Variation in metabolite profiles of Haematococcus pluvialis(a type of unicellular green algal)under light stress is a key issue of study at the present.To investigate the effect of light intensity on accumulation of a...Variation in metabolite profiles of Haematococcus pluvialis(a type of unicellular green algal)under light stress is a key issue of study at the present.To investigate the effect of light intensity on accumulation of astaxanthin in H.pluvialis,a 26-day batch culture experiment of H.pluvialis under the light intensity levels at 73,127,182,236,and 291μmol/(m^(2)·s)was conducted.Therefore,the optimal light intensity and the corresponding metabolic pathways of accumulation in H.pluvialis were determined.Results show that 236μmol/(m^(2)·s)was the optimum light intensity to induce astaxanthin accumulation,at which a maximum content of 9.01 mg/L was achieved on Day 24.A total of 132 metabolites were identified and quantified,of which 38 differential metabolites were highlighted and classified,including 3 fatty acids or intermediates,5 amino acids or derivatives,5 carbohydrates or intermediates,16nucleoside derivatives,and 9 other metabolites using LC-MS/MS technique.Subsequently,16 statistically significant differential metabolic pathways were enriched and annotated based on Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis between the control and the 236μmol/(m^(2)·s)treatment group(P<0.05).In addition,the bioprocesses included cellular basal metabolism and signaling systems,such as carbohydrate metabolism,amino acid metabolism,glycerol and derivatives metabolism,nucleotide and derivative metabolism,and inositol phosphate metabolism were activated and regulated under strong light stress conditions.Moreover,4 hub metabolites containing D-glucose-6-phosphate,L-tyrosine,glycerol-3-phosphate,and L-glutamine were identified,based on which the associated metabolic network was constructed.The study provided a metabolomic view of astaxanthin accumulation in H.pluvialis under strong light stress.展开更多
Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoin...Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoinhibition) of rice ( Oryza sativa L.) was comparatively investigated. In both cultivars of rice, the excitation energy distribution between two photosystems was altered and the excitation energy transfer from light harvesting chlorophyll protein complexes to PSⅡ was inhibited by high light stress. These decreases were more pronounced in indica rice cultivar as compared to japonica one. The analysis of mild SDS_PAGE showed that in indica rice, high light stress almost disaggregated the trimer of light harvesting chlorophyll protein complexes of PSⅡ (LHC Ⅱ 1). The stress reduced the contents of internal antennae chlorophyll protein complexes of PSⅡ (CPa), light harvesting chlorophyll protein of PSⅠ (CPⅠa) and Chl a protein complex of PSⅠ reaction center (CPⅠ) as well as dimer of LHCⅡ (LHCⅡ 2) in indica rice. In japonica subspecies, however, high light stress depressed the contents of LHCⅡ 1, CPa and CPⅠa, but slightly impacted on CPⅠ content. Moreover, the increase in the contents of monomer of LHCⅡ by high light stress was found in both subspecies. In consistent with above results, analysis of polypeptide indicated that the amounts of 27 kD and 25 kD polypeptide of LHCⅡ in particular, as well as that of 21 kD polypeptide of CPⅠa were reduced by high light stress in both subspecies. It was found that, comparing with japonica rice, the stress pronouncedly diminished 43 kD and 47 kD proteins of CPa and 23 kD extrisic protein in indica rice.展开更多
The oxygen evolution, thermal dissipation, and photochemical energy storage of three hybrid poplar clones, namely the triploid clone B342, the diploid clone B11 [(Populus alba×P. glandulosa)×(P.tomentosa...The oxygen evolution, thermal dissipation, and photochemical energy storage of three hybrid poplar clones, namely the triploid clone B342, the diploid clone B11 [(Populus alba×P. glandulosa)×(P.tomentosa×P.bolleana)], and the triploid clone B346 [(P.tomentosa×P. bolleana)×(P. alba×P.glandulosa)], under light stress were studied using photoacoustics. The oxygen evolution signal and photochemical energy storage varied negatively with the pretreatment_PFD (photon flux density), whereas the thermal signal varied positively with the pretreatment_PFD. Photochemical energy storage was reallocated to PSⅡ more than to PSⅠ, while the photochemical energy storage in PSⅠ was more stable than that in PSⅡ when subjected to light stress. The inhibitors streptomycin (SM), dithiothreitol (DTT) and sodium fluoride (NaF) could all affect the oxygen evolution signal. Clones B11 and B342 were more resistant to light stress than clone B346.展开更多
