A transformation procedure of choline monooxygenase(CMO) gene, involved in stress tolerance, was established in white pine embryogenic tissue by using A. tumefaciens C58/pMP90. The CMO cDNA fragment(1.3 kb) was genera...A transformation procedure of choline monooxygenase(CMO) gene, involved in stress tolerance, was established in white pine embryogenic tissue by using A. tumefaciens C58/pMP90. The CMO cDNA fragment(1.3 kb) was generated by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) with primers based on the report sequence of CMO in gene bank. A chimerical gene composed of the cauliflower mosaic virus (CaMV) 35S promoter fused to CMO cDNA and β-glucuronidase (GUS-marker gene) was transferred into Ti-derived disarmed binary vector pBI121. The new vector, p35SCMOp, was transferred into Agrobacterium tumefaciens C58/pMP90 by freeze-thaw method. Somatic embryogenesis (SE) initiation of Pinus. Strobus L. and Pinus.Koraiensis Sieb. et Zucc. depended on the manipulation of plant growth regulator (PGR) concentrations in the GLH culture medium. Transgenic embryos and regenerated plants of two Pine species were produced after co-culture of embryogenic tissue with the disarmed strain of A. tumefaciens C58/pMP90/ p35SCMOp and selected on medium containing 25mg/L kanamycin. The transformed embryogenic tissue was initially confirmed by histochemical GUS assay followed by PCR. One copy of T-DNA was detected by transgenic lines analysis in Pinus. Strobus L. and transgenic plants were regenerated for two species using modified protocols for maturation and germination of somatic embryos.展开更多
Betaine is a very effective osmoprotectant found in many organisms. In high plants, betaine is synthesized by oxidation of choline in two sequential steps: choline-->betaine aldehyde-->betaine. The first step is...Betaine is a very effective osmoprotectant found in many organisms. In high plants, betaine is synthesized by oxidation of choline in two sequential steps: choline-->betaine aldehyde-->betaine. The first step is catalyzed by choline monooxygenase (CMO). In this study, the full-length CMO cDNA (1 820 bp) was cloned from halophyte Suaeda liaotungensis Kitag by RT-PCR and RACE. It included a 123 bp 5' UTR, a 368 bp 3' UTR and a 1 329 bp open reading frame encoding a 442-amino-acid polypeptide with 77%, 72% and 74% sequence identity compared to CMOs from spinach, sugar beet and Atriplex hortensis, respectively. The CMO open reading frame (ORF) was cloned and the plant expression vector pBI121-CMO was constructed. It was transferred into tobacco ( Nicotiana tabacum L. ev. 89) via Agrobacterium mediation. PCR and Southern blotting analysis showed that the CMO gene was integrated into tobacco genome. Transgenic tobacco plants contained higher amount of betaine than that of control plants and were able to survive on MS medium containing 250 mmol/L NaCl. Relative electronic conductivity demonstrated less membrane damage in transgenic plants as in the wild type.展开更多
Plants synthesize the osmoprotectant glycine betaine (GB) via choline→betaine aldehyde→glycine be- taine[1]. Two enzymes are involved in the pathway choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BA...Plants synthesize the osmoprotectant glycine betaine (GB) via choline→betaine aldehyde→glycine be- taine[1]. Two enzymes are involved in the pathway choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH). A full length CMO cDNA (1,643bp) was cloned from Amaranthus tricolor. The open reading frame encoded a 442-amino acid polypeptide, which showed 69% identity with CMOs in Spina- cia oleracea L. and Beta vulgaris L. DNA gel blot analysis indicated the presence of one copy of CMO gene in the A. tricolor genome. The expressions of CMO and BADH proteins in A.tricolor leaves significantly increased under salinization, drought and heat stress (42℃), as determined by immunoblot analysis, but did not respond to cold stress (4℃), or exogenous ABA application. The increase of GB content in leaves was parallel to CMO and BADH contents.展开更多
Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a speci...Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.展开更多
The 5＇-flanking proximal region of stress-induced gene encoding choline monooxygenase （CMO） was isolated by Adaptor-PCR and TAIL-PCR from halophyte Suaeda liaotungensis K. A total of 2,204 bp DNA sequence was obtai...The 5＇-flanking proximal region of stress-induced gene encoding choline monooxygenase （CMO） was isolated by Adaptor-PCR and TAIL-PCR from halophyte Suaeda liaotungensis K. A total of 2,204 bp DNA sequence was obtained. The transcription start site, which is located at 128 bp upstream to the start ATG, was predicted by the TSSP-TCM program. The functional elements were analysed by PLACE program. The obtained SICMO gene promoter contains the basic elements： TATA-box, CAAT-box, and stress-induced elements, for example, salt responsive element （GAAAAA）, cold responsive elements （CANNTG）, ABA （Abscisic Acid） responsive elements （NAACAA）, water stress element （CGGTTG）, and WUN responsive elements （GTTAGGTTC）. Isolation and analysis of the promoter of the CMO gene from S. liaotungensis lays a foundation for characterising the stress-induced promoter elements, studying the relationship between the structure and function of the promoter, and investigating the molecular mechanism of CMO gene regulation.展开更多
