Related Experiment Video
Updated: Jun 27, 2026

Staining the Cytoplasmic Ca2+ with Fluo-4/AM in Apple Pulp
Published on: November 6, 2021
Physiological Responses of Apple to Nitrogen Fertilization Regimes: Roles of Calcium Metabolism in Fruit Quality and
Yue Xing1,2, Zhanling Zhu2, Ge Tian2,3
1College of Life Sciences, Zaozhuang University, Zaozhuang 277160, China.
Abstract:
Excessive or improper nitrogen (N) fertilization can disrupt calcium (Ca) nutrition in apple trees and induce Ca-related physiological disorders, yet its effects on Ca availability and partitioning remain unclear. This study evaluated the impact of different N fertilization regimes on soil Ca availability, Ca partitioning, and Ca bioavailability in fruit tissues of 10-year-old 'Fuji' apple trees, using Ca fractionation analysis combined with multi-criteria decision-making (TOPSIS). High N applied as a single dose (H1) significantly reduced soil water-soluble and exchangeable Ca, while increasing Ca oxalate (CaOx) accumulation in fruit pedicels, particularly at maturity. Although total CaOx in fruit flesh decreased, its relative proportion increased, indicating enhanced Ca sequestration. In contrast, split application of moderate N (M3) maintained more stable soil Ca availability, reduced CaOx accumulation, and improved Ca allocation to fruit tissues. Integrated evaluation ranked treatments as M3 > M1 > H3 > H1. Overall, moderate and split N fertilization reduced Ca sequestration into CaOx, enhanced Ca availability, and improved Ca distribution in fruit tissues, providing a physiological basis for optimizing N management to mitigate Ca-related disorders and improve fruit quality.
Related Concept Videos
Key Elements for Plant Nutrition
The Roles of Bacteria and Fungi in Plant Nutrition
Overview of Metabolism
Plant Metabolism
Sunlight, the primary source of energy in plants, is first absorbed by the chlorophyll pigments present in their leaves. Plants then use this energy to carry out photosynthesis, where water is oxidized into oxygen and carbon dioxide...
Adaptations that Reduce Water Loss
Fruit Development, Structure, and Function
Responses to Salt Stress
