleep during starvation,still exhibited a sleep increase after starvation,suggesting that sleep increase after starvation is not a consequence of sleep loss during starvation.We also found that feeding activity and food consumption were higher in the first 10-30 min after starvation.Restricting food consumption in starved flies to 30 min was sufficient to increase sleep for 1 h.Although flies ingested a comparable amount of food at differing sucrose concentrations,sleep increase after starvation on a lower sucrose concentration was undetectable.Taken together,our results suggest that increased food intake after starvation enhances sleep and reveals a novel relationship between feeding and sleep.展开更多
Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this rev...Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this review,we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adaptive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes,evaluating the nutrition condition and growth of larval fish,protecting fish resource and breeding fish larvae.展开更多
Side-effects associated with the cancer chemotherapy limit the scope of chemotherapeutic drugs and no data was available about these side effects in Pakistan. Moreover starvation based differential chemotherapy has be...Side-effects associated with the cancer chemotherapy limit the scope of chemotherapeutic drugs and no data was available about these side effects in Pakistan. Moreover starvation based differential chemotherapy has been proved to greatly reduce the side effects of chemotherapy depending on starvation time. The current study was conducted to survey the common side effects of the chemotherapeutic drugs and the role of starvation to reduce them. The study included total 100 subjects with multiple carcinomas. A comprehensive questionnaire about starvation inquiry, chemotherapy side effects and their basic information was filled by interviewers as told by patients. There were 48% patients with breast cancer and 11% with uterine cancer. Out of these patients 30%, 28%, 9% and 9% patients were agreed to starve for 12, 24, 36 and 48 hours respectively. The survey regarding the side effects of chemotherapy showed that 43% patients were suffering from headache, fatigue 90%, weakness 95%, hair loss 76%, nausea 77%, vomiting 75%, diarrhea 31%, abdominal cramps 40%, mouth sores 47%, dry mouth 74%, memory impairment 14%?and numbness 49%. Breast cancer is the most common cancer in Pakistan. Only 18% of the total patients were agreed to starve for more than one day. Chemotherapy-associated side effects vary greatly and it does not depend upon cancer type. But these side effects depend on multiple factors such as the type and dose of chemotherapeutic drug, patient’s health status and stage of cancer.展开更多
In the industrial operation of biotrickling filters for hydrogen sulfide(H2S) removal,shock loads or starvation was common due to process variations or equipment malfunctions.In this study,effects of starvation and sh...In the industrial operation of biotrickling filters for hydrogen sulfide(H2S) removal,shock loads or starvation was common due to process variations or equipment malfunctions.In this study,effects of starvation and shock loads on the performance of biotrickling filters for H2S removal were investigated.Four experiments were conducted to evaluate the changes of biomass and viable bacteria numbers in the biotrickling filters during a 24-d starvation.Compared to biomass,viable bacteria numbers decreased significantly during the starvation,especially when airflow was maintained in the absence of spray liquid.During the subsequent re-acclimation,all the bioreactors could resume high removal efficiencies within 4 d regardless of the previous starvation conditions.The results show that the re-acclimation time,in the case of biotrickling filters for H2S removal,is mainly controlled by viable H2S oxidizing bacteria numbers.On the other hand,the biotrickling filters can protect against shock loads in inlet fluctuating H2S concentration after resuming normal operation.When the biotrickling filters were supplied with H2S at an input of lower than 1700 mg/m3,their removal efficiencies were nearly 98% regardless of previous H2S input.展开更多
