Search Results
throughout the province due to its high yield, good field performance, and strong adaptability. Fruit softening mainly results from cell wall degradation and the changes in cell wall composition, which are determined by a group of cell wall–modifying enzymes
Prestorage infiltration of `Golden Delicious' apples (Malus domestica Borkh.) with calcium (Ca) retarded texture changes during storage at 0C and inhibited ethylene production of the fruit at 20C. Infiltration of the fruit with the polyamines (PA) putrescine (PUT) or spermidine (SPD) also altered texture changes, but did not inhibit ethylene production. When the fruit were treated with Ca first and then with PA, cell wall-hound Ca concentrations increased 4-fold, but PA levels in the cell wall increased only slightly. When the fruit were treated with PA first and then with Ca, PA levels in the cell wall increased 3-fold, but Ca concentration increased only 2-fold. These results indicate that Ca and PA may he competing for the same binding sites in the cell wall and that the improvement of fruit quality during storage by these cations could involve strengthening of the cell wall.
., 2011 ). Loosening of the cell wall to increase plasticity and the presence of adequate turgor pressure are key factors that facilitate cell expansion ( Cosgrove et al., 2002 ). Cell wall extensibility is affected by multiple enzymes, including expansins
. The parameters examined included ethylene production, levels of antioxidant enzymes and lipoxygenase, transcript levels of cell wall hydrolases and manganese–superoxide dismutase (Mn-SOD), total RNA, and protein expression. We provide evidence, here
the up-regulation of cell wall hydrolytic enzymes, such as endo-1,4-glucanase (cellulase), polygalacturonase (PG), pectate lyase (PL), and pectin methylesterase (PME), resulting in dissolution of the middle lamella that connects the two adjacent cells
investigated here must be accounted for within these two tissues. Mechanically relevant properties of soft tissues include the amount of applied stress, the properties of cell walls, and of the middle lamellae. Also involved are cell turgor, the permeability of
rotation between the longitudinal axis of the spot or cell and the stem/stylar scar axis of the fruit. Cell size and cell wall thickness of cells within and outside the pale spots were quantified by image analysis using paired observations on ‘Regina’ sweet
. This phase is associated with various morphological and biochemical changes within the AZ cells, including alterations in cell wall composition, a process mediated by a set of enzymes such as polygalacturonases, cellulases, xyloglucan endo
supporting flux into other carbon sinks (e.g., cell wall formation or protein formation) within the tissue. Results and Discussion The respiration rate in the tip (Section 1) of asparagus spears was ≈40% to 50% higher than the section immediately basal to it
Many studies of apple (Malus ×domestica Borkh.) softening have been done using cultivars that eventually become mealy. We wanted to determine whether observations in these studies would be seen in a cultivar that maintains its crispness. In this paper, we compared the texture, ultrastructure, and some physiological parameters of Honeycrisp, an apple cultivar introduced in 1991 by the Minnesota Agricultural Experiment Station, with its parents and Delicious. Sensory evaluations and instrumental texture measurements showed that `Honeycrisp' maintained a crisp texture from harvest through 6 months of cold storage, whereas its parents, `Macoun' and `Honeygold', softened over the same time period. Turgor potential, cell wall composition, and ultrastructural comparisons of the fruit were made. Cell turgor potentials of `Honeycrisp' and `Delicious' were similar and greater than those of `Macoun' and `Honeygold', and clearly correlated with firmness. There were no differences in cell wall neutral sugar composition, except for arabinose, which was not highly correlated with crispness. `Honeycrisp' fruit maintained cell wall integrity after 6 months of storage, while cell walls of `Macoun' and `Honeygold' deteriorated. These data show that it is important to compare more than one cultivar when studying crispness. Honeycrisp is a cultivar that maintains its crispness through long storage without controlled atmosphere conditions. After 6 months of storage, this crispness can be attributed to a maintenance of high turgor potential and cell wall integrity.