Abstract:
:Amylase was found in high activity (193 international units per milligram protein) in the tap root of alfalfa (Medicago sativa L. cv. Sonora). The activity was separated by gel filtration chromatography into two fractions with molecular weights of 65,700 (heavy amylase) and 41,700 (light amylase). Activity staining of electrophoretic gels indicated the presence of one isozyme in the heavy amylase fraction and two in the light amylase fraction. Three amylase isozymes with electrophoretic mobilities identical to those in the heavy and the light amylase fractions were the only amylases identified in crude root preparations. Both heavy and light amylases hydrolyzed amylopectin, soluble starch, and amylose but did not hydrolyze pullulan or beta-limit dextrin. The ratio of viscosity change to reducing power production during starch hydrolysis was identical for both alfalfa amylase fractions and sweet potato beta-amylase, while that of bacterial alpha-amylase was considerably higher. The identification of maltose and beta-limit dextrin as hydrolytic end-products confirmed that these alfalfa root amylases are all beta-amylases.The pH optimum for both beta-amylase fractions was 6.0. Both light and heavy beta-amylases showed normal Michaelis-Menten kinetics, with soluble starch as substrate, and had respectively K(m) values of 5.9 and 6.8 milligrams starch per milliliter and V(max) of 640 and 130 international units per milligram protein. Arrhenius plots indicated that the energy of activation for the heavy beta-amylase remained relatively unchanged (12.7 to 13.0 kilocalories per mole) from 0 to 30 degrees C, whereas the energy of activation for the light amylase increased from 12.0 to about 28.0 kilocalories per mole at 8.7 degrees C as temperature was lowered. The light amylase was shown to be inhibited by maltose.
journal_name
Plant Physioljournal_title
Plant physiologyauthors
Doehlert DC,Duke SH,Anderson Ldoi
10.1104/pp.69.5.1096subject
Has Abstractpub_date
1982-05-01 00:00:00pages
1096-102issue
5eissn
0032-0889issn
1532-2548journal_volume
69pub_type
杂志文章相关文献
PLANT PHYSIOLOGY文献大全abstract::The isotope competition method with glucose-U-(14)C as a carbon source has been used to determine whether or not selected compounds contribute carbon to the biosynthesis of protein amino acids in cells derived from Paul's Scarlet Rose. Of 48 compounds tested, 15 contributed carbon to protein amino acids. The results s...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.42.7.941
更新日期:1967-07-01 00:00:00
abstract::Levels of the enzymes that produce wound response mediators have to be controlled tightly in unwounded tissues. The Arabidopsis (Arabidopsis thaliana) fatty acid oxygenation up-regulated8 (fou8) mutant catalyzes high rates of alpha -linolenic acid oxygenation and has higher than wild-type levels of the alpha -linoleni...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.109.150474
更新日期:2010-03-01 00:00:00
abstract::Arabidopsis (Arabidopsis thaliana) leaf development relies on subsequent phases of cell proliferation and cell expansion. During the proliferation phase, chloroplasts need to divide extensively, and during the transition from cell proliferation to expansion, they differentiate into photosynthetically active chloroplas...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.114.256180
更新日期:2015-03-01 00:00:00
abstract::Abscisic acid (ABA), auxins, cytokinins, gibberellic acid, alone or in combination were tested for their effects on short-term sucrose uptake in sugar beet (Beta vulgaris cv USH-20) roots. The effect of ABA on active sucrose uptake varied from no effect to the more generally observed 1.4-to 3.0-fold stimulation. A rac...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.74.4.951
更新日期:1984-04-01 00:00:00
abstract::The endoplasmic reticulum (ER) stress response is a signal transduction pathway activated by the perturbation of normal ER metabolism. We used the maize (Zea mays) floury-2 (fl2) mutant and soybean (Glycine max) suspension cultures treated with tunicamycin (Tm) to investigate the ER stress response as it relates to ph...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.126.1.267
更新日期:2001-05-01 00:00:00
abstract::The relationship between gravitropism and surface electrical potentials was studied using etiolated epicotyls of adzuki bean (Phaseolus angularis). Early downward curvature (or transient positive gravitropic response) was observed about 1 min after gravistimulation. The downward curvature was closely related to the sp...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.105.3.875
更新日期:1994-07-01 00:00:00
abstract::This study demonstrates germination-induced ultrastructural changes in wheat (Triticum aestivum L. cv Arthur) aleurone cells. Seeds imbided for 4 hours in water contained endoplasmic reticulum (ER) or ER-like membranes as vesicles or as short segments of membrane associated with the spherosomes on the periphery of ale...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.68.6.1319