At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return （PNR） was reached on the 6th day after hatching. On the 4t...At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return （PNR） was reached on the 6th day after hatching. On the 4th day after hatching, the pectoral angle appeared in both fed and unfed anchovy larvae although it was more evident and sharper in the starved and the PNR stage larvae than in the fed ones. According to observations of larvae collected in the sea, the pectoral angles were evident not only in the larvae of 3.62 - 7.44 mm in standard length, but also in the larvae of 2.70 mm in standard length with remnants of yolk. The pectoral angles became diffuse when the larvae reached 7.84 mm and vanished at 9.86 mm. The pectoral angle cannot be used as a criterion to distinguish healthy from starving larvae.展开更多
GmPHR1 from soybean （Glycine max） was isolated and characterized. This novel homolog of the AtPHR1 transcription factor confers tolerance to inorganic phosphate （Pi）-starvation. The gene is 2 751 bp long, with an ...GmPHR1 from soybean （Glycine max） was isolated and characterized. This novel homolog of the AtPHR1 transcription factor confers tolerance to inorganic phosphate （Pi）-starvation. The gene is 2 751 bp long, with an 819-bp open reading frame and ifve introns. Analysis of transcription activity in yeast revealed that the full-length GmPHR1 and its C-terminal activate the reporter genes for His, Ade and Ura, suggesting that the C-terminal peptide functions as a transcriptional activator. Quantitative real-time PCR indicated that patterns of GmPHR1 expression differed. For example, under low-Pi stress, this gene was quickly induced in the tolerant JD11 after 0.5 h, with expression then decreasing slowly before peaking at 12-24 h. By contrast, induction in the sensitive Niumaohuang （NMH） was slow, peaking at 6 h before decreasing quickly at 9 h. GmPHR1 showed sub-cellular localization in the nuclei of onion epidermal cells and Arabidopsis roots. Growth parameters in wild-type （WT） Arabidopsis plants as well as in overexpression （OE） transgenic lines were examined. Under low-Pi conditions, values for shoot, root and whole-plant dry weights, root to shoot ratios, and lengths of primary roots were signiifcantly greater in OE lines than in the WT. These data demonstrate that GmPHR1 has an important role in conferring tolerance to phosphate starvation.展开更多
Chemodynamic therapy(CDT)as an emerging modality in cancer treatment,its implementation remains a daunting challenge by the lack of smart Fenton catalyst under acidic tumor microenvironments.Herein,we have successfull...Chemodynamic therapy(CDT)as an emerging modality in cancer treatment,its implementation remains a daunting challenge by the lack of smart Fenton catalyst under acidic tumor microenvironments.Herein,we have successfully constructed a Fe_(3)O_(4)@MIL-100 heterojunction by growing Fe-based metal-organic framework(MIL-100)onto the surface of Fe_(3)O_(4) nanoparticles.The as-made heterojunction after encapsu-lating glucose oxidase(termed FMG)is demonstrated as a pH-responsive intelligent Fenton nanosystem with the synergistic effect of starvation therapy(ST).Density functional theory(DFT)calculations reveal that such heterojunction could greatly reduce the energy barrier of the Fenton reaction,which better ex-plains the mechanism of Fenton performance improvement.Moreover,the encapsulated glucose oxidase has successfully activated the ST process,in which its generated H_(2)O_(2) and gluconic acid further improve the CDT efficiency.More O_(2) from the enhanced CDT in turn promotes the enzymatic reaction of glucose oxidase.The Fenton/cascade enzymatic reaction operates in a self-feedback manner as proposed.In vitro and in vivo experiments demonstrate that such intelligent Fenton nanoreactors provide a powerful anti-cancer mechanism for effective tumor ablation with enough safety.This work provides insights into the developments of MOF-based heterojunctions as powerful anticancer treatment nanoreactors.展开更多
