Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, 510640, China.
Guangxi South Subtropical Agricultural Science Research Institute, Guangxi Academy of Agricultural Sciences, Longzhou 532415, China.
Plant Physiol Biochem. 2024 May;210:108621. doi: 10.1016/j.plaphy.2024.108621. Epub 2024 Apr 9.
To enhance the postharvest quality of avocado (Persea americana Mill.) fruit, this study investigates alterations in cell wall metabolism and reactive oxygen species (ROS) metabolism during near-freezing temperature (NFT) storage, and explores their impact on fruit softening. The fruit was stored at 25 °C, 5 °C, 2 °C, and NFT, respectively. NFT storage retarded firmness loss and chilling injury in comparison with 25 °C, 5 °C, and 2 °C. NFT storage delayed the decrease of ionic-soluble pectin (ISP) and cellulose (CLL) contents by suppressing cell wall degradation enzyme activities. Correlation analysis showed that cell wall degradation enzyme activities were positively correlated to rates of ethylene release and respiration. Moreover, NFT storage maintained higher levels of DPPH and ABTS scavenging abilities, activities of superoxide dismutase, peroxidase, and catalase, as well as ascorbate-glutathione cycle (ascorbic acid, glutathione, glutathione disulfide, ascorbate peroxidase, cycle-related enzymes), thereby inhibited the increase of ROS content, malondialdehyde content, and cell membrane permeability. Fruit firmness and chilling injury were correlated with the contents of hydrogen (HO), superoxide anion (O), ISP, and CLL. These results suggested that NFT could suppress fruit softening and chilling injury by inhibiting cell wall degradation through delaying respiration and ethylene production and suppressing ROS production via activation of antioxidant systems, thereby maintaining quality and prolonged storage life during avocado fruit storage.
为了提高鳄梨（Persea americana Mill.）果实的采后品质，本研究调查了近冰点（NFT）贮藏过程中细胞壁代谢和活性氧（ROS）代谢的变化及其对果实软化的影响。果实分别在 25°C、5°C、2°C 和 NFT 下贮藏。与 25°C、5°C 和 2°C 相比，NFT 贮藏能延缓果实硬度下降和冷害。NFT 贮藏通过抑制细胞壁降解酶活性，延缓离子可溶果胶（ISP）和纤维素（CLL）含量的下降。相关分析表明，细胞壁降解酶活性与乙烯释放和呼吸速率呈正相关。此外，NFT 贮藏保持较高的 DPPH 和 ABTS 清除能力、超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性以及抗坏血酸-谷胱甘肽循环（抗坏血酸、谷胱甘肽、谷胱甘肽二硫化物、抗坏血酸过氧化物酶、与循环相关的酶），从而抑制 ROS 含量、丙二醛含量和细胞膜通透性的增加。果实硬度和冷害与 H （HO）、超氧阴离子（O）、ISP 和 CLL 的含量有关。这些结果表明，NFT 通过抑制呼吸和乙烯生成来抑制细胞壁降解，从而抑制果实软化和冷害，通过激活抗氧化系统抑制 ROS 生成，从而在鳄梨果实贮藏过程中保持品质和延长贮藏寿命。
