Further Experiments on the β-Amylase-Containing Lysosomes of Wheat Aleurone Cells

1975 ◽  
Vol 2 (1) ◽  
pp. 41 ◽  
Author(s):  
RA Gibson ◽  
LG Paleg
Keyword(s):  
Cell Wall ◽  
Gibberellic Acid ◽  
Acid Treatment ◽  
Chelating Agents ◽  
Specific Binding ◽  
Hydrolytic Enzymes ◽  
Supernatant Fraction ◽  
Acid Gas ◽  
Aleurone Cells ◽  
Aleurone Tissue

The presence of hydrolytic enzymes in sedimentable fractions (lysosomes) of homogenized gibberellic acid (GAS)-treated wheat aleurone tissue has been further examined. Non-specific binding of free α-amylase (EC 3.2.1.1) to any organelle did not occur when added before homogenization to aleurone tissue either treated with GA3 or untreated, nor when amylose was added to GA3-treated tissue. The distribution of sedimentable α-amylase between different centrifugal fractions could be controlled, however, by varying the concentrations of calcium or chelating agents in the grinding medium. The concentration of GA*3 applied to aleurone tissue altered neither the percentage nor the distribution of α-amylase recovered in the various particulate fractions. Of the α-amylase appearing in the supernatant fraction, a large proportion appears to be located in the cell wall and is inactivated by acid treatment prior to homogenization, confirming previous reports. Tissue treated in this way yields more than 80% of the recoverable enzyme in sedimentable fractions.

DORMANCY STUDIES IN SEED OF AVENA FATUA: 5. ON THE RESPONSE OF ALEURONE CELLS TO GIBBERELLIC ACID

1966 ◽  
Vol 44 (1) ◽  
pp. 19-32 ◽  
Author(s):  
J. M. Naylor
Keyword(s):  
Amino Acids ◽  
Gibberellic Acid ◽  
Avena Fatua ◽  
Wild Oats ◽  
Aleurone Cells ◽  
Aleurone Tissue ◽  
Primary Action

The synthesis of α-amylase by excised aleurone tissue can be induced by supplying either gibberellic acid (GA) or a mixture of amino acids and sucrose. Aleurone cells form RNA within 4 hours after the imbibition of water or a solution of GA. Synthesis of RNA is essential for the subsequent production of the enzyme. The primary action of GA leading to production of the enzyme begins at about the same time as the first synthesis of RNA. Loss of dormancy during after-ripening involves changes in the response of aleurone cells to gibberellin. Aleurone cells of a non-dormant domestic oat variety Torch exhibit a greater autonomy in the control of α-amylase synthesis than those of wild oats. The current hypothesis that GA acts by genetic derepression is discussed.

Immunohistochemical localization of alpha-amylase in barley aleurone cells

1976 ◽  
Vol 20 (1) ◽  
pp. 183-198
Author(s):  
R.L. Jones ◽  
R.F. Chen
Keyword(s):  
Cell Wall ◽  
Wall Layer ◽  
Immunohistochemical Localization ◽  
Alpha Amylase ◽  
Perinuclear Region ◽  
Nuclear Region ◽  
Aleurone Cells ◽  
Rabbit Igg ◽  
Barley Aleurone ◽  
Aleurone Tissue

Alpha-Amylase was localized in aleurone cells of barley using immunohistochemical methods. Anti-alpha-amylase antibody was produced by rabbits immunized with enzyme purified from malt diastase and Himalaya variety barley seeds. Immunoelectrophoresis showed that the antibodies to both antigens were immunologically similar, therefore, they were used interchangeably in the localization of alpha-amylase. Fluorescence of 8–10 mum sections of freeze-substituted and paraffin embedded, gibberellic acid (GA)-treated aleurone tissue incubated with rabbit anti-alpha-amylase IgG and rhodamine-conjugated goat-anti-rabbit IgG is localized in the cytoplasm, the nuclear region and the innermost portion of the cell wall. Cytoplasmic immunofluorescence is not associated with a specific organelle but rather is diffusely distributed. The fluorescence of the nuclear region, however, is intense and in thinner (4-5 mum) sections is associated not with the nucleoplasm but with the nuclear envelope and perinuclear region of the cytoplasm. Fluorescence of the cell wall is confined to the inner boundary of the wall corresponding to the resistant wall layer. The immunofluorescent properties of non-GA-treated cells are quantitatively different; fluorescence of these sections is low and diffuse and is particularly reduced in the nuclear region. Electron microscopy shows that GA-treatment results in the proliferation of endoplasmic reticulum (ER) in the perinuclear region of the cell. We suggest that the alpha-amylase localized by immunofluorescence in the perinuclear region of the cell is localized in this ER produced in response to GA treatment. Immunohistochemical localization of alpha-amylase in cells zonated by centrifugation also suggests that the enzyme is intimately associated with the perinuclear area.