文摘A transformation procedure of choline monooxygenase(CMO) gene, involved in stress tolerance, was established in white pine embryogenic tissue by using A. tumefaciens C58/pMP90. The CMO cDNA fragment(1.3 kb) was generated by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) with primers based on the report sequence of CMO in gene bank. A chimerical gene composed of the cauliflower mosaic virus (CaMV) 35S promoter fused to CMO cDNA and β-glucuronidase (GUS-marker gene) was transferred into Ti-derived disarmed binary vector pBI121. The new vector, p35SCMOp, was transferred into Agrobacterium tumefaciens C58/pMP90 by freeze-thaw method. Somatic embryogenesis (SE) initiation of Pinus. Strobus L. and Pinus.Koraiensis Sieb. et Zucc. depended on the manipulation of plant growth regulator (PGR) concentrations in the GLH culture medium. Transgenic embryos and regenerated plants of two Pine species were produced after co-culture of embryogenic tissue with the disarmed strain of A. tumefaciens C58/pMP90/ p35SCMOp and selected on medium containing 25mg/L kanamycin. The transformed embryogenic tissue was initially confirmed by histochemical GUS assay followed by PCR. One copy of T-DNA was detected by transgenic lines analysis in Pinus. Strobus L. and transgenic plants were regenerated for two species using modified protocols for maturation and germination of somatic embryos.
文摘Betaine is a very effective osmoprotectant found in many organisms. In high plants, betaine is synthesized by oxidation of choline in two sequential steps: choline-->betaine aldehyde-->betaine. The first step is catalyzed by choline monooxygenase (CMO). In this study, the full-length CMO cDNA (1 820 bp) was cloned from halophyte Suaeda liaotungensis Kitag by RT-PCR and RACE. It included a 123 bp 5' UTR, a 368 bp 3' UTR and a 1 329 bp open reading frame encoding a 442-amino-acid polypeptide with 77%, 72% and 74% sequence identity compared to CMOs from spinach, sugar beet and Atriplex hortensis, respectively. The CMO open reading frame (ORF) was cloned and the plant expression vector pBI121-CMO was constructed. It was transferred into tobacco ( Nicotiana tabacum L. ev. 89) via Agrobacterium mediation. PCR and Southern blotting analysis showed that the CMO gene was integrated into tobacco genome. Transgenic tobacco plants contained higher amount of betaine than that of control plants and were able to survive on MS medium containing 250 mmol/L NaCl. Relative electronic conductivity demonstrated less membrane damage in transgenic plants as in the wild type.
文摘Plants synthesize the osmoprotectant glycine betaine (GB) via choline→betaine aldehyde→glycine be- taine[1]. Two enzymes are involved in the pathway choline monooxygenase (CMO) and betaine aldehyde dehydrogenase (BADH). A full length CMO cDNA (1,643bp) was cloned from Amaranthus tricolor. The open reading frame encoded a 442-amino acid polypeptide, which showed 69% identity with CMOs in Spina- cia oleracea L. and Beta vulgaris L. DNA gel blot analysis indicated the presence of one copy of CMO gene in the A. tricolor genome. The expressions of CMO and BADH proteins in A.tricolor leaves significantly increased under salinization, drought and heat stress (42℃), as determined by immunoblot analysis, but did not respond to cold stress (4℃), or exogenous ABA application. The increase of GB content in leaves was parallel to CMO and BADH contents.
文摘Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.
基金This work was supported by the National Natural Sciences Foundation of China (No. 30370806).
文摘The 5＇-flanking proximal region of stress-induced gene encoding choline monooxygenase （CMO） was isolated by Adaptor-PCR and TAIL-PCR from halophyte Suaeda liaotungensis K. A total of 2,204 bp DNA sequence was obtained. The transcription start site, which is located at 128 bp upstream to the start ATG, was predicted by the TSSP-TCM program. The functional elements were analysed by PLACE program. The obtained SICMO gene promoter contains the basic elements： TATA-box, CAAT-box, and stress-induced elements, for example, salt responsive element （GAAAAA）, cold responsive elements （CANNTG）, ABA （Abscisic Acid） responsive elements （NAACAA）, water stress element （CGGTTG）, and WUN responsive elements （GTTAGGTTC）. Isolation and analysis of the promoter of the CMO gene from S. liaotungensis lays a foundation for characterising the stress-induced promoter elements, studying the relationship between the structure and function of the promoter, and investigating the molecular mechanism of CMO gene regulation.
