Photosynthesis includes the collection of light and the transfer of solar energy using light-harvesting chlorophyll a/b-binding(LHC) proteins.In high plants,the LHC gene family includes LHCA and LHCB sub-families,whic...Photosynthesis includes the collection of light and the transfer of solar energy using light-harvesting chlorophyll a/b-binding(LHC) proteins.In high plants,the LHC gene family includes LHCA and LHCB sub-families,which encode proteins constituting the light-harvesting complex of photosystems I and II.Zostera marina L.is a monocotyledonous angiosperm and inhabits submerged marine environments rather than land environments.We characterized the Lhca and Lhcb gene families of Z.marina from the expressed sequence tags(EST) database.In total,13 unigenes were annotated as Zm Lhc,6 in Lhca family and 7 in Zm Lhcb family.Zm LHCA and Zm LHCB contained the conservative LHC motifs and amino acid residues binding chlorophyll.The average similarity among mature Zm LHCA and Zm LHCB was 48.91% and 48.66%,respectively,which indicated a high degree of divergence within Zm LHChc gene family.The reconstructed phylogenetic tree showed that the tree topology and phylogenetic relationship were similar to those reported in other high plants,suggesting that the Lhc genes were highly conservative and the classification of Zm Lhc genes was consistent with the evolutionary position of Z.marina.Real-time reverse transcription(RT) PCR analysis showed that different members of Zm Lhca and Zm Lhcb responded to a stress in different expression patterns.Salinity,temperature,light intensity and light quality may affect the expression of most Zm Lhca and Zm Lhcb genes.Inorganic carbon concentration and acidity had no obvious effect on Zm Lhca and Zm Lhcb gene expression,except for Zm Lhca6.展开更多
The light harvesting chlorophyll a/b-binding protein is one of key proteins in the transformation from light energy to chemical energy. An open reading frame coding precursor protein of cab gene was cloned from the fi...The light harvesting chlorophyll a/b-binding protein is one of key proteins in the transformation from light energy to chemical energy. An open reading frame coding precursor protein of cab gene was cloned from the first strand of bamboo cDNA through RT-PCR methods,and named as cab-PhE1 (cab gene 1 from Phyllostachys edulis EF207229). The sequence analysis showed that the deduced polypeptide was highly homologous to some other CAB proteins from monocotyledon,and the gene belonged to lhcb2 family. Tissue specific expression showed that cab-PhE1 expressed higher in leaf than sheath and stem. The prokaryotic expression vector of cab-PhE1 gene encoding the mature protein was constructed by subcloning the fragment into pET-23 a and was expressed in Escherichia coli induced by IPTG. The molecular weight of the induced protein was about 28 ku,approximate to that of the mature protein. This work is a key to the further research on in vitro reconstitution of light-harvesting Chl a/b complexes.展开更多
The nuclear-encoded light-harvesting chlorophyll a/b-binding proteins(LHCPs) are specifically translocated from the stroma into the thylakoid membrane through the chloroplast signal recognition particle(cp SRP) pa...The nuclear-encoded light-harvesting chlorophyll a/b-binding proteins(LHCPs) are specifically translocated from the stroma into the thylakoid membrane through the chloroplast signal recognition particle(cp SRP) pathway. The cp SRP is composed of a cp SRP43 protein and a cp SRP54 protein, and it forms a soluble transit complex with LHCP in the chloroplast stroma. Here, we identified the YGL9 gene that is predicted to encode the probable rice cp SRP43 protein from a rice yellow-green leaf mutant. A phylogenetic tree showed that an important conserved protein family, cp SRP43, is present in almost all green photosynthetic organisms such as higher plants and green algae. Sequence analysis showed that YGL9 comprises a chloroplast transit peptide, three chromodomains and four ankyrin repeats, and the chromodomains and ankyrin repeats are probably involved in protein-protein interactions. Subcellular localization showed that YGL9 is localized in the chloroplast. Expression pattern analysis indicated that YGL9 is mainly expressed in green leaf sheaths and leaves. Quantitative real-time PCR analysis showed that the expression levels of genes associated with pigment metabolism, chloroplast development and photosynthesis were distinctly affected in the ygl9 mutant. These results indicated that YGL9 is possibly involved in pigment metabolism, chloroplast development and photosynthesis in rice.展开更多
