Resumen en Inglés:

Abstract Root-knot nematodes (Meloidogyne incognita) severely limit cotton (Gossypium spp.) productivity, with conventional control methods facing ecological and efficacy challenges. Here, we evaluate a fungal peptidogalactomann (pGM), derived from Cladosporium herbarum (commercially formulated as Hariman), as a novel biocontrol agent that primes plant defenses against nematode infection. Under greenhouse conditions, foliar application of pGM at 100 μg·mL⁻¹ resulted in an 83% reduction gall formation compared to untreated controls and yielded a four-fold increase in resistant plants (gall index = 1.5 vs. 3.2 in controls; *p* < 0.01). Nematode egg production was reduced by 60% at 120 days post-inoculation. pGM triggered a biphasic defense response, evidenced by a remarkable 40,000-fold upregulation of the systemic acquired resistance gene PR1 and transient activation of phenylpropanoid (PAL) and jasmonate (LOX2) pathways. Notably, pGM supported healthy plant growth without phytotoxicity, contrasting with the phytotoxicity often associated with chemical nematicides. These findings indicate that pGM has strong potential as a sustainable alternative for M. incognita management in cotton, primarily by enhancing host immunity rather than exerting direct nematode toxicity. Further field trials are necessary to validate its effectiveness and to evaluate its integration into integrated pest management strategies.

Resumen en Inglés:

Abstract Recurrent drought episodes, increasingly intensified by climate change, pose a growing threat to global food security by severely limiting crop productivity. Major latex-like proteins (MLPs) play crucial roles in drought tolerance, acting as regulators of stress responses. However, their involvement in adaptation to recurrent drought stress remains poorly understood. In this study, we investigated the transcriptional dynamics of MLP genes during repeated dehydration and rehydration cycles in Arachis duranensis, a tropical wild species highly resilient to drought. In silico expression profiling of 36 A. duranensis MLP genes revealed their broad involvement in recurrent drought responses, with most patterns consistent with the ‘revised-response’ category of dehydration memory genes. qRT-PCR analysis further confirmed the activation of the abscisic acid (ABA) signaling pathway during recurrent drought in A. duranensis. Functional characterization of the candidate memory gene AdMLP11 in transgenic tobacco showed that its overexpression enhances tolerance to moderate and severe recurrent drought, likely through its role as a positive regulator of phytohormone-mediated defense pathways. These findings provide novel insights into the role of MLPs in transcriptional memory and drought adaptation in wild Arachis, highlighting AdMLP11 as a promising target for biotechnological strategies to develop climate-resilient crops.

Resumen en Inglés:

Abstract Virus-induced gene silencing (VIGS) has evolved from a conceptual demonstration of antiviral defense into a pivotal reverse-genetics platform for plant functional genomics. By exploiting engineered DNA- or RNA-based viral vectors, VIGS enables rapid, sequence-specific transcript knockdown through RNA-mediated degradation of target transcripts. Recent refinements in vector design, inoculation strategies, and viral species selection, such as TRV, BSMV, and FoMV, have expanded its application to previously recalcitrant plants, including major crops and emerging weed models. In weeds, functional genomics remains particularly challenging due to high genetic variability, limited genomic resources, and incompatibility with conventional viral vectors and transformation systems. In this context, VIGS provides a tractable approach to investigate genes associated with herbicide resistance, metabolic adaptation, and stress tolerance. Beyond weed biology, its application to studies of immune signaling, hormonal crosstalk, and secondary metabolism highlights VIGS as a versatile biotechnology for elucidating gene function and supporting next-generation strategies in plant improvement and integrated pest management.

Resumen en Inglés:

Abstract Water scarcity impacts soybean cultivation and productivity globally. The ability of plants to withstand drought stress involves complex molecular and physiological mechanisms that facilitate the restoration and maintenance of cellular homeostasis. This study identified genes associated with carbohydrate metabolism and GABA shunt pathway that respond to water deficit in two soybean varieties. These varieties exhibited contrasting responses to water scarcity, and were subjected to two distinct cropping systems. In the drought-tolerant variety, a strategy for conferring tolerance was observed through the pre-emptive priming of the drought response. By applying multivariate analysis, we identified a pivotal gene, GmBAM-like 1, which responds to water scarcity. GmBAM-like 1 encodes a β-amylase and showed rapid activation and elevated expression levels in root tissues of the tolerant variety, suggesting its potential involvement in the drought tolerance response. Transgenic Arabidopsis plants overexpressing GmBAM-like 1 demonstrated enhanced tolerance to salt and osmotic stress, as evidenced by increased survival and germination rates. Additionally, after drought stress, these plants showed higher transpiration rates, larger leaf area, and greater relative water content upon rehydration. These findings demonstrate the potential of integrating the GmBAM-like 1 gene into plant breeding programs to develop cultivars with improved tolerance to water, salt, and osmotic stresses.