Origin of nitrogen accumulated in the tulip roots in winter season

Ohyama, Takuji; Obata, Atsuko; Ikarashi, Taro

doi:10.1080/00380768.1988.10416478

Cited by 5 publications

(2 citation statements)

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“…The roots grow rapidly from the basal plate of bulbs after planting, and they accumulate a large amount of nitrogen (up to 9% based on dry weight) during the winter season Ikarashi 1967, 1968). It was found that the tulip roots absorb both ammonium and nitrate and they accumulate the nitrogen mainly in the form of glutamine under cold conditions (Kitajima et al, 1991;Komiyama et al, 2003;Ohyama et al, 1985bOhyama et al, , 1988dOhyama, 1991). The accumulated nitrogen in the roots supplements bulb storage nitrogen and is efficiently used for rapid shoot growth in early spring (Ohyama et al, 1988a;Ohyama, 1991).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Alpha-Amylase in Bulb Scales of Tulip (Tulipa Gesneriana L.)

Komiyama¹,

Murayama²,

Murai³

et al. 2005

Acta Hortic.

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We conducted biochemical and molecular analysis of tulip amylase. Enzyme extract was obtained from the scales of tulip bulbs after cold treatment for forcing cultivation, and some characteristics of the amylase were investigated. The amylase activity was measured by iodine-starch method. The degradation of soluble starch produced a series of maltooligosaccharides with different sizes. This indicates that the amylase in tulip bulb scale is endotype α α α α-amylase. The optimum pH for amylase activity was about 5.6. The enzyme activity was stable at neutral and alkaline pH (pH 5-10) at 4°C for 24h, but the activity remarkably decreased in acidic pH (pH<4.5). The α α α α-amylase requires Ca 2+ for its activity and stability. The optimum temperature for 5 min incubation was about 75°C in the presence of Ca 2+. The addition of 2 mM or 20 mM of Cu 2+ , Hg 2+ and Zn 2+ inhibited the amylase activity, but Ca 2+ , Mg 2+ , Fe 2+ , Co 2+ and Ni 2+ did not affect. A cDNA of α α α α-amylase was obtained by RT-PCR method using the primer designed from the database of the amino acid and DNA sequences of amylases in higher plants. The deduced amino acid sequence of the α α α α-amylase from tulip bulb scales has high similarity (identity 60%) to those of the rice and maize.

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Section: Introductionmentioning

confidence: 99%

Characteristics of Alpha-Amylase in Bulb Scales of Tulip (Tulipa Gesneriana L.)

Komiyama¹,

Murayama²,

Murai³

et al. 2005

Acta Hortic.

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“…was not detected in the --N treatment. Ohyama et al (1988b) previously reported that about 65% of total amino acids in tulip roots with N supply was present in the form of glutamine, which 4-methyleneglutamine was the predominant amino acid in roots of tulip cultivated under --N treatment during winter.…”

Section: N and Free Amino Acid Contentsmentioning

confidence: 99%