After saturating light illumination for 3 h the potential photochemical efficiency of photosystem Ⅱ (PSII) (FJF,, the ratio of variable to maximal fluorescence) decreased markedly and recovered basically to the l...After saturating light illumination for 3 h the potential photochemical efficiency of photosystem Ⅱ (PSII) (FJF,, the ratio of variable to maximal fluorescence) decreased markedly and recovered basically to the level before saturating light illumination after dark recovery for 3 h in both soybean and wheat leaves, indicating that the decline in FJ/Fm is a reversible down-regulation. Also, the saturating light illumination led to significant decreases in the low temperature (77 K) chlorophyll fluorescence parameters F685 (chlorophyll a fluorescence peaked at 685 nm) and F685/F735 (F735, chlorophyll a fluorescence peaked at 735 nm) in soybean leaves but not in wheat leaves. Moreover, trypsin (a protease) treatment resulted in a remarkable decrease in the amounts of PsbS protein (a nuclear gene psbS-encoded 22 kDa protein) in the thylakoids from saturating light-illuminated (SI), but not in those from darkadapted (DT) and dark-recovered (DRT) soybean leaves. However, the treatment did not cause such a decrease in amounts of the PsbS protein in the thylakoids from saturating light-illuminated wheat leaves. These results support the conclusion that saturating light illumination induces a reversible dissociation of some light-harvesting complex Ⅱ (LHClI) from PSII reaction center complex in soybean leaf but not in wheat leaf.展开更多
THE photosystem Ⅱ light-harvesting chlorophyll a/b protein complex (LHC Ⅱ) is a kind of integral membrane protein complex in the thylakoid membranes of chloroplasts from higher plants and green algae, and its most i...THE photosystem Ⅱ light-harvesting chlorophyll a/b protein complex (LHC Ⅱ) is a kind of integral membrane protein complex in the thylakoid membranes of chloroplasts from higher plants and green algae, and its most important biological function is light harvesting and展开更多
基金supported by the Key Science and Technology Program of Shandong Province (Grant no.2012GHY11527)the Public Science and Technology Research Funds Projects of Ocean,State Oceanic Administration of China (Grant no.201105021)
文摘Photosynthesis includes the collection of light and the transfer of solar energy using light-harvesting chlorophyll a/b-binding(LHC) proteins.In high plants,the LHC gene family includes LHCA and LHCB sub-families,which encode proteins constituting the light-harvesting complex of photosystems I and II.Zostera marina L.is a monocotyledonous angiosperm and inhabits submerged marine environments rather than land environments.We characterized the Lhca and Lhcb gene families of Z.marina from the expressed sequence tags(EST) database.In total,13 unigenes were annotated as Zm Lhc,6 in Lhca family and 7 in Zm Lhcb family.Zm LHCA and Zm LHCB contained the conservative LHC motifs and amino acid residues binding chlorophyll.The average similarity among mature Zm LHCA and Zm LHCB was 48.91% and 48.66%,respectively,which indicated a high degree of divergence within Zm LHChc gene family.The reconstructed phylogenetic tree showed that the tree topology and phylogenetic relationship were similar to those reported in other high plants,suggesting that the Lhc genes were highly conservative and the classification of Zm Lhc genes was consistent with the evolutionary position of Z.marina.Real-time reverse transcription(RT) PCR analysis showed that different members of Zm Lhca and Zm Lhcb responded to a stress in different expression patterns.Salinity,temperature,light intensity and light quality may affect the expression of most Zm Lhca and Zm Lhcb genes.Inorganic carbon concentration and acidity had no obvious effect on Zm Lhca and Zm Lhcb gene expression,except for Zm Lhca6.
文摘The light harvesting chlorophyll a/b-binding protein is one of key proteins in the transformation from light energy to chemical energy. An open reading frame coding precursor protein of cab gene was cloned from the first strand of bamboo cDNA through RT-PCR methods,and named as cab-PhE1 (cab gene 1 from Phyllostachys edulis EF207229). The sequence analysis showed that the deduced polypeptide was highly homologous to some other CAB proteins from monocotyledon,and the gene belonged to lhcb2 family. Tissue specific expression showed that cab-PhE1 expressed higher in leaf than sheath and stem. The prokaryotic expression vector of cab-PhE1 gene encoding the mature protein was constructed by subcloning the fragment into pET-23 a and was expressed in Escherichia coli induced by IPTG. The molecular weight of the induced protein was about 28 ku,approximate to that of the mature protein. This work is a key to the further research on in vitro reconstitution of light-harvesting Chl a/b complexes.
