BUSCADOR RECOLECTA

Description of the project

Context: In the face of anthropogenic global change, Mediterranean oak-dominated ecosystems confront increased biotic (ungulate herbivory) and abiotic (drought) stressors, compromising forest regeneration. Restoration measures are imperative to address this scenario.

Aims: This study assesses the impact of different mitigation measures on the survival and biochemical traits of two widespread Mediterranean oak species.

4. Description of the dataset

The dataset encompasses information from the planting of 300 Quercus seedlings in Cabañeros (Quercus ilex; N=200) and Doñana (Quercus suber; N=100), subjected to various treatments: cotyledon/acorn removal, seedling age (1 vs. 2-year-old), and herbivore protection (fenced vs. non-fenced).

Monthly measurements of the seedlings were conducted from February to September 2021. Each visit consisted of recording: the seedling survival status (alive vs. dead), the damage caused by biotic and abiotic stress agents and the identification of the main stress agent, namely wild boar, deer, rabbit, fungi, insect or drought.

We considered the main stress agent the one leading to the plant death, or, in the case of surviving seedlings, the one identified with the highest intensity score.

To compare seedling physiological leaf biochemical responses to different treatments and plant ages, several non-destructive measures of chlorophyll, anthocyanin and flavonoid concentrations and the nitrogen balance index (NBI) were taken using the leaf clamp fluorescence sensor Dualex ® TMScientific+, Force One. The Dualex measures were taken on 5 leaves previously marked, from top to bottom, only in alive seedlings.

• Romanticismo (1823-1860).
• Realismo y naturalismo (1860-1895)

Iron deficiency in crops significantly reduces yield, impacting agricultural productivity worldwide. To address this issue, synthetic Fe chelates are commonly applied, but their prolonged use poses environmental risks. Thus, inoculation of plant growth-promoting bacteria (PGPB) rises as an alternative to enhance iron uptake in crops while minimizing reliance on synthetic chelates. This study aimed to examine the influence of Pseudomonas RMC4 inoculation and pyoverdine application on cucumber plants cultivated hydroponically under Fe deficiency conditions. Evaluations included the SPAD index, plant biomass, root morphology, Fe-chelate reductase activity, gene expression, and ionomic analysis. Following Fe deficiency, Pseudomonas RMC4 inoculation improved the SPAD index, increased dry weight, enhanced root development, and facilitated Fe acquisition mechanisms. This improvement was observed with bacterial inoculation or pyoverdine application alongside an insoluble Fe source (ferrihydrite). Overall, the results suggest the beneficial impact of Pseudomonas RMC4 inoculation in alleviating symptoms of Fe deficiency. Future studies will investigate bacterial application under field conditions to assess its potential in reducing the need for synthetic Fe chelates in crop production.

In the present work, the efficiency of Pseudomonas RMC4 to mitigate Fe-deficiency symptoms of cucumber plants under hydroponic conditions was evaluated. The following determinations were performed: SPAD index, plant biomass, root morphology, ferric-chelate reductase activity, gene expression, and ionomic analysis. The results suggest that Pseudomonas RMC4 could help cucumber plants to reduce Fe-deficiency symptoms through plant development and improve the plant´s inherent mechanisms for Fe uptake, although, Pseudomonas RMC4 does not completely solve the Fe defficiency problem.