更新日期:1981-12-01 00:00:00
abstract::Antibodies were raised against carrot (Daucus carota) cell wall beta-fructosidase that was either in a native configuration (this serum is called anti-betaF(1)) or chemically deglycosylated (anti-betaF(2)). The two antisera had completely different specificities when tested by immunoblotting. The anti-betaF(1) serum r...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.90.3.1182
更新日期:1989-07-01 00:00:00
abstract::Dual-conditional positive/negative selection markers are versatile genetic tools for manipulating genomes. Plastid genomes are relatively small and conserved DNA molecules that can be manipulated precisely by homologous recombination. High-yield expression of recombinant products and maternal inheritance of plastid-en...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.112.204107
更新日期:2012-12-01 00:00:00
abstract::Phosphoenolpyruvate carboxylase purified from leaves of maize (Zea mays, L.) is sensitive to the presence of urea. Exposure to 2.5 m urea for 30 min completely inactivates the enzyme, whereas for a concentration of 1.5 m urea, about 1 h is required. Malate appears to have no effect on inactivation by urea of phosphoen...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.100.3.1366
更新日期:1992-11-01 00:00:00
abstract::Experiments with lettuce seeds during the first hours of imbibition showed that oxygen is necessary to sustain high adenine nucleotide ratios and consequently, energy charge values are higher than 0.8 as is usually the case in normally metabolizing tissues.The energy charge value (0.2) of dry seeds soaked in aerated w...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.68.3.631
更新日期:1981-09-01 00:00:00
abstract::Reduction of Cu2+ by plasma membrane vesicles isolated from tomato (Lycopersicon esculentum Mill.) roots was investigated. Plants were grown in hydroponic culture with complete nutrition for 4 weeks or were deprived of Fe for the last 7 d. Plasma membrane vesicles were prepared by aqueous two-phase partitioning. Reduc...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.108.3.1093
更新日期:1995-07-01 00:00:00
abstract::In pea stem segments whose cuticle has been made permeable by abrading it, actinomycin D (ActD) and 80S ribosomal protein synthesis inhibitors such as cycloheximide (CHI) inhibit enhancement by indole 3-acetic acid (IAA) of the activity of the cell wall biosynthetic enzyme, glucan synthase I (GS). This supersedes earl...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.85.2.523
更新日期:1987-10-01 00:00:00
abstract::Cyanobacteria unable to fix atmospheric nitrogen have evolved sophisticated adaptations to survive to long periods of nitrogen starvation. These genetic programs are still largely unknown-as evidenced by the many proteins whose expression is regulated in response to nitrogen availability, but which belong to unknown o...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.20.00802
更新日期:2020-12-01 00:00:00
abstract::L-Galactono-1,4-lactone dehydrogenase (EC 1.3.2.3) catalyzes the last step in the main pathway of vitamin C (L-ascorbic acid) biosynthesis in higher plants. In this study, we first characterized the spatial and temporal expression of SlGalLDH in several organs of tomato (Solanum lycopersicum) plants in parallel with t...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.107.106500
更新日期:2007-12-01 00:00:00
abstract::Non-dormant and dormant seeds of Avena fatua metabolize (14)C-maltose in different ways: in non-dormant seeds, (14)C-maltose administered to the endosperm is readily converted to sucrose in the scutellum and translocated to the embryo; in dormant seeds, little sucrose is synthesized from (14)C-maltose, and maltose and...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.44.5.770
更新日期:1969-05-01 00:00:00
abstract::Cell-type-specific gene expression is essential to distinguish between the numerous cell types of multicellular organism. Therefore, cell-type-specific gene expression is tightly regulated and for most genes RNA transcription is the central point of control. Thus, transcriptional reporters are broadly used markers for...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.16.00213
更新日期:2016-06-01 00:00:00
abstract::The evolutionarily conserved YidC/Oxa1/Alb3 proteins are involved in the insertion of membrane proteins in all domains of life. In plant mitochondria, individual knockouts of OXA1a, OXA2a, and OXA2b are embryo-lethal. In contrast to other members of the protein family, OXA2a and OXA2b contain a tetratricopeptide repea...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.18.01286
更新日期:2019-02-01 00:00:00
