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Brian E Ellis - One of the best experts on this subject based on the ideXlab platform.

  • enzymology of udp glucose sinapic acid glucosyltransferase from Brassica Napus
    Phytochemistry, 1998
    Co-Authors: Shawn X. Wang, Brian E Ellis
    Abstract:

    UDP-glucose:sinapic acid glucosyltransferase (SGT; EC 2.4.1.120) was purified from 60-h-old seedlings of Brassica Napus. The purified SGT appears to be a cytosolic monomeric polypeptide with a Mr of 42 kDa and a pI of 5. Kinetic analysis suggested that the catalytic mechanism used by SGT best fits a ‘‘random bi–bi’’ model, with a Km (UDP-glucose) of 2.4 mM and Km (sinapic acid) of 0.16 mM. SGT also catalyzes the reverse reaction in vitro, using UDP and sinapoylglucose to form UDP-glucose. No cofactors are required for enzyme activity, but reducing agents and glycerol are required to stabilize the activity. The enzyme is strongly inhibited by p-OH-mercuribenzoic acid, UDP, TDP, Zn++, Cu++ and Hg++.

  • enzymology of udp glucose sinapic acid glucosyltransferase from Brassica Napus
    Phytochemistry, 1998
    Co-Authors: Shawn X. Wang, Brian E Ellis
    Abstract:

    UDP-glucose:sinapic acid glucosyltransferase (SGT; EC 2.4.1.120) was purified from 60-h-old seedlings of Brassica Napus. The purified SGT appears to be a cytosolic monomeric polypeptide with a Mr of 42 kDa and a pI of 5. Kinetic analysis suggested that the catalytic mechanism used by SGT best fits a ‘‘random bi–bi’’ model, with a Km (UDP-glucose) of 2.4 mM and Km (sinapic acid) of 0.16 mM. SGT also catalyzes the reverse reaction in vitro, using UDP and sinapoylglucose to form UDP-glucose. No cofactors are required for enzyme activity, but reducing agents and glycerol are required to stabilize the activity. The enzyme is strongly inhibited by p-OH-mercuribenzoic acid, UDP, TDP, Zn++, Cu++ and Hg++.

Shawn X. Wang - One of the best experts on this subject based on the ideXlab platform.

  • enzymology of udp glucose sinapic acid glucosyltransferase from Brassica Napus
    Phytochemistry, 1998
    Co-Authors: Shawn X. Wang, Brian E Ellis
    Abstract:

    UDP-glucose:sinapic acid glucosyltransferase (SGT; EC 2.4.1.120) was purified from 60-h-old seedlings of Brassica Napus. The purified SGT appears to be a cytosolic monomeric polypeptide with a Mr of 42 kDa and a pI of 5. Kinetic analysis suggested that the catalytic mechanism used by SGT best fits a ‘‘random bi–bi’’ model, with a Km (UDP-glucose) of 2.4 mM and Km (sinapic acid) of 0.16 mM. SGT also catalyzes the reverse reaction in vitro, using UDP and sinapoylglucose to form UDP-glucose. No cofactors are required for enzyme activity, but reducing agents and glycerol are required to stabilize the activity. The enzyme is strongly inhibited by p-OH-mercuribenzoic acid, UDP, TDP, Zn++, Cu++ and Hg++.

  • enzymology of udp glucose sinapic acid glucosyltransferase from Brassica Napus
    Phytochemistry, 1998
    Co-Authors: Shawn X. Wang, Brian E Ellis
    Abstract:

    UDP-glucose:sinapic acid glucosyltransferase (SGT; EC 2.4.1.120) was purified from 60-h-old seedlings of Brassica Napus. The purified SGT appears to be a cytosolic monomeric polypeptide with a Mr of 42 kDa and a pI of 5. Kinetic analysis suggested that the catalytic mechanism used by SGT best fits a ‘‘random bi–bi’’ model, with a Km (UDP-glucose) of 2.4 mM and Km (sinapic acid) of 0.16 mM. SGT also catalyzes the reverse reaction in vitro, using UDP and sinapoylglucose to form UDP-glucose. No cofactors are required for enzyme activity, but reducing agents and glycerol are required to stabilize the activity. The enzyme is strongly inhibited by p-OH-mercuribenzoic acid, UDP, TDP, Zn++, Cu++ and Hg++.