文摘与野生型油菜相比 ,叶绿素缺乏油菜突变体 Cr35 2 9L HC 多肽组成并未发生改变 ,但其含量却都明显降低 .RNA印迹及点杂交结果都显示出 Cr35 2 9cab基因的转录增加 .这些结果表明 :该叶绿素缺乏突变体仅影响L HC 多肽的蛋白含量 ;并未影响其组成 ;突变体 L HC 蛋白量的减少并非 cab基因转录降低所致 .可见转录水平的调节仅对 L HC 在类囊体膜上的积累起有限作用 ;
基金supported by the Special Fund for Industry of Ministry of Agriculture of China (201303129)the Fundamental Research Funds for the Central Universities, China (XDJK2013A023)+1 种基金the Key Program of Chongqing, China (cstc2012ggC 80002)the Upgrade Project of the Key Laboratory of Chongqing, China (cstc2014pt-sy80001)
文摘The nuclear-encoded light-harvesting chlorophyll a/b-binding proteins(LHCPs) are specifically translocated from the stroma into the thylakoid membrane through the chloroplast signal recognition particle(cp SRP) pathway. The cp SRP is composed of a cp SRP43 protein and a cp SRP54 protein, and it forms a soluble transit complex with LHCP in the chloroplast stroma. Here, we identified the YGL9 gene that is predicted to encode the probable rice cp SRP43 protein from a rice yellow-green leaf mutant. A phylogenetic tree showed that an important conserved protein family, cp SRP43, is present in almost all green photosynthetic organisms such as higher plants and green algae. Sequence analysis showed that YGL9 comprises a chloroplast transit peptide, three chromodomains and four ankyrin repeats, and the chromodomains and ankyrin repeats are probably involved in protein-protein interactions. Subcellular localization showed that YGL9 is localized in the chloroplast. Expression pattern analysis indicated that YGL9 is mainly expressed in green leaf sheaths and leaves. Quantitative real-time PCR analysis showed that the expression levels of genes associated with pigment metabolism, chloroplast development and photosynthesis were distinctly affected in the ygl9 mutant. These results indicated that YGL9 is possibly involved in pigment metabolism, chloroplast development and photosynthesis in rice.
基金National Key R&D Program of China(2019YFA0903902)National Natural Science Foundation of China(32270595)Shenzhen Science and Technology Program(JCYJ20190808115005598)。
文摘After saturating light illumination for 3 h the potential photochemical efficiency of photosystem Ⅱ (PSII) (FJF,, the ratio of variable to maximal fluorescence) decreased markedly and recovered basically to the level before saturating light illumination after dark recovery for 3 h in both soybean and wheat leaves, indicating that the decline in FJ/Fm is a reversible down-regulation. Also, the saturating light illumination led to significant decreases in the low temperature (77 K) chlorophyll fluorescence parameters F685 (chlorophyll a fluorescence peaked at 685 nm) and F685/F735 (F735, chlorophyll a fluorescence peaked at 735 nm) in soybean leaves but not in wheat leaves. Moreover, trypsin (a protease) treatment resulted in a remarkable decrease in the amounts of PsbS protein (a nuclear gene psbS-encoded 22 kDa protein) in the thylakoids from saturating light-illuminated (SI), but not in those from darkadapted (DT) and dark-recovered (DRT) soybean leaves. However, the treatment did not cause such a decrease in amounts of the PsbS protein in the thylakoids from saturating light-illuminated wheat leaves. These results support the conclusion that saturating light illumination induces a reversible dissociation of some light-harvesting complex Ⅱ (LHClI) from PSII reaction center complex in soybean leaf but not in wheat leaf.
文摘THE photosystem Ⅱ light-harvesting chlorophyll a/b protein complex (LHC Ⅱ) is a kind of integral membrane protein complex in the thylakoid membranes of chloroplasts from higher plants and green algae, and its most important biological function is light harvesting and