Large yellow croaker(Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an oppor...Large yellow croaker(Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an opportunity of investigating the molecular responding mechanism of teleost in light stress. The gene expression profile of fish under light stress is rarely documented. In this research, the transcriptome profiles of the abdominal skin of L. crocea exposed to light or dark for 0 h, 0.5 h and 2 h were produced by next-generation sequencing(NGS). The cluster results demonstrated that stress period, rather than light intensity(e.g., light or dark), is the major influencing factor. Differently expressed genes(DEGs) were identified between 0 h and 0.5 h groups, between 0 h and 2 h groups, between 0.5 h light and 0.5 h dark, and between 2 h light and 2 h dark, respectively. The gene ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) annotation revealed that the genes relating to immunity, energy metabolism, and cytoskeletal protein binding were significantly enriched. The detailed analysis of transcriptome profiles also revealed regular gene expression trends, indicating that the elaborate gene regulation networks underlined the molecular responses of the fish to light stress. This transcriptome analysis suggested that systematic and complicated regulatory cascades were functionally activated in response to external stress, and coloration change caused by light stress was mainly attributed to the change in the density of chromatophores for L. crocea. This study also provided valuable information for skin coloration or light stress research on other marine fish species.展开更多
Plants require solar energy to grow through oxygenic photosynthesis;however,when light intensity exceeds the optimal range for photosynthesis,it causes abiotic stress and physiological damage in plants.In response to ...Plants require solar energy to grow through oxygenic photosynthesis;however,when light intensity exceeds the optimal range for photosynthesis,it causes abiotic stress and physiological damage in plants.In response to high light stress,plants initiate a series of signal transduction from chloroplasts to whole cells and from locally stressed tissues to the rest of the plant body.These signals trigger a variety of physiological and biochemical reactions intended to mitigate the deleterious effects of high light intensity,such as photodamage and photoinhibition.Light stress protection mechanisms include chloroplastic Reactive oxygen species(ROS)scavenging,chloroplast and stomatal movement,and anthocyanin production.Photosynthetic apparatuses,being the direct targets of photodamage,have also developed various acclimation processes such as thermal energy dissipation through nonphotochemical quenching(NPQ),photorepair of Photosystem II(PSII),and transcriptional regulation of photosynthetic proteins.Fluctuating light is another mild but persistent type of light stress in nature,which unfortunately has been poorly investigated.Current studies,however,suggest that state transitions and cyclic electron transport are the main adaptive mechanisms for mediating fiuctuating light stress in plants.Here,we review the current breadth of knowledge regarding physiological and biochemical responses to both high light stress and fiuctuating light stress.展开更多
Plants face biotic and abiotic stresses during their entire life cycle, which leads to the loss in crop productivity. It has been shown that a relatively shorter exposure to heat stress, called priming, results in bet...Plants face biotic and abiotic stresses during their entire life cycle, which leads to the loss in crop productivity. It has been shown that a relatively shorter exposure to heat stress, called priming, results in better adaptation of plants under subsequent stresses, which plants may face. While rice plants in nature often encounter high temperature stress conditions, the strategies to cope with those are poorly understood. We identified the involvement of microRNA pathways in the adaptation to heat stress (HS) at the physiological and molecular levels. It was observed that osa-miR169 levels are altered after HS and in response to light conditions. Its expression was also regulated by heat priming during anthesis and effectively responds to the successive exposure to high temperature stress during grain filling in rice. Osa-miR169 targets nuclear factor Y (NF-Y). We propose that osa-miR169: NF-Y regulatory module may be important for HS memory induced during high temperature priming and thus may serve to integrate stress responses with light regulated development. The future study in this direction will be useful to understand how plants acclimatize to the changing environment and thus help in generating stress tolerant crops.展开更多
