Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplificatio...Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplification of cDNA ends（RACE） technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, including a 5′ untranslated region（UTR） of 92 bp, a 3′？UTR of 69 bp, and an open reading frame（ORF） of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR revealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.展开更多
Enhancing photosynthetic efficiency is a major goal for improving crop yields under agricultural field conditions and is associated with chloroplast biosynthesis and development.In this study,we demonstrate that Golde...Enhancing photosynthetic efficiency is a major goal for improving crop yields under agricultural field conditions and is associated with chloroplast biosynthesis and development.In this study,we demonstrate that Golden2-like 1a(BnGLK1a)plays an important role in regulating chloroplast development and photosynthetic efficiency.Overexpressing BnGLK1a resulted in significant increases in chlorophyll content,the number of thylakoid membrane layers and photosynthetic efficiency in Brassica napus,while knocking down BnGLK1a transcript levels through RNA interference(RNAi)had the opposite effects.A yeast two-hybrid screen revealed that BnGLK1a interacts with the abscisic acid receptor PYRABACTIN RESISTANCE 1-LIKE 1-2(BnPYL1-2)and CONSTITUTIVE PHOTOMORPHOGENIC 9 SIGNALOSOME 5A subunit(BnCSN5A),which play essential roles in regulating chloroplast development and photosynthesis.Consistent with this,BnGLK1a-RNAi lines of B.napus display hypersensitivity to the abscisic acid(ABA)response.Importantly,overexpression of BnGLK1a resulted in a 10%increase in thousand-seed weight,whereas seeds from BnGLK1a-RNAi lines were 16%lighter than wild type.We propose that BnGLK1a could be a potential target in breeding for improving rapeseed productivity.Our results not only provide insights into the mechanisms of BnGLK1a function,but also offer a potential approach for improving the productivity of Brassica species.展开更多
Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that ...Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR is a chloroplast protein. Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type.Moreover, we found that the RNA editing efficiencies of ndhA-1019 and rpl2-1 were significantly reduced in the OsDXR knock-out lines. Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay. Finally, disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway resulted in defects in chloroplast development and the RNA editing of chloroplast genes.展开更多
The nuclear-encoded factors and the photosynthetic apparatus have been studied extensively during chloroplast biogenesis.However,many questions regarding these processes remain unanswered,particularly in perennial woo...The nuclear-encoded factors and the photosynthetic apparatus have been studied extensively during chloroplast biogenesis.However,many questions regarding these processes remain unanswered,particularly in perennial woody plants.As a model material of woody plants,poplar not only has very significant value of research,but also possesses economic and ecological properties.This study reports the Populus trichocarpa DJ-1C(PtrDJ1C)factor,encoded by a nuclear gene,and a member of the DJ-1 superfamily.PtrDJ1C knock-out with the CRISPR/Cas9 system resulted in different albino phenotypes.Chlorophyll fluorescence and immunoblot analyses showed that the levels of photosynthetic complex proteins decreased significantly.Moreover,the transcript level of plastid-encoded RNA polymerase-dependent genes and the splicing efficiency of several introns were affected in the mutant line.Furthermore,rRNA accumulation was abnormal,leading to developmental defects in chloroplasts and affecting lignin accumulation.We concluded that the PtrDJ1C protein is essential for early chloroplast development and lignin deposition in poplar.展开更多
In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thrombox...In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thromboxane B（TXB<sub>2</sub>）and 6-keto-PGF<sub>1α</sub> in plasma weremeasured during open-heart surgery.Quantitative study of myocardial ultrastructure and obser-vation of cardiac resuscitation were also undertaken.The findings suggested that FDP,especiallywhen combined with Cap could significantly strengthen the protective effects of cold potassiumcardioplegia solution on ischemic myocardium.展开更多
Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of ...Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of glucose to inorganic phosphorus(Pi)10:1.Addition ofAMP was found to be very beneficial to the FDP production.A multienzyme system model for FDPaccumulation was developed,in which FDP was regarded as a substrate of phosphor-fructokinase(PFK),to simulate the activation effect of FDP on PFK.The model simulations were in good agree-ment with the experimental data.展开更多