Nitrogen is an essential macronutrient for all living organisms and is critical for crop productivity and quality.In higher plants,inorganic nitrogen is absorbed through roots and then assimilated into amino acids by ...Nitrogen is an essential macronutrient for all living organisms and is critical for crop productivity and quality.In higher plants,inorganic nitrogen is absorbed through roots and then assimilated into amino acids by the highly conserved glutamine synthetase/glutamine:2-oxoglutarate aminotransferase(GS/GOGAT)cycle.How nitrogen metabolism and nitrogen starvation responses of plants are regulated remains largely unknown.Previous studies revealed that mutations in the rice ABNORMAL CYTOKININ RESPONSE1(ABC1)gene encoding Fd-GOGAT cause a typical nitrogen deficiency syndrome.Here,we show that ARE2(for ABC1 REPRESSOR2)is a key regulator of nitrogen starvation responses in rice.The are2 mutations partially rescue the nitrogen-deficient phenotype of abc1 and the are2 mutants show enhanced tolerance to nitrogen deficiency,suggesting that ARE2 genetically interacts with ABC1/Fd-GOGAT.ARE2 encodes a chloroplast-localized Rel A/Spo T homolog protein that catalyzes the hydrolysis of guanosine pentaphosphate or tetraphosphate(p)pp Gpp,an alarmone regulating the stringent response in bacteria under nutritional stress conditions.The are2 mutants accumulate excessive amounts of(p)pp Gpp,which correlate with lower levels of photosynthetic proteins and higher amino acid levels.Collectively,these observations suggest that the alarmone(p)pp Gpp mediates nitrogen stress responses and may constitute a highly conserved mechanism from bacteria to plants.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFA1207600)the National Natural Science Foundation of China(Nos.62375289,62175262)+2 种基金the Science and Technology Innovation Program of Hunan Province(No.2022RC1201)the Scientific Research Fund of Hunan Provincial Education Department(No.22B0081)Postdoctoral Funding Project of Jiangsu Province(No.2019Z156)。
文摘Designing and synthesizing nanomedicines with multi-modal tumor therapeutic capabilities is the key to cancer treatment.Herein,we prepared MICG nanoparticles(NPs)by assembling glucose oxidase(GOx)and indocyanine green(ICG)with manganese carbonate(MnCO_(3))NPs for starvation therapy cascaded chemodynamic therapy,enhanced phototherapy and immune activation.In MICG NPs,the GOx consumes intratumoral glucose resulting in starvation therapy,and simultaneously produces H_(2)O_(2)and decreases p H in tumor.The intensified acidic tumor environment promotes the decomposition of MnCO_(3)NPs to release Mn^(2+).The Mn^(2+)further catalyzes H_(2)O_(2)to generate hydroxyl radical for chemodynamic therapy.While ICG can generate singlet oxygen(^(1)O_(2))and heat to kill cancer cells through phototherapy mechanism.The hydroxyl radical and ^(1)O_(2) will further accelerate the oxidative stress,intensify immunogenic cell death,induce dendritic cell maturation,and thus activate systemic immunity.This work provides a new therapeutic platform for combining therapy of tumor.
基金supported by the National Natural Science Foundation of China(No.52270018).
文摘The organic matter inmunicipal wastewater can be recovered by anaerobic biological treatment,making further resource utilization of municipal wastewater,which meets the requirements of sustainable development.An upflow anaerobic biofilter(UAF)treating municipal wastewater was established.The performances of stable operation and recovery operation of UAF after long-term starvation(234 days)and the changes of microbial community structure were researched.By gradually reducing HRT from 10 h to 4 h,the UAF achieved the treatment performance of pre-starvation after only 50 days recovery operation,in which total COD and soluble COD removal efficiencies reached 66%and 69%,respectively,and the CH_(4) production rate was 0.21 L CH_(4)/g CODremoval.The recovery performance of UAF after long term starvation showed that the recovery sequence of three main anaerobic processes was hydrolytic acidification,hydrogen-acetate production and methanogenesis.High-throughput sequencing results indicated that dominant bacteria associated with hydrolytic acidification process changed from Moduliflexaceae and Trichococcus in stable operation stage to Trichococcus and Romboutsia in recovery stage.Besides,the dominant archaea changed from Methanosaeta(hydrotrophic methanogens)to Methanobacterium(acetotrophic methanogens),showing Methanobacterium was more resistant to starvation environment.Therefore,by using UAF for biological treatment of organic matter,even after a long period of starvation,the system would not be completely destroyed.Once it resumed operation,the treatment performance could be restored in a short period of time.
