The European “Green Deal” policies are shifting toward more sustainable and environmentally conscious agricultural practices, reducing the use of chemical fertilizer and pesticides. This implies exploring alternative strategies. One promising alternative to improve plant nutrition and reinforce plant defenses is the use of beneficial microorganisms in the rhizosphere, such as “Plant-growth-promoting rhizobacteria and fungi”. Despite the great abundance of iron (Fe) in the Earth’s crust, its poor solubility in calcareous soil makes Fe deficiency a major agricultural issue worldwide. Among plant promoting microorganisms, the yeast Debaryomyces hansenii has been very recently incorporated, for its ability to induce morphological and physiological key responses to Fe deficiency in plants, under hydroponic culture conditions. The present work takes it a step further and explores the potential of D. hansenii to improve plant nutrition and stimulate growth in cucumber plants grown in calcareous soil, where ferric chlorosis is common. Additionally, the study examines D. hansenii’s ability to induce systemic resistance (ISR) through a comparative relative expression study by qRT-PCR of ethylene (ET) biosynthesis (ACO1), or ET signaling (EIN2 and EIN3), and salicylic acid (SA) biosynthesis (PAL)-related genes. The results mark a significant milestone since D. hansenii not only enhances nutrient uptake and stimulates plant growth and flower development but could also amplify induced systemic resistance (ISR). Although there is still much work ahead, these findings make D. hansenii a promising candidate to be used for sustainable and environmentally friendly integrated crop management.

Rice (Oryza sativa L.) is a very important cereal worldwide, since it is the staple food for more than half of the world’s population. Iron (Fe) deficiency is among the most important agronomical concerns in calcareous soils where rice plants may suffer from this deficiency. Current production systems are based on the use of high-yielding varieties and the application of large quantities of agrochemicals, which can cause major environmental problems. The use of beneficial rhizosphere microorganisms is considered a relevant sustainable alternative to synthetic fertilizers. The main goal of this study was to determine the ability of the nonpathogenic strain Fusarium oxysporum FO12 to induce Fe-deficiency responses in rice plants and its effects on plant growth and Fe chlorosis. Experiments were carried out under hydroponic system conditions. Our results show that the root inoculation of rice plants with FO12 promotes the production of phytosiderophores and plant growth while reducing Fe chlorosis symptoms after several days of cultivation. Moreover, Fe-related genes are upregulated by FO12 at certain times in inoculated plants regardless of Fe conditions. This microorganism also colonizes root cortical tissues. In conclusion, FO12 enhances Fe-deficiency responses in rice plants, achieves growth promotion, and reduces Fe chlorosis symptoms.

The aim of this work was to study the nutritional value of game meat through the fulfillments of Dietary Reference Intakes (DRI) for trace elements (Co, Cr, Cu, Fe, Ni, Se, and Zn). A probabilistic model (@Risk) was developed based on the consumption data of hunter-consumers obtained from a previously published survey. Two game species widely consumed in Europe were selected: red deer (Cervus elaphus) and wild boar (Sus scrofa). Red deer muscle had the highest content of Cr (0.25 mg/kg) and Zn (44.3 mg/kg) and wild boar muscle recorded the highest Cu (2.23 mg/kg), Ni (0.60 mg/kg), and Se (0.19 mg/kg), showing statistically significant differences between the two species for these elements. No statistically significant differences were found for Fe between both game species (red deer: 52.9 mg/kg and wild boar: 53.3 mg/kg). Co content in this kind of meat was negligible for both species. The results obtained from the simulation of the probabilistic model with red deer indicated that a consumption once per week of this meat fulfills Cr, Fe, and Zn DRIs for the 95th percentile in hunter-consumers. Regarding wild boar, the values obtained also fulfill the Fe DRI and were between 61 and 75% for the rest of the trace elements analyzed.

Verticillium wilt, caused by the soilborne fungus Verticillium dahliae , and iron (Fe) deficiency are major stresses impacting valuable crops in the Mediterranean basin. The plant response to these stresses consists of overlapping pathways that, coupled with the emerging use of endophytic fungi as biological control agents (BCAs) and plant biostimulants, enables the study of their potential to mitigate co‐occurring biotic stresses and nutritional deficiencies such as Fe deficiency. To this end, Arabidopsis thaliana plants of the “Columbia” ecotype grown in calcareous soil were inoculated with the non‐pathogenic strain Fusarium oxysporum FO12 and/or with the defoliating pathotype of V. dahliae strain V180. Plant growth, plant mineral uptake, and disease progression, along with the molecular quantification of FO12 and V180 fungal biomass and the relative expression of ISR‐, SAR‐, and Fe deficiency‐related genes in shoots, were evaluated. The results revealed that plants inoculated with the FO12 strain increased growth, leaf chlorophyll concentration (SPAD index), and phosphorus (P; 126%) and Fe (9%) contents, partially due to ethylene (ET) and Iron Man peptides (IMA). In addition, FO12 reduced the severity of symptoms by more than 85%. This reduction in disease severity may be attributed to a direct competitive effect on V180 progression and to the induction of several defence‐associated genes related to ET and SA synthesis and signaling. This bidirectional crosstalk between Fe deficiency responses and plant defences triggered by FO12 mainly through ET can improve plant resilience while reducing reliance on agrochemicals, offering a sustainable multifaceted tool for crop protection and nutrition management.

Background and aims: Endophytic fungi such as the non-pathogenic strain Fusarium oxysporum FO12 have emerged as useful allies for plants as they could promote plant growth and protect from stresses. However, its performance under natural soil conditions and the effectiveness of different inoculation methods have not been evaluated before. The objectives of this study were to assess the ability of FO12 to enhance plant growth and nutrition in sunflower and wheat plants grown on soils differing in texture and organic matter content, pH, and nutrient availability, and to compare the effectiveness of two different inoculation methods (seed dressing, and soil treatment). Methods: Firstly, we developed in vivo experiments to evaluate the ability of FO12 to increase nutrient availability. Secondly, we assessed the potential of FO12 for enhancing plant growth and nutrition in sunflower and wheat plants (in vivo) grown on four non-calcareous and calcareous soils with different nutrients availability (Fe, Zn and P); and the effectiveness of two different FO12 application methods, seed dressing (Sd) and soil treatment (St). Results: FO12 modified the pH of the culture medium, and significantly increased the potential Fe availability by 202%, and Zn availability by 52% and P availability by 7% (but not significantly) compared to the non-inoculated control (in vitro). Both FO12 application methods boosted plant growth by increasing plant height as well as sunflower and wheat reproductive biomass by up to 27 − 31% and 28–34% in non-calcareous and calcareous soils (in vivo), respectively. FO12 additionally increased macro- and micronutrient uptake, especially with St. Finally, the fungus induced changes in the plant phytohormone profile, mainly with Sd, which consistently increased jasmonic acid (47%), jasmonyl isoleucine (511%) and 1-Aminocyclopropane-1-carboxylic acid (226%), and decreased indoleacetic acid (39%) across all four soils and in both crops, in comparison with the non-inoculated plants. Conclusions: FO12 stimulates plant growth by altering soil properties and physiological plant processes, and its effects on plant nutrition and production depend on the plant species and soil type. Graphical