Root rot caused by Phytophthora cinnamomi Rands, is one of the main factors that limits avocado production worldwide; silicon as a defense inducer seems to be a viable strategy to integrate into the management of this disease. Hereby, the present study evaluated the induction of resistance with silicon in Hass avocado plants inoculated with P. cinnamomi, as a possible alternative to conventional agrochemical management. A potassium silicate solution (10 mL, 0.2 M expressed as SiO₂) was applied by irrigation, for ten days before inoculation with P. cinnamomi in Hass avocado plants. Leaf samples were taken at 3, 24, 144, and 312 h after inoculation with the pathogen. Peroxidase (POD) and polyphenol oxidase (PPO) enzymes had their highest activity 3 h after pathogen inoculation (p < .05). There was a decrease in the activity of the enzyme phenylalanine ammonialyase (PAL), in the content of total phenols, and the inhibition capacity of the DPPH^● radical, between 3 h and 24 h in the plants with the inducer and inoculated with P. cinnamomi (p < .05). The results suggest a beneficial effect of silicon as a defense inducer in Hass avocado plants, manifested in the activation of enzymatic pathways related to the regulation of oxidative stress and the synthesis of structural components. Therefore, the application of silicon as a defense inducer emerges as a strategy to include in the integrated management of the disease caused by P. cinnamomi in Hass avocado.

Objective: The main objective of this study is to evaluate the chemical and bioactive properties of Eugenia stipitata (Myrtaceae) fruit seeds collected in the Andean region of Colombia using an ethanolic extract, a dichloromethane fraction (DF), and a hydroalcoholic residue.Methods: E. stipitata seeds were evaluated using bromatological analysis; these were macerated (ethanol 96%) and partitioned (dichloromethane). Phytophenols composition of the samples was tested by high-pressure liquid chromatography-mass spectrometry and Folin–Ciocalteu method, then calculated as gallic acid equivalents (GAEs). Antiradical capacity was tested by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 3-ethylbenzthiazoline-6- sulfonic acid (ABTS•+) and inhibitory concentration 50% (IC50) was calculated; antioxidant capacity was determined using ferric reducing antioxidant power, oxygen radical absorbance capacity, and OH• radical and hemolysis inhibition assays. Anthelmintic activity against Panagrellus redivivus and ovine gastrointestinal (GI) nematodes and toxicity on human blood cells were tested.Results: E. stipitata seeds contain protein, sulfur, boron, iron, and copper. The ethanolic extract exhibited significant anthelmintic activity against free-living and GI nematodes, which would be associated with the phytophenols content, mostly tannins (29.14 g GAE/100 g). DF displayed the highest antiradical capacity in DPPH• and ABTS•+ (IC50: 2.65 and 0.33 mg/l, respectively) methods, antioxidant capacity, and hemolysis inhibition of human erythrocytes (IC50: 200 mg/l). There were no toxic metabolites to human blood cells.Conclusion: These findings would be useful for promoting the use of E. stipitata seeds, collected in the Colombian Andean region, in biotechnological processes. This is the earliest paper showing a study carried out in Colombia with an interest in evaluating chemical and biological characteristics of E. stipitata seeds.

Phytophthora cinnamomi causes one of the most important diseases in avocado crop and its chemical management represents 25% of the production cost per year. Induction of plant defense responses by elicitors is a promising strategy that is compatible with sustainable agriculture. This study aimed to evaluate the effect of curdlan application on the induction of defense responses in avocado plants against P. cinnamomi. The trials were conducted under greenhouse conditions, and curdlan leaf spraying was performed one day before the inoculation of the pathogen. The results showed that the application of elicitor significantly increased the protection of avocado plants against P. cinnamomi, decreasing the injury and wilting. The Curd + Phy treatment improved the defenses of plants by increasing the enzymes peroxidase (POD) and polyphenol oxidase (PPO) in the first 3 h after inoculation and increasing the enzymes superoxide dismutase (SOD) and phenylalanine ammonium lyase (PAL) 144 h after inoculation (p < 0.05). Also, chlorophyll and carotenoid content increased or remained stable in Curd + Phy treatment. Therefore, these results suggest that curdlan increases the protection against P. cinnamomi and its protection could be due to an increase in the activity of the enzymes related to the phenylpropanoid pathway as well as the effect on chlorophyll and carotenoids.

Pattern-triggered immunity (PTI) is generally considered a conserved defense layer, but how different pattern-recognition receptors (PRRs) shape immune specificity in woody perennials remains poorly resolved. We investigated whether the bacterial MAMP flg22 and the fungal elicitor xyn11/EIX trigger generic or specialized PTI states in sweet cherry (Prunus avium). We identified and functionally characterized PaFLS2 as a plasma membrane-localized, flg22-responsive receptor-like kinase, and compared its structural architecture with the previously characterized xyn11/EIX receptor PaEIX2. Residue-interaction profiling revealed a conserved FLS2 architecture and greater modular plasticity in EIX2-like receptors. Both elicitors activated PTI-associated responses, but generated distinct resistance outcomes: flg22 preferentially restricted Pseudomonas syringae pv. syringae, whereas xyn11/EIX enhanced resistance to Botrytis cinerea and produced broader defense-associated reprogramming. Integration of gene expression, orthology-informed regulatory networks, phytohormone profiling and multivariate analyses showed that flg22 and xyn11/EIX establish partially overlapping yet discrete immune configurations. These findings support a model in which PRR identity does not merely activate PTI but biases sweet cherry immunity toward distinct hormone-associated regulatory states that shape defense specificity.