基金Project(2023A1515012146)supported by the Guangdong Basic and Applied Research Foundation,ChinaProjects(52271083,51901253,52371059,52071091)supported by the National Natural Science Foundation of ChinaProject(2023HA-TYUTKFYF029)supported by the Open Research Fund from the Hai’an&Taiyuan University of Technology Advanced Manufacturing and Intelligent Equipment Industrial Research Institute,China。
文摘Copper-nickel alloys can suffer severe localized corrosion in marine environments containing sulfate-reducing bacteria(SRB),but the effect of SRB on the under-deposit corrosion of copper-nickel alloys is unknown.In this work,the corrosion behavior of B10 copper-nickel alloy beneath a deposit caused by SRB with carbon source starvation in artificial seawater was studied based on electrochemical measurements and surface analysis.Results demonstrate that SRB with an organic carbon starvation can survive in artificial water but most SRB cells have died.The survived SRB cells can attach to the bare and deposit-covered B10 copper-nickel alloy,leading to the corrosion acceleration.Due to the limitation of organic carbon source,the pitting corrosion of B10 copper-nickel alloy caused by SRB is not serious.However,serious pitting corrosion of the deposit-covered B10 copper-nickel alloy can be found both in abiotic and biotic conditions,and the pitting corrosion and uniform corrosion are further accelerated by SRB.There is a galvanic effect between the bare and deposit-covered specimens in the presence of SRB in the early stage but the galvanic effect after 5 d of testing can be neglected due to the low OCP difference values.
文摘Starvation in Karamoja remains one of human’s greatest infamies. Not blinking at this fact has resulted in solicitation for more permanent solutions. As part of this, the current study ventured into identifying individual and household factors that add stone to starvation among FHHs compared to MHHs. An Oaxaca Blinder Decomposition extended on Logistic regression was applied. The study found that income, education, age, land access and livestock ownership were factors behind the difference in starvation levels between male and female-headed households. The study suggests policies that promote gender equality, challenge traditional gender roles, and empower women economically and socially to significantly address barriers and create a supportive environment crucial for long-term solutions.
文摘Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subsequently conducted under greenhouse conditions to further characterize APase activity and its isoform expression induced by P starvation. Results from the field experiment showed that there was a great genotypic variation for leaf APase activity among the tested soybean genotypes from different origins, and APase activity in many of the tested genotypes (about 60%) was generally increased in the treatment without P fertilizer addition. Results from the nutrient solution culture experiment showed that APase activity in all the eight tested genotypes was generally enhanced by P starvation. Six isoforms of APases were detected in isoelectric focusing gels with samples from both young and old leaves. The activity of all the six isoforms was increased by P starvation, but no new APase isoform was induced. Our results suggest that leaf APase activity could serve as an enzymatic indicator of P starvation for soybean; the increase in leaf APase activity under low P stress was mainly caused by the increase in the activity of existing isoforms but not by the induction of new isoforms.
文摘Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate the molecular background of the adaptive mechanisms, the suppression subtractive hybridization (SSH) method was used to construct a rice phosphorus-starvation ( Pi-starvation) induced cDNA library. Through screening of the cDNA library and sequencing of the enriched cDNAs, 18 known genes and 47 novel genes were identified. The known genes are involved in different metabolic processes, including phosphate uptake and transport, signal transduction, protein synthesis and degradation, carbon metabolism and stress response. Northern analysis was performed to detect the expression patterns of some known genes and novel genes under different phosphorus levels. Different expression patterns of the selected genes were identified, which suggests that genes involved in different pathways may have different responses to Pi-starvation.
基金Supported by Scientific and Technical Research Funds from Chinese PLA during the Eleventh Five-Year Plan Period,No. 2008G093National Natural Science Foundation of China,No. 30900715National Science and Technology Ministry,No. 2009BAI85B03
文摘AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.