Mikael Johansson - One of the best experts on this subject based on the ideXlab platform.

  • different copies of sensitivity to red light reduced 1 show strong subfunctionalization in Brassica Napus
    BMC Plant Biology, 2019
    Co-Authors: Sarah V Schiessl, Natalie Williams, Pascal Specht, Dorothee Staiger, Mikael Johansson
    Abstract:

    Correct timing of flowering is critical for plants to produce enough viable offspring. In Arabidopsis thaliana (Arabidopsis), flowering time is regulated by an intricate network of molecular signaling pathways. Arabidopsis srr1–1 mutants lacking SENSITIVITY TO RED LIGHT REDUCED 1 (SRR1) expression flower early, particularly under short day (SD) conditions (1). SRR1 ensures that plants do not flower prematurely in such non-inductive conditions by controlling repression of the key florigen FT. Here, we have examined the role of SRR1 in the closely related crop species Brassica Napus. Arabidopsis SRR1 has five homologs in Brassica Napus. They can be divided into two groups, where the A02 and C02 copies show high similarity to AtSRR1 on the protein level. The other group, including the A03, A10 and C09 copies all carry a larger deletion in the amino acid sequence. Three of the homologs are expressed at detectable levels: A02, C02 and C09. Notably, the gene copies show a differential expression pattern between spring and winter type accessions of B. Napus. When the three expressed gene copies were introduced into the srr1–1 background, only A02 and C02 were able to complement the srr1–1 early flowering phenotype, while C09 could not. Transcriptional analysis of known SRR1 targets in Bna.SRR1-transformed lines showed that CYCLING DOF FACTOR 1 (CDF1) expression is key for flowering time control via SRR1. We observed subfunctionalization of the B. Napus SRR1 gene copies, with differential expression between early and late flowering accessions of some Bna.SRR1 copies. This suggests involvement of Bna.SRR1 in regulation of seasonal flowering in B. Napus. The C09 gene copy was unable to complement srr1–1 plants, but is highly expressed in B. Napus, suggesting specialization of a particular function. Furthermore, the C09 protein carries a deletion which may pinpoint a key region of the SRR1 protein potentially important for its molecular function. This is important evidence of functional domain annotation in the highly conserved but unique SRR1 amino acid sequence.

Sarah V Schiessl - One of the best experts on this subject based on the ideXlab platform.

  • different copies of sensitivity to red light reduced 1 show strong subfunctionalization in Brassica Napus
    BMC Plant Biology, 2019
    Co-Authors: Sarah V Schiessl, Natalie Williams, Pascal Specht, Dorothee Staiger, Mikael Johansson
    Abstract:

    Correct timing of flowering is critical for plants to produce enough viable offspring. In Arabidopsis thaliana (Arabidopsis), flowering time is regulated by an intricate network of molecular signaling pathways. Arabidopsis srr1–1 mutants lacking SENSITIVITY TO RED LIGHT REDUCED 1 (SRR1) expression flower early, particularly under short day (SD) conditions (1). SRR1 ensures that plants do not flower prematurely in such non-inductive conditions by controlling repression of the key florigen FT. Here, we have examined the role of SRR1 in the closely related crop species Brassica Napus. Arabidopsis SRR1 has five homologs in Brassica Napus. They can be divided into two groups, where the A02 and C02 copies show high similarity to AtSRR1 on the protein level. The other group, including the A03, A10 and C09 copies all carry a larger deletion in the amino acid sequence. Three of the homologs are expressed at detectable levels: A02, C02 and C09. Notably, the gene copies show a differential expression pattern between spring and winter type accessions of B. Napus. When the three expressed gene copies were introduced into the srr1–1 background, only A02 and C02 were able to complement the srr1–1 early flowering phenotype, while C09 could not. Transcriptional analysis of known SRR1 targets in Bna.SRR1-transformed lines showed that CYCLING DOF FACTOR 1 (CDF1) expression is key for flowering time control via SRR1. We observed subfunctionalization of the B. Napus SRR1 gene copies, with differential expression between early and late flowering accessions of some Bna.SRR1 copies. This suggests involvement of Bna.SRR1 in regulation of seasonal flowering in B. Napus. The C09 gene copy was unable to complement srr1–1 plants, but is highly expressed in B. Napus, suggesting specialization of a particular function. Furthermore, the C09 protein carries a deletion which may pinpoint a key region of the SRR1 protein potentially important for its molecular function. This is important evidence of functional domain annotation in the highly conserved but unique SRR1 amino acid sequence.