High temperature(HT)accompanied with strong light(SL)often occurs in early indica rice production during grout filling stage in Southern China,which accelerates grain ripening.Two indica rice cultivars with different ...High temperature(HT)accompanied with strong light(SL)often occurs in early indica rice production during grout filling stage in Southern China,which accelerates grain ripening.Two indica rice cultivars with different amylose content(Zhongjiazao17,ZJZ17,high amylose content;Xiangzaoxian45,XZX45,low amylose content)were grown under control(CK),HT,and HT+SL conditions during grout filling to determine the effects on grain yield and quality of rice.The results showed that compared with CK,HT and HT+SL significantly reduced the 1000-grain weight and filled grain rate whether in high or low amylose content early indica rice cultivars during grout filling,resulting in a significantly lower grain yield.Meanwhile,HT and HT+SL significantly decreased the milled rice rate,brown rice rate and head rice rate,whereas significantly increased chalky rate and chalky degree;and breakdown decreased and setback,pasting temperature increased in the cultivars,leading to the poor processing,appearance and cooking and eating quality of early indica rice cultivars.Compared with HT,the yield of ZJZ17 was significantly decreased under HT+SL,due to the lower 1000-grain weight.However,the effect of HT+SL on rice quality varied in the cultivars.In general,the yield and rice quality of ZJZ17 were relatively poor under HT+SL.Our results suggested that HT and HT+SL during grout filling had significant damage to the yield and quality of early indica rice cultivars,especially HT+SL,while the high amylose cultivar ZJZ17 showed a higher negative effect under HT+SL.展开更多
A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light ...A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light induced radical stress is a direct interaction of light with photoreceptors or a secondary mechanism within the pigment epithelium or choroid is in discussion. Among the molecular mechanisms involved are production of reactive oxygen species(ROS), secondary lipid peroxidation, protein oxidation and DNA-damage. The initial trigger to write this review was first a recent finding of our group that the photoreceptor outer segments produce great amounts of ROS and second the detection of ectopic enzymes of the respiratory chainlocalized there- in addition to the hitherto known ROS sources like the visual pigments with their intermediates and the photoreceptor mitochondria harbouring the respiratory chain.展开更多
基金Supported by the Tianjin Excellent Science and Technology Commissioners Project (No.22ZYCGSN00010)the Open Fund of Tianjin Key Laboratory of Aquatic Ecology and Aquaculture (No.TJAE201805)+1 种基金the Open Fund of Key Laboratory of Marine Ecosystem Dynamics (No.MED202013)the Tianjin Natural Science Foundation Project (No.18JCQNJC14800)。
文摘Variation in metabolite profiles of Haematococcus pluvialis(a type of unicellular green algal)under light stress is a key issue of study at the present.To investigate the effect of light intensity on accumulation of astaxanthin in H.pluvialis,a 26-day batch culture experiment of H.pluvialis under the light intensity levels at 73,127,182,236,and 291μmol/(m^(2)·s)was conducted.Therefore,the optimal light intensity and the corresponding metabolic pathways of accumulation in H.pluvialis were determined.Results show that 236μmol/(m^(2)·s)was the optimum light intensity to induce astaxanthin accumulation,at which a maximum content of 9.01 mg/L was achieved on Day 24.A total of 132 metabolites were identified and quantified,of which 38 differential metabolites were highlighted and classified,including 3 fatty acids or intermediates,5 amino acids or derivatives,5 carbohydrates or intermediates,16nucleoside derivatives,and 9 other metabolites using LC-MS/MS technique.Subsequently,16 statistically significant differential metabolic pathways were enriched and annotated based on Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis between the control and the 236μmol/(m^(2)·s)treatment group(P<0.05).In addition,the bioprocesses included cellular basal metabolism and signaling systems,such as carbohydrate metabolism,amino acid metabolism,glycerol and derivatives metabolism,nucleotide and derivative metabolism,and inositol phosphate metabolism were activated and regulated under strong light stress conditions.Moreover,4 hub metabolites containing D-glucose-6-phosphate,L-tyrosine,glycerol-3-phosphate,and L-glutamine were identified,based on which the associated metabolic network was constructed.The study provided a metabolomic view of astaxanthin accumulation in H.pluvialis under strong light stress.