基金supported by the National Natural Science Foundation of China(Grant No.31701329)the Project Funded by China Postdoctoral Science Foundation(Grant No.2015M580560)。
文摘To clarify the complex regulatory relationship between changes in sugar content and leaf senescence during the grain-filling stage of rice,genotype-dependent differences in sugar content and the temporal transcriptional patterns of genes involved in sugar signaling pathways were determined in mutant rice exhibiting early leaf senescence and its wild type Zhefu 142.The effects of exogenous glucose or sucrose on the senescence of detached leaves under dark conditions were also investigated.Chlorophyll,soluble sugar,sucrose and fructose contents decreased,whereas electrolytic leakage and malondialdehyde levels increased in mutant leaves at the grain-filling stage.These results suggested that sugar starvation is positively correlated with the early leaf senescence of mutant plants.Detached leaf segments incubated in exogenous sugar solutions under dark conditions exhibited delayed senescence.The high expression of Hxk1 in leaves of mutant plants at the initial grain-filling stage suggested that Hxk1 is involved in the hexose-sensing process at the early stage of leaf senescence.The low expression levels of Hxk2 and Frk1 in the senescing leaves of mutant rice during the grain-filling stage are indicative of weakened hexose phosphorylation.In addition,the high expression levels of Su Sy1,Su Sy2 and Su Sy4 in leaves of mutant plants at the initial grain-filling stage are accompanied by the high transcript levels of SUT1,which favor sucrose translocation and remobilization from the early senescing leaves of mutant rice.The relatively reduced transcript levels of ch FBP,cy FBP,SPS1,SPS2 and SPS6 indicated that during the grain-filling stage,sucrose biosynthesis is weakened in the senescing leaves of mutant rice.
基金supported by the National Natural Science Foundation of China (31571664 and 31671686)the Key Research and Development Project of Hebei, China (17962901D)
文摘Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator gene in Triticum aestivum, in mediating the N starvation adaptation in plants. Ta ARR1 harbors two conserved domains specified by plant ARR family members;subcellular localization analysis indicated its target onto nucleus after endoplasmic reticulum assortment. Ta ARR1 displayed modified expression upon the N starvation stressor, showing upregulated expression in roots and leaves over a 27-h N starvation treatment and whose induced transcripts were gradually recovered along with progression of the N recovery treatment. The tobacco lines overexpressing Ta ARR1 displayed improved low-N stress tolerance, displaying enlarged phenotype, increased biomass and N accumulation, and enhanced glutamine synthetase(GS) activities compared with wild type(WT) following the N starvation treatment. Expression analysis on genes encoding the nitrate transporter(NRT) and GS proteins in Nicotiana tabacum revealed that Nt NRT2.2 and Nt GS3 are upregulated in expression in the N-deprived transgenic lines, whose expression patterns were contrasted to other above family genes that were unaltered on transcripts between the transgenic lines and WT. Transgene analysis validated the function of Nt NRT2.2 and Nt GS3 in regulating N accumulation, GS activity, growth traits, and N use efficiency in plants. These results suggested the internal connection between the Ta ARR1-mediated N starvation tolerance and the modified transcription of distinct N acquisitionand assimilation-associated genes. Our investigation together indicates that Ta ARR1 is essential in plant N starvation adaptation due to the gene function in transcriptionally regulating distinct NRT and GS genes that affect plant N uptake and assimilation under the N starvation condition.
文摘The effects of 60 day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallop Chlamys farreri were studied in laboratory from Oct. 17 to Dec. 15,1997. Two groups (control and starvation with 200 individuals each) were cultured in two 2 m 3 tanks, with 31 to 32 salinity water at 17℃. Starvation effects were measured after 10, 20, 40 and 60 days. There was no mass mortality of scallops of the two tanks and survival rates of the control and starvation groups were 93.5% and 92.0%, respectively. Starvation had strong effect on the meat condition of the scallops, especially after 10 days; when relative lipid percentage dropped sharply while relative protein percentage increased. The impact of starvation on the oxygen consumption rate (OCR) and the ammonia N excretion rate (AER) was obvious. The OCR increased rapidly after 10 days but decreased after 20 days. The AER increased after 10 days and 20 days, but decreased obviously from 20 to 40 days. The O:N ratios varied to different degrees, and minimized after 20 days. The low O:N ratios implied that the protein was the main material for the metabolism of C. farreri.
