Obtención de lignina a partir de agro-residuos y su uso como bioestimulante en plantas de lechuga sometidas a estrés por salinidad

"El aumento de la población humana desde el inicio de los asentamientos agrícolas ha impulsado tanto el progreso como el desbalance climático, afectando directamente la agricultura a través de fenómenos como la salinización de suelos. Para mitigar estos problemas, la bioestimulación surge como una estrategia innovadora que promueve defensas naturales en las plantas sin residuos dañinos. Entre los bioestimulantes, la lignina se destaca por su sofisticación y abundancia en la naturaleza, representando un componente importante de las paredes celulares vegetales. En Coahuila, México, las lignina extraíble en cáscaras de nuez es abundante ya que es el principal estado productor de nogal, sin embargo lo residuos de su producción son desaprovechados Este trabajo evalúa el efecto de diferentes concentraciones de lignina (10 ppm, 50 ppm, y 100 ppm) extraída mediante ácidos suaves de fuentes sustentables, sobre la Lechuga Great Lake de la familia Asteraceae, comparándolas con un control sin tratamiento (0 ppm). Los resultados más destacados se obtuvieron con la concentración de 50 ppm, mostrando un incremento del 66.2% en peso fresco de raíz (PFR), 31% en peso seco de raíz (PSR) y un 58% en peso seco de hoja (PSH) en comparación con el control. Además, la síntesis de prolina mostró un aumento significativo del 70% con 10 ppm, lo que indica un beneficio adicional en condiciones de estrés"

"The increase in population has driven development across multiple sectors, including agriculture, but has also contributed to a climatic imbalance that directly impacts crop productivity. This imbalance, manifested in phenomena such as soil salinization, seeks to be controlled through sustainable approaches. In this context, bio-stimulation emerges as an innovative tool that activates the natural defenses of plants without leaving harmful residues. Lignin, a major component of plant cell walls, has proven to be an effective bio-stimulant, having been applied to species of the Solanaceae and Gramineae families. According to analyses conducted by the Center for Applied Chemical Research (CIQA), walnut shells are composed of 18% lignin, making them an excellent source for processing this bio-stimulant. It is estimated that the state of Coahuila de Zaragoza has around 22,000 hectares of walnut production, accounting for 11.5% of national production, making it the perfect location to synthesize lignin for improving the physiological behavior of plant species while also utilizing agro-industrial residues. This study evaluated the impact of different lignin concentrations (0, 10, 50, and 100 ppm) on Lactuca sativa var. Great Lake (Asteraceae family). The results indicated that the 50 ppm treatment increased fresh root weight (FRW) by 66.2%, dry root weight (DRW) by 31%, and dry leaf weight (DLW) by 58% compared to the control. Additionally, the 10 ppm concentration promoted a 70% increase in proline synthesis. These findings highlight the potential of lignin as a sustainable bio-stimulant, especially in horticultural crops. The use of lignin-rich walnut shells in regions like Coahuila (producer of 11.5% of the national walnut crop) reinforces its economic and environmental viability. This study lays the groundwork for exploring the effects of lignin on other species and advancing towards more sustainable agricultural practices"