It has been reported that Arabidopsis chloroplast accD transcripts undergo RNA editing and that loss of accD-C794 RNA editing does not affect plant growth under normal conditions.To date,the exact biological role of a...It has been reported that Arabidopsis chloroplast accD transcripts undergo RNA editing and that loss of accD-C794 RNA editing does not affect plant growth under normal conditions.To date,the exact biological role of accD-C794 editing has remained elusive.Here,we reveal an unexpected role for accD-C794 editing in response to heat stress.Loss of accD-C794 editing results in a yellow and dwarf phenotype with decreased chloroplast gene expression under heat stress,and artificial improvement of C794-edited accD gene expression enhances heat tolerance in Arabidopsis.These data suggest that accD-C794 editing confers heat tolerance in planta.We also found that treatment with the product of acetyl coenzyme A carboxylase(ACCase)could allay mutant phenotypic characteristics and showed that a mutation in the CAC3 gene for the a-subunit of ACCase was associated with dwarfism under heat stress.These observations indicate that defective accD-C794 editing may be intrinsic to reduced ACCase activity,thereby contributing to heat sensitivity.ACCase catalyzes the committed step of de novo fatty acid(FA)biosynthesis.FA content analysis revealed that unsaturated oleic(C18:1)and linoleic acids(C18:2)were low in the accD-C794 editing-defective mutant but high in the C794-edited accD-overexpressing plants compared with the wild type.Supplying exogenous C18:1 and C18:2 could rescue the mutant phenotype,suggesting that these FAs play an essential role in tolerance to heat stress.Transmission electron microscopy observations showed that heat stress seriously affected the membrane architecture in accD editing-defective mutants but not in accD-overexpressing plants.These results provide the first evidence that accD-C794 editing regulates FA biosynthesis for maintenance of membrane structural homeostasis under heat stress.展开更多
基金The National Natural Science Foundation of China under contract Nos 41176151 and 41276177the National High Technology Research&Development Program of China under contract No.2012AA100811the Funds for Distinguished Young Scientists of Fujian Province of China under contract No.2010J06016
文摘Fructose-1,6-bisphosphatase（FBPase） is one of the key enzymes in Calvin circle and starch biosynthesis. In this study, the full-length of cpFBPase gene from Pyropia haitanensis was cloned by using rapid amplification of cDNA ends（RACE） technology. The nucleotide sequence of PhcpFBPase consists of 1 400 bp, including a 5′ untranslated region（UTR） of 92 bp, a 3′？UTR of 69 bp, and an open reading frame（ORF） of 1 236 bp, which can be translated into a 412-amino-acid putative peptides with a molecular weight of 44.3 kDa and a theoretical pI of 5.23. Multiple sequence alignment indicated that the protein belonged to the chloroplast FBPase enzyme. Phylogenetic analysis showed that the protein assembled with the cpFBPase of a thermal tolerant unicellular red micro-algae Galdieria sulphuraria. Expression patterns analyzed by qRT-PCR revealed that the expression of PhcpFBPase gene in the thallus phage was 7-fold higher than in the conchocelis phage, which suggested the different mechanisms of inorganic carbon utilization among the different life phages of P. haitanensis. And the different response modes of PhcpFBPase mRNA levels to high temperature and desiccation stress indicated that PhcpFBPase played an important role in responsing to abiotic stress.
基金This work was funded by the National Natural Science Foundation of China(32172597 and 31830067)the Chongqing Talents of Exceptional Young Talents Project,China(CQYC202005097,cstc2021ycjh-bgzxm0204,and cstc2021jcyj-bshX0002)+2 种基金the China Agriculture Research System of MOF and MARA(CARS-12)the 111 Project,China(B12006)the Germplasm Creation Special Program of Southwest University,China。
文摘Enhancing photosynthetic efficiency is a major goal for improving crop yields under agricultural field conditions and is associated with chloroplast biosynthesis and development.In this study,we demonstrate that Golden2-like 1a(BnGLK1a)plays an important role in regulating chloroplast development and photosynthetic efficiency.Overexpressing BnGLK1a resulted in significant increases in chlorophyll content,the number of thylakoid membrane layers and photosynthetic efficiency in Brassica napus,while knocking down BnGLK1a transcript levels through RNA interference(RNAi)had the opposite effects.A yeast two-hybrid screen revealed that BnGLK1a interacts with the abscisic acid receptor PYRABACTIN RESISTANCE 1-LIKE 1-2(BnPYL1-2)and CONSTITUTIVE PHOTOMORPHOGENIC 9 SIGNALOSOME 5A subunit(BnCSN5A),which play essential roles in regulating chloroplast development and photosynthesis.Consistent with this,BnGLK1a-RNAi lines of B.napus display hypersensitivity to the abscisic acid(ABA)response.Importantly,overexpression of BnGLK1a resulted in a 10%increase in thousand-seed weight,whereas seeds from BnGLK1a-RNAi lines were 16%lighter than wild type.We propose that BnGLK1a could be a potential target in breeding for improving rapeseed productivity.Our results not only provide insights into the mechanisms of BnGLK1a function,but also offer a potential approach for improving the productivity of Brassica species.
基金supported by the Program for Subsidized Project of Suzhou Academy of Agricultural Sciences,China(20028)the Science and Technology Foundation of Suzhou(SNG2020048)+3 种基金the Huaishang Talents,China,the National Natural Science Foundation of China(32070345)the Huai’an Academy of Agricultural Sciences Initiation and Development of Scientific Research Fund for High-level Introduced Talents,China(0062019016B)the Six Talents Summit Project of Jiangsu Province,China(NY-129)the Natural Science Foundation of Jiangsu Province,China(BK20190239 and BK20180107)。
文摘Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR is a chloroplast protein. Many genes involved in chlorophyll biosynthesis and chloroplast development were differentially expressed in the OsDXR knock-out lines compared to the wild type.Moreover, we found that the RNA editing efficiencies of ndhA-1019 and rpl2-1 were significantly reduced in the OsDXR knock-out lines. Furthermore, OsDXR interacted with the RNA editing factor OsMORF1 in a yeast two-hybrid screen and bimolecular fluorescence complementation assay. Finally, disruption of the plastidial 2-C-methyl-derythritol-4-phosphate pathway resulted in defects in chloroplast development and the RNA editing of chloroplast genes.