基金Supported by the Scientific Fund of Chinese Postdoctor (No. 2002032195).
文摘The effect of starvation on physiological and biochemical indicators of body, muscle and hepatopancreas were investigated for juvenile red swamp crawfish （Procambarus clarkii）, and the results showed the effect was obvious. In a 70-day starvation experiment, mean body weight, exuvial rate, abdominal muscle ratio and hepatosomatic index decreased significantly. The percentage of protein, fat, ash and moisture were also significantly affected. The protein content decreased sharply at Day 30 onward and the percentage of fat decreased rapidly from Day 50 and on. The percentages of ash and moisture started to increase significantly at Day 40 and 30 respectively. After the starvation experiment, the hepatopancreatic total and neutral lipid content decreased slightly from 23.90% to 20.39% and 73.75% to 70.35%, while the hepatopancreatic polar lipid content increased from 23.81% to 27.32%. On the other hand, all the muscular total, neutral and polar lipid contents, and the muscular fatty acid compositions did not change significantly except for the hepatopancreatic fatty acid composition. The relative percentages of 14：0, 16：0, 16：1n-7 and 18：1n-9 were decreased by 55.17%, 11.11%, 8.5% and 6.70% from the initial values, and the relative percentages of 18：2n-6, 18：3n-3, 20：4n-6, 20：5n-3 and 22：6n-3 increased obviously from 5.2%, 3.9%,4, 2.4%, 10.6%, and 13.7% to 7.1%, 5.0%, 2.8%, 11.5%, and 14.4% respectively. Preference of utilization of fatty acids from hepatopancreas during starvation was as follows： 14：0〉16：0〉16：1n-7〉18：1n-9, and the conservation of highly unsaturated fatty acids was in the order of： 18：2n-6 〉18：3n-3〉20：4n-6〉20：5n-3〉22：6n-3.
基金supported by the National Institutes of Health COBRE Grant P20 GM103650
文摘Feeding and sleep are highly conserved,interconnected behaviors essential for survival.Starvation has been shown to potently suppress sleep across species;however,whether satiety promotes sleep is still unclear.Here we use the fruit fly,Drosophila melanogaster,as a model organism to address the interaction between feeding and sleep.We first monitored the sleep of flies that had been starved for 24 h and found that sleep amount increased in the first 4 h after flies were given food.Increased sleep after starvation was due to an increase in sleep bout number and average sleep bout length.Mutants of translin or adipokinetic hormone,which fail to suppress sleep during starvation,still exhibited a sleep increase after starvation,suggesting that sleep increase after starvation is not a consequence of sleep loss during starvation.We also found that feeding activity and food consumption were higher in the first 10-30 min after starvation.Restricting food consumption in starved flies to 30 min was sufficient to increase sleep for 1 h.Although flies ingested a comparable amount of food at differing sucrose concentrations,sleep increase after starvation on a lower sucrose concentration was undetectable.Taken together,our results suggest that increased food intake after starvation enhances sleep and reveals a novel relationship between feeding and sleep.
文摘Starvation has important effects on early development of fish. It determines the survival and growth of fish larvae,and plays an important role in the dynamics of fish population and fisheries recruitment. In this review,we discuss the current studies about the effects of starvation on growth and development of fish larval stage. The goals of this review are to understand some adaptive mechanisms and ecological countermeasures of starved fish larvae and to provide the scientific guideline for exploring early life history processes,evaluating the nutrition condition and growth of larval fish,protecting fish resource and breeding fish larvae.
