Olivares Daniela, García-Rojas Miguel, Ulloa Pablo A, Riveros Aníbal, Pedreschi Romina, Campos-Vargas Reinaldo, Meneses Claudio, Defilippi Bruno G
Instituto de Investigaciones Agropecuarias, INIA-La Platina, Santa Rosa 11610, Santiago 8831314, Chile.
ANID-Millennium Science Initiative Program-Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago 8370186, Chile.
Plants (Basel). 2022 Jul 5;11(13):1781. doi: 10.3390/plants11131781.
1-Methylcyclopropene (1-MCP) is used for extending the postharvest life of the avocado during storage. Evaluated the effect of 1-MCP application at different times after harvest, i.e., 0, 7, 14, and 21 d at 5 °C, to identify the threshold of the ethylene inhibition response in "Hass" avocado. Our results showed that fruits from two maturity stages at harvest: low dry matter (20-23%) and high dry matter (27%). Changes in ethylene production rates and transcript accumulation of genes involved in ethylene metabolism were measured at harvest and during storage. 1-MCP treated fruit up to 14 d of storage showed similar values of firmness and skin color as fruit treated at harvest time. In contrast, when the application was performed after 21 d, the fruit showed ripening attributes similar to those of the untreated ones. To further understand the molecular mechanisms responsible for the lack of response to 1-MCP at 21 d of storage, transcriptomic analysis was performed. Gene ontology analyses based on the DEG analysis showed enrichment of transcripts involved in the 'response to ethylene' for both maturity stages. All genes evaluated showed similar expression profiles induced by cold storage time, with a peak at 21 d of storage and an increased softening of the fruit and peel color. This was a two-year field study, and results were consistent across the two experimental years. Our results should help growers and markets in selecting the optimal timing of 1-MCP application in "Hass" avocados and should contribute to a deeper understanding of the molecular mechanisms of the avocado ripening process.
1-甲基环丙烯（1-MCP）用于延长鳄梨在储存期间的采后寿命。评估了在收获后不同时间（即5℃下0、7、14和21天）施用1-MCP的效果，以确定“哈斯”鳄梨乙烯抑制反应的阈值。我们的结果表明，收获时处于两个成熟阶段的果实：低干物质（20-23%）和高干物质（27%）。在收获时和储存期间测量了乙烯产生率的变化以及参与乙烯代谢的基因的转录本积累。储存14天内用1-MCP处理的果实，其硬度和果皮颜色值与收获时处理的果实相似。相比之下，在21天后进行处理时，果实表现出与未处理果实相似的成熟特征。为了进一步了解在储存21天时对1-MCP无反应的分子机制，进行了转录组分析。基于差异表达基因（DEG）分析的基因本体分析表明，两个成熟阶段中参与“乙烯反应”的转录本均有富集。所有评估的基因在冷藏时间诱导下表现出相似的表达谱，在储存21天时达到峰值，果实和果皮颜色变软加剧。这是一项为期两年的田间研究，两个实验年份的结果一致。我们的结果应有助于种植者和市场选择在“哈斯”鳄梨中施用1-MCP的最佳时机，并有助于更深入地了解鳄梨成熟过程的分子机制。
