NMR characterization of hydration and thermal stress in tomato fruit cuticles

• Published in: Phytochemistry (Oxford) Vol. 69; no. 15; pp. 2689 - 2695
• Main Authors: Stark, Ruth E., Yan, Bin, Stanley-Fernandez, Suzanne M., Chen, Zhen-jia, Garbow, Joel R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.11.2008; Elsevier
• Subjects: abiotic stress; Biological and medical sciences; biopolymers; C-13 NMR; Carbon - chemistry; chemical constituents of plants; Chemical constitution; CPMAS; Cuticle; Fruit; Fruit - chemistry; Fruit - drug effects; Fruit - metabolism; fruits (plant anatomy); Fundamental and applied biological sciences. Psychology; heat stress; Hydration stress; Lycopersicon esculentum; Lycopersicon esculentum - chemistry; Lycopersicon esculentum - drug effects; Lycopersicon esculentum - metabolism; Magnetic Resonance Spectroscopy; Molecular dynamics; NMR; nuclear magnetic resonance spectroscopy; Plant cuticle; Plant physiology and development; plant stress; Polyester; polyesters; Polymers - chemistry; Solanaceae; Solanum lycopersicum var. lycopersicum; Solid-state NMR; spectral analysis; Spin relaxation; Stress, Physiological; Temperature; Temperature stress; Time Factors; Tomato; tomatoes; Water - pharmacology; water stress; Solid-state NMR; Polyester; Fruit; Temperature stress; Plant cuticle; CPMAS; Molecular dynamics; Cuticle; Tomato; Hydration stress; NMR; Spin relaxation; Lycopersicon esculentum; Solanaceae; C-13 NMR; Temperature; Characterization; Dicotyledones; Angiospermae; Chemical structure; Nuclear magnetic resonance imaging; Stress; Solid state; Vegetable crop; Plant origin; Spermatophyta
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2008.08.016

A comprehensive 13C NMR relaxation study of tomato fruit cuticle has been made to assess the impact of hydration and thermal stresses on motions at individual polymer sites that are expected to influence the functional integrity of this protective plant membrane. In its natural environment, the plant cuticle, which is composed of the biopolymer cutin and a mixture of surface and embedded cuticular waxes, experiences a wide variety of temperatures and hydration states. Consequently, a complete understanding of cuticular function requires study of its thermal and mechanical properties as a function of hydration. Herein, we report the results of a comprehensive 13C nuclear magnetic resonance (NMR) relaxation study of hydrated tomato fruit cuticle. Cross-polarization and direct-polarization experiments serve to measure the solid-like and liquid-like components, respectively, of hydrated cuticle. Localized, high-frequency motions are probed by T 1(C) spin relaxation measurements, whereas T 1ρ(H) and T 1ρ(C) experiments reflect low-frequency, lower amplitude polymer-chain motions. In addition, variable-temperature measurements of T 1(C) and T 1ρ(C) for dry tomato cuticles are used to evaluate the impact of temperature stress. Results of these experiments are interpreted in terms of changes occurring in individual polymer motions of the cutin/wax components of tomato cuticle and in the interaction of these components within intact cuticle, both of which are expected to influence the functional integrity of this protective plant covering.