Department of Genomics and Biotechnology (IFAPA Centro de Málaga), Fruticultura Subtropical y Mediterranea, IFAPA, Unidad Asociada al CSIC, 29140 Churriana, Málaga, Spain.
Department of Crop Ecophysiology (IFAPA Centro de Málaga), Fruticultura Subtropical y Mediterranea, IFAPA, Unidad Asociada al CSIC, 29140 Churriana, Málaga, Spain.
Plant Dis. 2024 Jul;108(7):2111-2121. doi: 10.1094/PDIS-11-23-2316-RE. Epub 2024 Jun 24.
Methyl jasmonate (MeJA) and salicylic acid (SA) are important in mediating plant responses to abiotic and biotic stresses. MeJA and SA can act as elicitors by triggering plant defense responses similar to those induced by pathogens and may even provide long-term protection against them. Thus, exogenous application of MeJA and SA could protect susceptible avocado plants against white root rot (WRR) disease caused by the necrotrophic fungus , one of the main diseases affecting avocado orchards. This work evaluates the effects of MeJA or SA on the physiological and molecular response of susceptible 'Dusa' avocado rootstock and their ability to provide some protection against WRR. The application of MeJA and SA in avocado increased photoprotective mechanisms (nonphotochemical chlorophyll fluorescence quenching) and upregulated the , suggesting the triggering of mechanisms closely related to oxidative stress relief and reactive oxygen species scavenging. In contrast to SA, MeJA's effects were more pronounced at the morphoanatomical level, including functional traits such as high leaf mass area, high stomatal density, and high root/shoot ratio, closely related to strategies to cope with water scarcity and WRR disease. Moreover, MeJA upregulated a greater number of defense-related genes than SA, including a , a key gene in avocado defense against . The overall effects of MeJA increased 'Dusa' avocado tolerance to by inducing a primed state that delayed WRR disease symptoms. These findings point toward the use of MeJA application as an environmentally friendly strategy to mitigate the impact of this disease on susceptible avocado orchards.
茉莉酸甲酯（MeJA）和水杨酸（SA）在介导植物对非生物和生物胁迫的反应中起着重要作用。MeJA 和 SA 可以作为诱导子，通过触发类似于病原体诱导的植物防御反应，甚至可以提供长期的保护作用。因此，外源施用 MeJA 和 SA 可以保护易感鳄梨树免受由坏死真菌引起的白根腐烂（WRR）病的侵害，WRR 病是影响鳄梨树园的主要病害之一。本研究评估了 MeJA 或 SA 对易感 'Dusa'鳄梨砧木的生理和分子反应的影响，以及它们提供对 WRR 病一定保护的能力。MeJA 和 SA 在鳄梨中的应用增加了光保护机制（非光化学叶绿素荧光猝灭）并上调了 ，表明触发了与缓解氧化应激和清除活性氧密切相关的机制。与 SA 相比，MeJA 在形态解剖学水平上的作用更为显著，包括高叶质量面积、高气孔密度和高根/冠比等功能特性，这与应对水分胁迫和 WRR 病的策略密切相关。此外，MeJA 上调了比 SA 更多的防御相关基因，包括一个 ，这是鳄梨抵御 的关键基因。MeJA 的综合作用通过诱导延缓 WRR 病症状的启动状态，提高了 'Dusa'鳄梨对 的耐受性。这些发现表明，应用 MeJA 作为一种环保策略，可以减轻这种疾病对易感鳄梨树园的影响。