基金supported by the National Natural Science Foundation of China(Grant Nos.32201516,91954202)the Youth Top-notch Talent Program of Hebei Education Department(BJK2022028)+1 种基金National Training Program of Innovation and Entrepreneurship for Undergraduates(Grant Nos.S202110022037,G202010022075)the funding of Hebei North University(XJ2021013)。
文摘The nuclear-encoded factors and the photosynthetic apparatus have been studied extensively during chloroplast biogenesis.However,many questions regarding these processes remain unanswered,particularly in perennial woody plants.As a model material of woody plants,poplar not only has very significant value of research,but also possesses economic and ecological properties.This study reports the Populus trichocarpa DJ-1C(PtrDJ1C)factor,encoded by a nuclear gene,and a member of the DJ-1 superfamily.PtrDJ1C knock-out with the CRISPR/Cas9 system resulted in different albino phenotypes.Chlorophyll fluorescence and immunoblot analyses showed that the levels of photosynthetic complex proteins decreased significantly.Moreover,the transcript level of plastid-encoded RNA polymerase-dependent genes and the splicing efficiency of several introns were affected in the mutant line.Furthermore,rRNA accumulation was abnormal,leading to developmental defects in chloroplasts and affecting lignin accumulation.We concluded that the PtrDJ1C protein is essential for early chloroplast development and lignin deposition in poplar.
基金The project was supported by the National Natural Science Foundation of China No.3880772
文摘In the present experiment,fructose-1,6-diphosphate（FDP）and captopril（Cap）wereadded to the cold potassium cardioplegia solution and the levels of malondialdehyde（MDA）,cre-atine phosphokinase MB（CPK-MB）,thromboxane B（TXB<sub>2</sub>）and 6-keto-PGF<sub>1α</sub> in plasma weremeasured during open-heart surgery.Quantitative study of myocardial ultrastructure and obser-vation of cardiac resuscitation were also undertaken.The findings suggested that FDP,especiallywhen combined with Cap could significantly strengthen the protective effects of cold potassiumcardioplegia solution on ischemic myocardium.
基金Supported by the National Natural Science Foundation of China
文摘Permeable yeast cells were used in the batch production of fructose-1,6-diphosphate(FDP).The optimum reaction conditions were reported to be:reaction temperature 30℃,tolueneconcentration 8%(V/V),and initial ratio of glucose to inorganic phosphorus(Pi)10:1.Addition ofAMP was found to be very beneficial to the FDP production.A multienzyme system model for FDPaccumulation was developed,in which FDP was regarded as a substrate of phosphor-fructokinase(PFK),to simulate the activation effect of FDP on PFK.The model simulations were in good agree-ment with the experimental data.
基金supported by the National Natural Science Foundation of China(91317312 and 31900387)the Natural Science Foundation of Hunan Province(2020JJ4037 and 2021JJ40243).
文摘It has been reported that Arabidopsis chloroplast accD transcripts undergo RNA editing and that loss of accD-C794 RNA editing does not affect plant growth under normal conditions.To date,the exact biological role of accD-C794 editing has remained elusive.Here,we reveal an unexpected role for accD-C794 editing in response to heat stress.Loss of accD-C794 editing results in a yellow and dwarf phenotype with decreased chloroplast gene expression under heat stress,and artificial improvement of C794-edited accD gene expression enhances heat tolerance in Arabidopsis.These data suggest that accD-C794 editing confers heat tolerance in planta.We also found that treatment with the product of acetyl coenzyme A carboxylase(ACCase)could allay mutant phenotypic characteristics and showed that a mutation in the CAC3 gene for the a-subunit of ACCase was associated with dwarfism under heat stress.These observations indicate that defective accD-C794 editing may be intrinsic to reduced ACCase activity,thereby contributing to heat sensitivity.ACCase catalyzes the committed step of de novo fatty acid(FA)biosynthesis.FA content analysis revealed that unsaturated oleic(C18:1)and linoleic acids(C18:2)were low in the accD-C794 editing-defective mutant but high in the C794-edited accD-overexpressing plants compared with the wild type.Supplying exogenous C18:1 and C18:2 could rescue the mutant phenotype,suggesting that these FAs play an essential role in tolerance to heat stress.Transmission electron microscopy observations showed that heat stress seriously affected the membrane architecture in accD editing-defective mutants but not in accD-overexpressing plants.These results provide the first evidence that accD-C794 editing regulates FA biosynthesis for maintenance of membrane structural homeostasis under heat stress.
