Quantifying cutin and wax deposition in developing apple fruit
Final Report Abstract
The pattern of cuticle deposition plays an important role in managing the buildup of strain in fruit cuticles. Growth of the fruit exposes the cuticle to the risk of failure by increasing the strain the cuticle. Strain, in turn, is the primary trigger for numerous fruit-surface disorders in many fruit crop species. Earlier study (Khanal et al., 2014) reported higher strain in the outer layers of the cuticle than in the inner layers. Later, Knoche et al. (2018) reported that the outer layer of the cuticle is more susceptible to microcracking than the inner layer. Both studies suggested that the cuticle is growing continuously in the inner side when the fruit is developing, but direct experimental evidence was lacking. In this study, we showed that externally applied C oleic acid was incorporated in the cutin in the inner side of the cuticle of the apple fruit surface. This provides direct evidence for the continuous buildup of the cuticle from its inner side. Our finding explains also the mechanistic basis of the radial gradient in strain reported earlier and the higher susceptibility of the outer layer of the cuticle to microcracking. We also found that the application of oleic acid on the fruit surface increases the deposition of the cuticle (more cuticle mass per unit fruit surface area). This increase is gravimetrically detectable. Enhanced deposition of the cuticle on the inner side could help to minimize formation and radial extension of deep microcracks thereby minimizing the development of surface blemishes. The findings of this study may have significant practical implications for commercial production to improve the quality of apple fruit. Follow up research is needed.
Publications
- 2021. Direct evidence for a radial gradient in age of the apple fruit cuticle. Frontiers in Plant Science
Si Y, Khanal BP, Schlüter OK, Knoche M
(See online at https://doi.org/10.3389/fpls.2021.730837) - Cutin Synthesis in Developing, Field- Grown Apple Fruit Examined by External Feeding of Labelled Precursors. Plants, 10, 497
Si Y, Khanal BP, Sauheitl L, Knoche M
(See online at https://doi.org/10.3390/plants10030497) - Factors affecting cuticle synthesis in apple fruit identified under field conditions. Scientia Horticulturae, 290, 110512
Si Y, Khanal BP, Knoche M
(See online at https://doi.org/10.1016/j.scienta.2021.110512)