文摘Influence of high light stress on the photosynthesis of flag leaves of indica subspecies (cv. “Shanyou 63', sensitive to photoinhibition) and japonica subspecies (cv. “Wuyujing', resistant to photoinhibition) of rice ( Oryza sativa L.) was comparatively investigated. In both cultivars of rice, the excitation energy distribution between two photosystems was altered and the excitation energy transfer from light harvesting chlorophyll protein complexes to PSⅡ was inhibited by high light stress. These decreases were more pronounced in indica rice cultivar as compared to japonica one. The analysis of mild SDS_PAGE showed that in indica rice, high light stress almost disaggregated the trimer of light harvesting chlorophyll protein complexes of PSⅡ (LHC Ⅱ 1). The stress reduced the contents of internal antennae chlorophyll protein complexes of PSⅡ (CPa), light harvesting chlorophyll protein of PSⅠ (CPⅠa) and Chl a protein complex of PSⅠ reaction center (CPⅠ) as well as dimer of LHCⅡ (LHCⅡ 2) in indica rice. In japonica subspecies, however, high light stress depressed the contents of LHCⅡ 1, CPa and CPⅠa, but slightly impacted on CPⅠ content. Moreover, the increase in the contents of monomer of LHCⅡ by high light stress was found in both subspecies. In consistent with above results, analysis of polypeptide indicated that the amounts of 27 kD and 25 kD polypeptide of LHCⅡ in particular, as well as that of 21 kD polypeptide of CPⅠa were reduced by high light stress in both subspecies. It was found that, comparing with japonica rice, the stress pronouncedly diminished 43 kD and 47 kD proteins of CPa and 23 kD extrisic protein in indica rice.
文摘The oxygen evolution, thermal dissipation, and photochemical energy storage of three hybrid poplar clones, namely the triploid clone B342, the diploid clone B11 [(Populus alba×P. glandulosa)×(P.tomentosa×P.bolleana)], and the triploid clone B346 [(P.tomentosa×P. bolleana)×(P. alba×P.glandulosa)], under light stress were studied using photoacoustics. The oxygen evolution signal and photochemical energy storage varied negatively with the pretreatment_PFD (photon flux density), whereas the thermal signal varied positively with the pretreatment_PFD. Photochemical energy storage was reallocated to PSⅡ more than to PSⅠ, while the photochemical energy storage in PSⅠ was more stable than that in PSⅡ when subjected to light stress. The inhibitors streptomycin (SM), dithiothreitol (DTT) and sodium fluoride (NaF) could all affect the oxygen evolution signal. Clones B11 and B342 were more resistant to light stress than clone B346.
基金supported by grants from the National Natural Science Foundation of China (No.U1205122)Key projects of the Xiamen Southern Ocean Research Center (14GZY70NF34)+1 种基金the Natural Science Foundation of Fujian Province (No.2015J05069)‘Li ShangDa’ Foundation and Innovation Research Team Foundation of Jimei University (No.2010A02)
文摘Large yellow croaker(Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an opportunity of investigating the molecular responding mechanism of teleost in light stress. The gene expression profile of fish under light stress is rarely documented. In this research, the transcriptome profiles of the abdominal skin of L. crocea exposed to light or dark for 0 h, 0.5 h and 2 h were produced by next-generation sequencing(NGS). The cluster results demonstrated that stress period, rather than light intensity(e.g., light or dark), is the major influencing factor. Differently expressed genes(DEGs) were identified between 0 h and 0.5 h groups, between 0 h and 2 h groups, between 0.5 h light and 0.5 h dark, and between 2 h light and 2 h dark, respectively. The gene ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) annotation revealed that the genes relating to immunity, energy metabolism, and cytoskeletal protein binding were significantly enriched. The detailed analysis of transcriptome profiles also revealed regular gene expression trends, indicating that the elaborate gene regulation networks underlined the molecular responses of the fish to light stress. This transcriptome analysis suggested that systematic and complicated regulatory cascades were functionally activated in response to external stress, and coloration change caused by light stress was mainly attributed to the change in the density of chromatophores for L. crocea. This study also provided valuable information for skin coloration or light stress research on other marine fish species.
