Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Faculty of Biology, Av. Diagonal 643, E-08028, Barcelona, Spain; Research Institute of Nutrition and Food Safety, University of Barcelona, Faculty of Biology, Av. Diagonal 643, E-08028, Barcelona, Spain.
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Faculty of Biology, Av. Diagonal 643, E-08028, Barcelona, Spain; Research Institute of Nutrition and Food Safety, University of Barcelona, Faculty of Biology, Av. Diagonal 643, E-08028, Barcelona, Spain.
J Plant Physiol. 2020 Aug;251:153225. doi: 10.1016/j.jplph.2020.153225. Epub 2020 Jul 4.
Avocados (Persea americana Mill.) are climacteric fruits, the ripening of which during postharvest at room temperature is strongly ethylene dependent. However, the role of other phytohormones in the modulation of postharvest ripening of avocados is still poorly understood. The optimal ripening state of avocados is attained a few days after harvest depending on the genotype, growing region and initial maturity stage of the fruit, and cold temperature storage is commonly used to delay this process. Here, we hypothesized that the ripening of avocados at room temperature may be governed not only by ethylene, but also by other phytohormones. With this aim, we analyzed the hormonal profiling of avocados subjected to either 4 °C and 25 °C during 10 days of postharvest. A biphasic response was observed during postharvest ripening of avocados at room temperature. While ethylene alone appeared to govern fruit ripening during the first transfer from cold to room temperature, a complex hormonal interplay occurred during ripening of avocados leading to a progressive fruit softening at room temperatures. Aside from ethylene, auxin, gibberellins, jasmonates and ABA appeared to be involved in avocado fruit ripening during postharvest at room temperature. Cold storage for a period of 10 days inhibited this hormonal response related to ripening. Furthermore, avocados stored at cold temperatures underwent a quick response in order to tolerate cold stress leading to changes in endogenous ABA and jasmonates. We conclude that a complex hormonal interplay, rather than ethylene alone, modulates postharvest ripening of avocados and that cold storage can effectively be employed as a technique to prevent avocados from a rapid ripening thanks to the cold stress tolerance mechanisms deployed by fruits through multiple hormonal regulation.
鳄梨（Persea americana Mill.）是一种呼吸跃变型果实，其在室温下的成熟过程强烈依赖于乙烯。然而，其他植物激素在调节鳄梨采后成熟过程中的作用仍知之甚少。鳄梨的最佳成熟状态是在收获后几天达到，具体取决于基因型、生长区域和果实的初始成熟阶段，通常采用冷藏来延迟这一过程。在这里，我们假设鳄梨在室温下的成熟过程不仅受乙烯调控，还受其他植物激素调控。为此，我们分析了在采后 10 天内分别置于 4°C 和 25°C 下的鳄梨的激素特征。在室温下，鳄梨采后成熟过程中观察到一个双相反应。虽然单独的乙烯似乎在果实从冷藏转移到室温的第一个阶段控制着果实的成熟，但在室温下鳄梨成熟过程中发生了复杂的激素相互作用，导致果实逐渐软化。除了乙烯，生长素、赤霉素、茉莉酸和 ABA 似乎也参与了鳄梨果实的采后成熟过程。在室温下贮藏 10 天可抑制与成熟相关的这种激素反应。此外，在冷藏条件下，鳄梨会迅速做出反应以耐受冷胁迫，从而导致内源 ABA 和茉莉酸的变化。我们得出结论，是复杂的激素相互作用而不仅仅是乙烯，调节了鳄梨的采后成熟过程，而冷藏可以有效地作为一种技术来防止鳄梨过快成熟，这要归功于果实通过多种激素调节来部署的冷胁迫耐受机制。
