Soybean (Glycine max (L.) Merr.) establishes symbiosis with rhizobacteria, developing the symbiotic nodule, where the biological nitrogen fixation (BNF) occurs. The redox control is key for guaranteeing the establishment and correct function of the BNF process. Plants have many antioxidative systems involved in ROS homeostasis and signaling, among them a network of thio- and glutaredoxins. Our group is particularly interested in studying the differential response of nodulated soybean plants to water-deficit stress. To shed light on this phenomenon, we set up an RNA-seq experiment (for total and polysome-associated mRNAs) with soybean roots comprising combined treatments including the hydric and the nodulation condition. Moreover, we performed the initial identification and description of the complete repertoire of thioredoxins (Trx) and glutaredoxins (Grx) in soybean. We found that water deficit altered the expression of a greater number of differentially expressed genes (DEGs) than the condition of plant nodulation. Among them, we identified 12 thioredoxin (Trx) and 12 glutaredoxin (Grx) DEGs, which represented a significant fraction of the detected GmTrx and GmGrx in our RNA-seq data. Moreover, we identified an enriched network in which a GmTrx and a GmGrx interacted with each other and associated through several types of interactions with nitrogen metabolism enzymes.

Background Plant innate immunity relies on a broad repertoire of receptor proteins that can detect pathogens and trigger an effective defense response. Bioinformatic tools based on conserved domain and sequence similarity are within the most popular strategies for protein identification and characterization. However, the multi-domain nature, high sequence diversity and complex evolutionary history of disease resistance (DR) proteins make their prediction a real challenge. Here we present RFPDR, which pioneers the application of Random Forest (RF) for Plant DR protein prediction. Methods A recently published collection of experimentally validated DR proteins was used as a positive dataset, while 10x10 nested datasets, ranging from 400-4,000 non-DR proteins, were used as negative datasets. A total of 9,631 features were extracted from each protein sequence, and included in a full dimension (FD) RFPDR model. Sequence selection was performed, to generate a reduced-dimension (RD) RFPDR model. Model performances were evaluated using an 80/20 (training/testing) partition, with 10-cross fold validation, and compared to baseline, sequence-based and state-of-the-art strategies. To gain some insights into the underlying biology, the most discriminatory sequence-based features in the RF classifier were identified. Results and Discussion RD-RFPDR showed to be sensitive (86.4 ± 4.0%) and specific (96.9 ± 1.5%) for identifying DR proteins, while robust to data imbalance. Its high performance and robustness, added to the fact that RD-RFPDR provides valuable information related to DR proteins underlying properties, make RD-RFPDR an interesting approach for DR protein prediction, complementing the state-of-the-art strategies.

Fungal pathogens cause severe yield losses in lettuce production worldwide. We developed transgenic lettuce lines overexpressing the ch5B chitinase gene from Phaseolus vulgaris under the regulation of the rbcS1 promoter. Molecular characterization confirmed stable transgene integration and expression across the selected lines. In vitro assays demonstrated that transgenic leaf extracts significantly inhibited R. solani mycelial growth. Furthermore, challenges in both seedlings and adult plants showed a significant reduction in lesion areas compared to non-transgenic (NT) controls. Finally, two events were evaluated in field trials, both showing substantial equivalence to the NT variety satisfying international biosafety frameworks for commercial development. Among them, line 3-4 appears as the most promising candidate for further studies, as it showed slightly higher fresh and dry weight compared to the control line under field conditions.

Fungal pathogens cause severe yield losses in lettuce production worldwide. We developed transgenic lettuce lines overexpressing the ch5B chitinase gene from Phaseolus vulgaris (bean) under the regulation of the rbcS1 (ribulose-1,5-bisphosphate carboxylase small subunit) promoter. Molecular characterization confirmed stable transgene integration and expression across the selected lines. In vitro assays demonstrated that transgenic leaf extracts significantly inhibited Rhizoctonia solani mycelial growth. Furthermore, inoculation assays in both seedlings and adult plants in the greenhouse showed a significant reduction in lesion areas compared to non-transgenic (NT) controls. Finally, two lines were evaluated in field trials, both showing agronomic substantial equivalence to the NT, satisfying international biosafety frameworks for commercial development. Among them, the ch5B 3-4 line appears to be the most promising candidate for further studies, as it showed slightly higher fresh weight compared to the NT under field conditions.:

The TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins are a plant-specific family proposed to function as peripheral membrane proteins that contribute to abiotic stress tolerance in Arabidopsis, likely by maintaining cell wall integrity through brassinosteroid signaling. In previous work of our group, we identified a GmTTL gene that showed differential abundance in the polysome-associated RNA (PAR) fraction in nitrogen-fixing soybean plants under water restriction (WR). This finding, together with the lack of knowledge about this gene family in soybean, prompted us to perform a genome-wide characterization of this family. In this work, using the Glycine max v4.0 proteome, we identified ten homologs (GmTTL1–GmTTL10) distributed across five chromosomes. Phylogenetic and structural analyses grouped these genes into three clades and revealed a highly conserved exon–intron organization, as well as conserved numbers and arrangements of TPR and TRXL motifs. Moreover, to investigate their potential biological functions, we reanalyzed by STRING the co-expression module enriched with 367 downregulated genes at the PAR level to which GmTTL7 belong. Interestingly, the protein–protein interaction (PPI) network analysis showed the over-representation of Gene Ontology (GO) terms associated with “cellular anatomical entity”, “membrane”, “cell periphery”, “cell wall modification”, “cell wall organization or biogenesis”, and “nitrate assimilation”. Notably, the PPI network revealed a novel predicted functional association between GmTTL and two nitrate reductase enzymes in nitrogen-fixing plants subjected to WR. This study provides a framework for future functional studies of GmTTL proteins and their contribution to abiotic stress adaptation in soybean.