基金supported by the National Key R&D Program of China (2021YFA0909600)
文摘Plants require solar energy to grow through oxygenic photosynthesis;however,when light intensity exceeds the optimal range for photosynthesis,it causes abiotic stress and physiological damage in plants.In response to high light stress,plants initiate a series of signal transduction from chloroplasts to whole cells and from locally stressed tissues to the rest of the plant body.These signals trigger a variety of physiological and biochemical reactions intended to mitigate the deleterious effects of high light intensity,such as photodamage and photoinhibition.Light stress protection mechanisms include chloroplastic Reactive oxygen species(ROS)scavenging,chloroplast and stomatal movement,and anthocyanin production.Photosynthetic apparatuses,being the direct targets of photodamage,have also developed various acclimation processes such as thermal energy dissipation through nonphotochemical quenching(NPQ),photorepair of Photosystem II(PSII),and transcriptional regulation of photosynthetic proteins.Fluctuating light is another mild but persistent type of light stress in nature,which unfortunately has been poorly investigated.Current studies,however,suggest that state transitions and cyclic electron transport are the main adaptive mechanisms for mediating fiuctuating light stress in plants.Here,we review the current breadth of knowledge regarding physiological and biochemical responses to both high light stress and fiuctuating light stress.
文摘Plants face biotic and abiotic stresses during their entire life cycle, which leads to the loss in crop productivity. It has been shown that a relatively shorter exposure to heat stress, called priming, results in better adaptation of plants under subsequent stresses, which plants may face. While rice plants in nature often encounter high temperature stress conditions, the strategies to cope with those are poorly understood. We identified the involvement of microRNA pathways in the adaptation to heat stress (HS) at the physiological and molecular levels. It was observed that osa-miR169 levels are altered after HS and in response to light conditions. Its expression was also regulated by heat priming during anthesis and effectively responds to the successive exposure to high temperature stress during grain filling in rice. Osa-miR169 targets nuclear factor Y (NF-Y). We propose that osa-miR169: NF-Y regulatory module may be important for HS memory induced during high temperature priming and thus may serve to integrate stress responses with light regulated development. The future study in this direction will be useful to understand how plants acclimatize to the changing environment and thus help in generating stress tolerant crops.
基金the National Key Research&Development Project of China(2016YFD0300501)the Key Project of Jiangxi Provincial Natural Science Foundation(20202ACBL215004)the Key Research of&Development Project Jiangxi Province,China(20171BBF60030).
文摘High temperature(HT)accompanied with strong light(SL)often occurs in early indica rice production during grout filling stage in Southern China,which accelerates grain ripening.Two indica rice cultivars with different amylose content(Zhongjiazao17,ZJZ17,high amylose content;Xiangzaoxian45,XZX45,low amylose content)were grown under control(CK),HT,and HT+SL conditions during grout filling to determine the effects on grain yield and quality of rice.The results showed that compared with CK,HT and HT+SL significantly reduced the 1000-grain weight and filled grain rate whether in high or low amylose content early indica rice cultivars during grout filling,resulting in a significantly lower grain yield.Meanwhile,HT and HT+SL significantly decreased the milled rice rate,brown rice rate and head rice rate,whereas significantly increased chalky rate and chalky degree;and breakdown decreased and setback,pasting temperature increased in the cultivars,leading to the poor processing,appearance and cooking and eating quality of early indica rice cultivars.Compared with HT,the yield of ZJZ17 was significantly decreased under HT+SL,due to the lower 1000-grain weight.However,the effect of HT+SL on rice quality varied in the cultivars.In general,the yield and rice quality of ZJZ17 were relatively poor under HT+SL.Our results suggested that HT and HT+SL during grout filling had significant damage to the yield and quality of early indica rice cultivars,especially HT+SL,while the high amylose cultivar ZJZ17 showed a higher negative effect under HT+SL.
文摘A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light induced radical stress is a direct interaction of light with photoreceptors or a secondary mechanism within the pigment epithelium or choroid is in discussion. Among the molecular mechanisms involved are production of reactive oxygen species(ROS), secondary lipid peroxidation, protein oxidation and DNA-damage. The initial trigger to write this review was first a recent finding of our group that the photoreceptor outer segments produce great amounts of ROS and second the detection of ectopic enzymes of the respiratory chainlocalized there- in addition to the hitherto known ROS sources like the visual pigments with their intermediates and the photoreceptor mitochondria harbouring the respiratory chain.
