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Protective Effect of External Ca2+ on Elongation and the Intracellular Concentration of K+ in Intact Mung Bean Roots under High NaCl Stress 总被引:2,自引:0,他引:2
Nakamura Yoshiyuki; Tanaka Karo; Ohta Eiji; Sakata Makoto 《Plant & cell physiology》1990,31(6):815-821
The effects of Ca2+ in the external medium on intact mung beanroots under high NaCl stress were investigated. With increasingexternal concentrations of NaCl, mung bean roots showed suppressionof elongation and a decrease in the intracellular concentrationof K+. Addition of Ca2+ to the external medium alleviated theinhibition of root elongation under the high NaCl stress andmaintained a high intracellular concentration of K+ in the elongatingregion of the roots. This counter effect of Ca2+ against theNaCl stress on roots was correlated with the ratio of [Ca2+]/[Na+]2in the external medium. A value above 5.0 ? 104 mM1resulted in almost complete recovery of root elongation undervarious high concentrations of NaCl. Root elongation for 24h under NaCl stress was correlated with the extent to whichthe intracellular concentration of K+ was in excess of 10 mM.Maintenance of an adequate concentration of K+ in root cellsis essential for root elongation under salt stress. These findingsindicate that Ca2+ prevents the leakage of intracellular K+and thereby supports the elongation of roots under salt stress. (Received November 13, 1989; Accepted June 5, 1990) 相似文献
3.
Changes in Targeting Efficiencies of Proteins to Plant Microbodies Caused by Amino Acid Substitutions in the Carboxy-terminal Tripeptide 总被引:7,自引:0,他引:7
Hayashi Makoto; Aoki Masahiro; Kondo Maki; Nishimura Mikio 《Plant & cell physiology》1997,38(6):759-768
It has been demonstrated that the carboxyl terminus of microbodyenzymes functions as a targeting signal to microbodies in higherplants. We have examined an ability of 24 carboxy-terminal aminoacid sequences to facilitate the transport of a cytosolic passengerprotein, ß-glucuroni-dase, into microbodies in greencotyledonary cells of trans-genic Arabidopsis. Immunoelectronmicroscopic analysis revealed that carboxy-terminal tripeptidesequences of the form [C/A/S/P]-[K/R]-[I/L/M] function as amicrobody-targeting signal, although tripeptides with prolineat the first amino acid position and isoleucine at the carboxylterminus show weak targeting efficiencies. All known micro-bodyenzymes that are synthesized in a form similar in size to themature molecule, except catalase, contain one of these tripeptidesequences at their carboxyl terminus. (Received April 14, 1997; Accepted April 8, 1997) 相似文献
4.
From the root bark of Hovenia dulcis Thunb. and H. tommentella (Makino) Nakai (Rhamnaceae), three peptide alkaloids, frangulanine, hovenins-A and -B have been isolated. Hovenin-A has been shown to be des-N-methylfrangulanine (II). 相似文献
5.
Aerenchyma development in waterlogged Helianthus annuus, Lycopersicon esculentum, and Salix fragilis was studied. More than half of the root cortical tissue sometimes became an air cavity in willow roots which developed in water. There was no cortical aerenchyma in the terminal portion, but more advanced aerenchyma developed towards the base of the sunflower roots formed in water. Waterlogged sunflower and tomato plants developed lysigenous aerenchyma in the cortex of waterlogged stems within two days. 相似文献
6.
Brown Norway rat strain has been studied for mode of inheritance of its congenital deficiency in plasma high molecular weight (HMW)-kininogen and low molecular weight (LMW)-kininogen, and low plasma level of prekallikrein. We examined the genetics of the deficiency by performing a mixed breeding experiment between B/N-Katholiek (B/N-Ka, deficient) and B/N-Kitasato (B/N-Ki, normal) strains. Incidence of the deficiency was judged by the plasma level of HMW-kininogen. Plasma level of HMW-kininogen was around 50% of the normal level in all F1 generations of the hybrid between male B/N-Ka and female B/N-Ki (Exp. 1), and between female B/N-Ka and male B/N-Ki (Exp. 2). Incidence of deficiency (plasma HMW-kininogen level less than 5%) in Exp. 1 was 23.8% in male F2 and 20.0% in female F2 generations. By Exp. 2 also the incidence was 25.0% in male and 30.0% in female F2 generations. There was no significant difference of the incidence between the two experiments or sexes. These results indicate the inheritance of the kininogen-deficiency to be Mendelian autosomal recessive, the same as for the reported cases of human kininogen deficiency. Gel filtration study suggests that prekallikrein in the B/N-Ka plasma may be free form, while that in the B/N-Ki plasma may form complex with HMW-kininogen. 相似文献
7.
Induction and Secretion of Pathogenesis-Related Proteins by Salicylate or Plant Hormones in Tobacco Suspension Cultures 总被引:3,自引:0,他引:3
Pathogenesis-related proteins (PR proteins), that are inducedin tobacco leaves in hypersensitive response to infection withtobacco mosaic virus (TMV) or by treatment with chemicals, werefound to be also inducible in a dedifferentiated system, tobaccosuspension culture. Quantitative determination of these proteinsusing anti PR 1a IgG showed that their increase started at aboutthe end of cell growth period and that their production couldbe enhanced by the addition of potassium salicylate, Eosin Yellowishand plant hormones (GA3, IAA and 2,4-D). The production dependedon the concentration of the chemical inducer and the cell lineused. In BY-2 cell line, PR proteins amounted to 12 µgat day 5 and then increased exponentially with time, reaching280 µg or 70 µg per g fr wt of cells at day 9 withor without the addition of 25 µM potassium salicylate.More than 90% of the induced PR proteins was found in the mediumand less than 10% in the cells at day 9. Peroxidase activityin the medium was constant throughout the experiment althoughtotal activity in the flask increased with cell growth, indicatingthat PR proteins are actively secreted into the medium. (Received November 12, 1986; Accepted March 6, 1987) 相似文献
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Shigeo Koyasu Makoto Asada Akio Fukuda Yoshimi Okada 《Journal of molecular biology》1981,153(2):471-475
The mode of polymerization of two species of flagellins, flagellin A and flagellin B, in polar flagella of Caulobacter crescentus was examined. By immunological staining we found that 1 to 1.2 μm of the portion of the flagellar filament proximal to the cell was composed of flagellin B, whereas about 5 μm of the distal portion was composed of flagellin A. This result, together with the previous observation that a flagellin B-less mutant cannot form normal flagella but instead forms stubs in spite of their high level of flagellin A synthesis, indicates that flagellin B is very important for the formation of complete flagella and/or for the initiation of filament formation from the hook. 相似文献