scholarly journals The Influence of Flower Head Order and Gibberellic Acid Treatment on the Hydroxycinnamic Acid and Luteolin Derivatives Content in Globe Artichoke Cultivars

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1813
Author(s):  
María José Giménez ◽  
Marina Giménez-Berenguer ◽  
María Emma García-Pastor ◽  
Joaquín Parra ◽  
Pedro Javier Zapata ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Acid Content ◽  
Acid Treatment ◽  
Bioactive Compound ◽  
Hydroxycinnamic Acid ◽  
Flower Head ◽  
Globe Artichoke ◽  
Rp Hplc ◽  
Head Weight ◽  
Gibberellic Acid Treatment

Flower head orders and the use of GA3 (gibberellic acid) treatment could be two influencing factors determining the bioactive compound levels in artichoke, but little to no information is available about their effects. In this study, we have therefore evaluated the influence of these factors on the hydroxycinnamic acid and luteolin derivative levels in three categories of artichoke: Seed-propagated open-pollinated cultivars; vegetatively propagated cultivars; and seed-propagated hybrids. The hydroxycinnamic acids and luteolin derivatives were quantified by RP-HPLC-DAD. The average flower head weight was the lowest in tertiary heads and GA3-treated artichokes, followed by secondary and main heads. Moreover, the hydroxycinnamic acid and luteolin derivatives levels were significantly higher in tertiary heads than in secondary or main heads. In addition, the GA3 treatment significantly reduced the hydroxycinnamic acid content and, in contrast, improved luteolin derivatives levels. These effects depended on the flower head order and cultivar. Knowledge of the effects of flower head order and GA3 treatment is therefore key in order to achieve the greatest health-benefits from artichoke consumption.

Changes in the cell wall components produced by exogenous abscisic acid treatment in strawberry fruit

Cellulose ◽  
2021 ◽  
Author(s):  
Ricardo I. Castro ◽  
Ana Gonzalez-Feliu ◽  
Felipe Valenzuela-Riffo ◽  
Carolina Parra-Palma ◽  
Luis Morales-Quintana
Keyword(s):  
Cell Wall ◽  
Abscisic Acid ◽  
Acid Treatment ◽  
Strawberry Fruit ◽  
Cell Wall Components ◽  
Wall Components

scholarly journals Regulation of Cell Wall Synthesis in Avena Stem Segments by Gibberellic Acid

1975 ◽  
Vol 55 (6) ◽  
pp. 1043-1047 ◽  
Author(s):  
Michael J. Montague ◽  
Hiroshi Ikuma
Keyword(s):  
Cell Wall ◽  
Gibberellic Acid ◽  
Cell Wall Synthesis ◽  
Stem Segments

scholarly journals The Role of Arabinogalactan Type II Degradation in Plant-Microbe Interactions

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria Guadalupe Villa-Rivera ◽  
Horacio Cano-Camacho ◽  
Everardo López-Romero ◽  
María Guadalupe Zavala-Páramo
Keyword(s):  
Cell Wall ◽  
Plant Defense ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Degradation Products ◽  
Hydrolytic Enzymes ◽  
Pathogenic Fungi ◽  
Plant Interactions ◽  
Root Tips ◽  
Microbe Interactions

Arabinogalactans (AGs) are structural polysaccharides of the plant cell wall. A small proportion of the AGs are associated with hemicellulose and pectin. Furthermore, AGs are associated with proteins forming the so-called arabinogalactan proteins (AGPs), which can be found in the plant cell wall or attached through a glycosylphosphatidylinositol (GPI) anchor to the plasma membrane. AGPs are a family of highly glycosylated proteins grouped with cell wall proteins rich in hydroxyproline. These glycoproteins have important and diverse functions in plants, such as growth, cellular differentiation, signaling, and microbe-plant interactions, and several reports suggest that carbohydrate components are crucial for AGP functions. In beneficial plant-microbe interactions, AGPs attract symbiotic species of fungi or bacteria, promote the development of infectious structures and the colonization of root tips, and furthermore, these interactions can activate plant defense mechanisms. On the other hand, plants secrete and accumulate AGPs at infection sites, creating cross-links with pectin. As part of the plant cell wall degradation machinery, beneficial and pathogenic fungi and bacteria can produce the enzymes necessary for the complete depolymerization of AGs including endo-β-(1,3), β-(1,4) and β-(1,6)-galactanases, β-(1,3/1,6) galactanases, α-L-arabinofuranosidases, β-L-arabinopyranosidases, and β-D-glucuronidases. These hydrolytic enzymes are secreted during plant-pathogen interactions and could have implications for the function of AGPs. It has been proposed that AGPs could prevent infection by pathogenic microorganisms because their degradation products generated by hydrolytic enzymes of pathogens function as damage-associated molecular patterns (DAMPs) eliciting the plant defense response. In this review, we describe the structure and function of AGs and AGPs as components of the plant cell wall. Additionally, we describe the set of enzymes secreted by microorganisms to degrade AGs from AGPs and its possible implication for plant-microbe interactions.

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