We studied the difference in thermostability of photosystem Ⅱ （PSII） and leaf lipid composition between a T-DNA insertion mutant rice （Oryza sativa L.） VG28 and its wild type Zhonghuau. Native green gel and SDS-P...We studied the difference in thermostability of photosystem Ⅱ （PSII） and leaf lipid composition between a T-DNA insertion mutant rice （Oryza sativa L.） VG28 and its wild type Zhonghuau. Native green gel and SDS-PAGE electrophoreses revealed that the mutant VG28 lacked all light-harvesting chlorophyll a/b protein complexes. Both the mutant and wild type were sensitive to high temperatures, and the maximal efficiency of PSII photochemistry （FJ Fm） and oxygen-evolving activity of PSII in leaves significantly decreased with increasing temperature. However, the PSII activity of the mutant was markedly more sensitive to high temperatures than that of the wild type. Lipid composition analysis showed that the mutant had less phosphatidylglycerol and sulfoquinovosyl diacylglycerol compared with the wild type. Fatty acid analysis revealed that the mutant had an obvious decrease in the content of 16：1t and a marked increase in the content of 18：3 compared with the wild type. The effects of lipid composition and unsaturation of membrane lipids on the thermostability of PSII are discussed.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
根据日本晴cab4基因序列(GenBank:AK104499.1)设计引物,用RT-PCR的方法从籼稻9311中克隆了叶绿素a/b结合蛋白基因的全长cDNA,命名为cab-9311(cab gene from 9311)。insilico分析表明:cab-9311与cab4基因同源性为99%,编码的蛋白含有244...根据日本晴cab4基因序列(GenBank:AK104499.1)设计引物,用RT-PCR的方法从籼稻9311中克隆了叶绿素a/b结合蛋白基因的全长cDNA,命名为cab-9311(cab gene from 9311)。insilico分析表明:cab-9311与cab4基因同源性为99%,编码的蛋白含有244个氨基酸,与cab4基因编码的蛋白同源性为98%。蛋白分子质量为26.9kD,理论等电点为6.52。第54位～第216位氨基酸是一个典型的叶绿素a/b结合蛋白功能域(chlorophyll a/bbinding domain)。跨膜分析和蛋白质三级预测显示,该蛋白在C端有一个典型的跨膜区。亚细胞定位分析表明该蛋白定位于叶绿体,是一个叶绿体内囊体膜上的锚定蛋白。展开更多
文摘We studied the difference in thermostability of photosystem Ⅱ （PSII） and leaf lipid composition between a T-DNA insertion mutant rice （Oryza sativa L.） VG28 and its wild type Zhonghuau. Native green gel and SDS-PAGE electrophoreses revealed that the mutant VG28 lacked all light-harvesting chlorophyll a/b protein complexes. Both the mutant and wild type were sensitive to high temperatures, and the maximal efficiency of PSII photochemistry （FJ Fm） and oxygen-evolving activity of PSII in leaves significantly decreased with increasing temperature. However, the PSII activity of the mutant was markedly more sensitive to high temperatures than that of the wild type. Lipid composition analysis showed that the mutant had less phosphatidylglycerol and sulfoquinovosyl diacylglycerol compared with the wild type. Fatty acid analysis revealed that the mutant had an obvious decrease in the content of 16：1t and a marked increase in the content of 18：3 compared with the wild type. The effects of lipid composition and unsaturation of membrane lipids on the thermostability of PSII are discussed.
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.