文摘Side-effects associated with the cancer chemotherapy limit the scope of chemotherapeutic drugs and no data was available about these side effects in Pakistan. Moreover starvation based differential chemotherapy has been proved to greatly reduce the side effects of chemotherapy depending on starvation time. The current study was conducted to survey the common side effects of the chemotherapeutic drugs and the role of starvation to reduce them. The study included total 100 subjects with multiple carcinomas. A comprehensive questionnaire about starvation inquiry, chemotherapy side effects and their basic information was filled by interviewers as told by patients. There were 48% patients with breast cancer and 11% with uterine cancer. Out of these patients 30%, 28%, 9% and 9% patients were agreed to starve for 12, 24, 36 and 48 hours respectively. The survey regarding the side effects of chemotherapy showed that 43% patients were suffering from headache, fatigue 90%, weakness 95%, hair loss 76%, nausea 77%, vomiting 75%, diarrhea 31%, abdominal cramps 40%, mouth sores 47%, dry mouth 74%, memory impairment 14%?and numbness 49%. Breast cancer is the most common cancer in Pakistan. Only 18% of the total patients were agreed to starve for more than one day. Chemotherapy-associated side effects vary greatly and it does not depend upon cancer type. But these side effects depend on multiple factors such as the type and dose of chemotherapeutic drug, patient’s health status and stage of cancer.
基金supported by the Foundation for Society Development of Jilin Province (No.20080412-1)the Education Research Foundation for Science and Technology Development of Jilin Provincethe Foundation for Doctor Research in Northeast Dianli University of Jilin Province (No.BSJXM-200710),China
文摘In the industrial operation of biotrickling filters for hydrogen sulfide(H2S) removal,shock loads or starvation was common due to process variations or equipment malfunctions.In this study,effects of starvation and shock loads on the performance of biotrickling filters for H2S removal were investigated.Four experiments were conducted to evaluate the changes of biomass and viable bacteria numbers in the biotrickling filters during a 24-d starvation.Compared to biomass,viable bacteria numbers decreased significantly during the starvation,especially when airflow was maintained in the absence of spray liquid.During the subsequent re-acclimation,all the bioreactors could resume high removal efficiencies within 4 d regardless of the previous starvation conditions.The results show that the re-acclimation time,in the case of biotrickling filters for H2S removal,is mainly controlled by viable H2S oxidizing bacteria numbers.On the other hand,the biotrickling filters can protect against shock loads in inlet fluctuating H2S concentration after resuming normal operation.When the biotrickling filters were supplied with H2S at an input of lower than 1700 mg/m3,their removal efficiencies were nearly 98% regardless of previous H2S input.
文摘At a temperature of 23.0 - 24.8℃, the mixed feeding of Japanese anchovy larvae was initiated 24 h before the yolk-sac was exhausted. The point of no return （PNR） was reached on the 6th day after hatching. On the 4th day after hatching, the pectoral angle appeared in both fed and unfed anchovy larvae although it was more evident and sharper in the starved and the PNR stage larvae than in the fed ones. According to observations of larvae collected in the sea, the pectoral angles were evident not only in the larvae of 3.62 - 7.44 mm in standard length, but also in the larvae of 2.70 mm in standard length with remnants of yolk. The pectoral angles became diffuse when the larvae reached 7.84 mm and vanished at 9.86 mm. The pectoral angle cannot be used as a criterion to distinguish healthy from starving larvae.
基金supported by the National Natural Science Foundation of China (31071441, 31401405)the National Transgenic Major Project of China (2014ZX0800404B)
文摘GmPHR1 from soybean （Glycine max） was isolated and characterized. This novel homolog of the AtPHR1 transcription factor confers tolerance to inorganic phosphate （Pi）-starvation. The gene is 2 751 bp long, with an 819-bp open reading frame and ifve introns. Analysis of transcription activity in yeast revealed that the full-length GmPHR1 and its C-terminal activate the reporter genes for His, Ade and Ura, suggesting that the C-terminal peptide functions as a transcriptional activator. Quantitative real-time PCR indicated that patterns of GmPHR1 expression differed. For example, under low-Pi stress, this gene was quickly induced in the tolerant JD11 after 0.5 h, with expression then decreasing slowly before peaking at 12-24 h. By contrast, induction in the sensitive Niumaohuang （NMH） was slow, peaking at 6 h before decreasing quickly at 9 h. GmPHR1 showed sub-cellular localization in the nuclei of onion epidermal cells and Arabidopsis roots. Growth parameters in wild-type （WT） Arabidopsis plants as well as in overexpression （OE） transgenic lines were examined. Under low-Pi conditions, values for shoot, root and whole-plant dry weights, root to shoot ratios, and lengths of primary roots were signiifcantly greater in OE lines than in the WT. These data demonstrate that GmPHR1 has an important role in conferring tolerance to phosphate starvation.