abstract::The thermophilic blue-green alga Synechococcus lividus was grown at 55 and 38 C. Arrhenius plots of the transient reduction of cytochrome during actinic illumination with light that excited both pigment systems revealed breaks near 43 and 26 C for cells grown at 55 C. In cells grown at 38 C these breaks occurred near ...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.63.3.524
更新日期:1979-03-01 00:00:00
abstract::The requirements for activation of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) were investigated in leaves of Arabidopsis wild-type and a mutant incapable of light activating rubisco in vivo. Upon illumination with saturating light intensities, the activation state of rubisco increased 2-fold in the wild...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.80.3.655
更新日期:1986-03-01 00:00:00
abstract::Short exposure of the spores of Cheilanthes farinosa to low intensity red light promotes their germination, which is not reversed by a subsequent exposure to far red light. Germination is, however, inhibited by blue light administered before or after red light. Inhibition of germination by blue light is annulled by ex...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.51.2.306
更新日期:1973-02-01 00:00:00
abstract::L-myo-inositol 1-phosphate synthase (EC 5.5.1.4) from cyanobacterial (Spirulina platensis), algal (Euglena gracilis), and higher plant (Oryza sativa, Vigna radiata) sources was purified to electrophoretic homogeneity, biochemically characterized, and compared. Both chloroplastic and cytosolic forms of the enzyme were ...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.115.2.727
更新日期:1997-10-01 00:00:00
abstract::4,6-Dioxoheptanoic acid (DA), an inhibitor of 5-aminolevulinic acid (ALA) dehydratase (EC 4.3.1.24), causes ALA to accumulate at the expense of chlorophyll when applied to greening leaves of Hordeum vulgare L. var. Larker. Preincubating etiolated leaves with DA in darkness eliminates the lag phase in ALA accumulation ...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.67.6.1065
更新日期:1981-06-01 00:00:00
abstract::Sorghum (Sorghum bicolor L. Moench) accumulates the anthocyanin cyanidin 3-dimalonyl glucoside in etiolated mesocotyls in response to light. Inoculation with the nonpathogenic fungus Cochliobolus heterostrophus drastically reduced the light-induced accumulation of anthocyanin by repressing the transcription of the ant...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.116.3.979
更新日期:1998-03-01 00:00:00
abstract::Calcium affects the stability of cortical microtubules (MTs) in lysed protoplasts. This calmodulin (CaM)-mediated interaction may provide a mechanism that serves to integrate cellular behavior with MT function. To test the hypothesis that CaM associates with these MTs, monoclonal antibodies were produced against CaM, ...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.103.2.543
更新日期:1993-10-01 00:00:00
abstract::The F-box protein CORONATINE INSENSITIVE1 (COI1) plays a central role in jasmonate (JA) signaling and is required for all JA responses in Arabidopsis (Arabidopsis thaliana). To dissect JA signal transduction, we isolated the partially suppressing coi1 (psc1) mutant, which partially suppressed coi1 insensitivity to JA ...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.109.140202
更新日期:2009-11-01 00:00:00
abstract::Phosphoenolpyruvate partially inhibits the accumulation of Ca(2+) in isolated mung bean (Phaseolus aureus Roxb.) mitochondria. Succinate-supported Ca(2+) uptake is twice as sensitive to phosphoenolpyruvate inhibition as is NADH- or malate/pyruvate-supported Ca(2+) uptake. Pyruvate, atractylate, and ATP, but not ITP, r...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.59.2.126
更新日期:1977-02-01 00:00:00
abstract::Breeding crops with the quality of broad-spectrum disease resistance using genetic resources is one of the principal goals of crop improvement. However, the molecular mechanism of broad-spectrum resistance remains largely unknown. Here, we show that GH3-2, encoding an indole-3-acetic acid (IAA)-amido synthetase, media...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.110.163774
更新日期:2011-01-01 00:00:00
abstract::The labeling pattern of the sugar moieties of 1-kestose after in vivo pulse labeling with (14)CO(2) was not the same as that after in vitro labeling with (14)C-sucrose. The two fructosyl residues of 1-kestose had similar specific radioactivities after in vitro synthesis, but after in vivo radiolabeling the specific ra...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.96.1.251
更新日期:1991-05-01 00:00:00
abstract::Branched-chain amino acids (BCAAs) are synthesized in plants from branched-chain keto acids, but their metabolism is not completely understood. The interface of BCAA metabolism lies with branched-chain aminotransferases (BCAT) that catalyze both the last anabolic step and the first catabolic step. In this study, six B...
journal_title:Plant physiology
pub_type: 杂志文章
doi:10.1104/pp.110.154922
更新日期:2010-07-01 00:00:00