Weijun Zhou - One of the best experts on this subject based on the ideXlab platform.

  • calcium invigorates the cadmium stressed Brassica Napus l plants by strengthening their photosynthetic system
    Environmental Science and Pollution Research, 2011
    Co-Authors: Guanglong Wan, Muhammad Naeem, Ullah Najeeb, Ghulam Jilani, Weijun Zhou
    Abstract:

    Introduction Cadmium (Cd) in plants interrupts numerous metabolic processes and reduces the water and nutrient uptake that cause chlorosis, growth retardation, and ultimately plant death. Response of Brassica Napus L. to calcium (Ca) enrichment in growth medium for reducing Cd toxicity stress by strengthening the photosynthesis organelles and their functionality was explored in this study.

  • 5 aminolevulinic acid ameliorates salinity induced metabolic water related and biochemical changes in Brassica Napus l
    Acta Physiologiae Plantarum, 2011
    Co-Authors: Muhammad Naeem, D F Ming, Muhammad Rasheed, Yasutomo Takeuchi, Koichi Yoneyama, Weijun Zhou
    Abstract:

    A number of studies have established that plant growth and development in oilseed rape (Brassica Napus L.) are hampered by salinity stress. Nowadays, researchers have focused on the use of plant growth regulators to increase plant tolerance against salinity. An experiment was performed to evaluate the effects of 5-aminolevulinic acid (ALA, 30 mg l−1) on Brassica Napus L. (cv. ‘ZS 758’) plants under NaCl (100, 200 mM) salinity. Data presented here were recorded on two different leaf positions (first and third) to have a better understanding of the ameliorative role of ALA on NaCl-stressed oilseed rape plants. Results have shown that increasing salinity imposed negative impact on relative growth rate (root and shoot) and leaf water relations (osmotic potential and relative water content), whereas enhanced the level of relative conductivity, malondialdehyde (MDA) content, osmolytes (soluble sugar, soluble protein, free amino acid and proline) concentration, reactive oxygen species (ROS), and enzymatic (ascorbate peroxidase, guaiacol peroxidase, catalase and superoxide dismutase) and non-enzymatic (reduced glutathione and ascorbate) antioxidants activity in two different leaf position samples. Foliar application of ALA improved relative growth rate (root and shoot) and leaf water relations (osmotic potential and relative water content), and also triggered the further accumulation of osmolytes (soluble sugar, soluble protein, free amino acid and proline) as well as enzymatic (ascorbate peroxidase, guaiacol peroxidase, catalase and superoxide dismutase) and non-enzymatic (reduced glutathione and ascorbate) antioxidants activity in both leaf samples, whereas decreased the membrane permeability, MDA content and ROS production. Our results also indicate that osmolytes are preferentially accumulated in younger tissues.

  • cold pretreatment enhances microspore embryogenesis in oilseed rape Brassica Napus l
    Plant Growth Regulation, 2004
    Co-Authors: P Hagberg, Weijun Zhou
    Abstract:

    Stress is an essential component during embryogenesis induction in microspore culture. Cold pretreatment has been used in cereal microspore culture but very seldom attempted in Brassica microspore culture. The effect of cold pretreatment of flower buds subjected to a liquid medium on microspore embryogenesis was investigated in spring and winter Brassica Napus, as well as in B. rapa and B. oleracea. Cold pretreatment significantly enhanced microspore embryogenesis (by 1–7 fold) compared to commonly used microspore culture protocol in B. Napus, while it was less effective in B. rapa or even negative in B. oleracea. The appropriate duration of cold pretreatment was found to be 2–4 days, which stimulated the best microspore embryogenesis. Cold pretreatment was also able to promote embryo development including the improvement of embryo quality and acceleration of embryogenesis. When incorporating with medium refreshing, cold pretreatment could initiate the most microspore embryogenesis than any other treatment used. With further improvement cold pretreatment method may have a positive potential in Brassica breeding programmes.