基金supported by the Hainan Provincial Key Research and Development Program(No.ZDYF2021SHFZ246)the National Natural Science Foundation of China(Nos.52003069 and 51872263).
文摘Chemodynamic therapy(CDT)as an emerging modality in cancer treatment,its implementation remains a daunting challenge by the lack of smart Fenton catalyst under acidic tumor microenvironments.Herein,we have successfully constructed a Fe_(3)O_(4)@MIL-100 heterojunction by growing Fe-based metal-organic framework(MIL-100)onto the surface of Fe_(3)O_(4) nanoparticles.The as-made heterojunction after encapsu-lating glucose oxidase(termed FMG)is demonstrated as a pH-responsive intelligent Fenton nanosystem with the synergistic effect of starvation therapy(ST).Density functional theory(DFT)calculations reveal that such heterojunction could greatly reduce the energy barrier of the Fenton reaction,which better ex-plains the mechanism of Fenton performance improvement.Moreover,the encapsulated glucose oxidase has successfully activated the ST process,in which its generated H_(2)O_(2) and gluconic acid further improve the CDT efficiency.More O_(2) from the enhanced CDT in turn promotes the enzymatic reaction of glucose oxidase.The Fenton/cascade enzymatic reaction operates in a self-feedback manner as proposed.In vitro and in vivo experiments demonstrate that such intelligent Fenton nanoreactors provide a powerful anti-cancer mechanism for effective tumor ablation with enough safety.This work provides insights into the developments of MOF-based heterojunctions as powerful anticancer treatment nanoreactors.
基金supported by grants from the Ministry of Agriculture and Rural Affairs of China(2016ZX08009003-0022016ZX08009003-005 and 2016ZX08009003-004)+2 种基金Chinese Academy of Sciences(XDA08010401-2)the Ministry of Science and Technology of the People’s Republic of China(2016YFD0100706)the State Key Laboratory of Plant Genomics。
文摘Nitrogen is an essential macronutrient for all living organisms and is critical for crop productivity and quality.In higher plants,inorganic nitrogen is absorbed through roots and then assimilated into amino acids by the highly conserved glutamine synthetase/glutamine:2-oxoglutarate aminotransferase(GS/GOGAT)cycle.How nitrogen metabolism and nitrogen starvation responses of plants are regulated remains largely unknown.Previous studies revealed that mutations in the rice ABNORMAL CYTOKININ RESPONSE1(ABC1)gene encoding Fd-GOGAT cause a typical nitrogen deficiency syndrome.Here,we show that ARE2(for ABC1 REPRESSOR2)is a key regulator of nitrogen starvation responses in rice.The are2 mutations partially rescue the nitrogen-deficient phenotype of abc1 and the are2 mutants show enhanced tolerance to nitrogen deficiency,suggesting that ARE2 genetically interacts with ABC1/Fd-GOGAT.ARE2 encodes a chloroplast-localized Rel A/Spo T homolog protein that catalyzes the hydrolysis of guanosine pentaphosphate or tetraphosphate(p)pp Gpp,an alarmone regulating the stringent response in bacteria under nutritional stress conditions.The are2 mutants accumulate excessive amounts of(p)pp Gpp,which correlate with lower levels of photosynthetic proteins and higher amino acid levels.Collectively,these observations suggest that the alarmone(p)pp Gpp mediates nitrogen stress responses and may constitute a highly conserved mechanism from bacteria to plants.
