Efecto de la aplicación de una comunidad microbiana de un suelo con historial de sequía en la arquitectura radicular del maíz (Zea mays) bajo estrés por sequía

Abstract

Drought represents the main abiotic threat to global food security, drastically impacting corn (Zea mays) productivity. Faced with this challenge, the use of beneficial microorganisms associated with the rhizosphere emerges as a key biotechnological strategy. The overall objective of this research project was to analyze the effect of applying a microbial community native to soil with a history of drought on the root system architecture (RSA) of corn under water stress. The methodology was implemented under controlled greenhouse conditions, with an experimental design that involved testing treatments inoculated with the native microbial community compared to sterile controls, all subjected to irrigation suspension upon reaching the V5 phenological stage. The study focused on determining root architecture parameters through image analysis (Rhizo Vision Explorer and Image J) to quantify morphological plasticity and hydraulic efficiency. The results showed that inoculation mitigated water stress by acting as a biostimulant that increased early plant vigor by 64 percent. Under drought conditions, inoculated plants maintained an avoidance strategy, sustaining leaf water homeostasis. This tolerance was supported by aggressive phenotypic plasticity that increased rooting depth and promoted a significant increase in the total length of lateral roots. Crucially, a hydraulic adaptation was induced that manifested itself in the expansion of the metaxylem vessels, ensuring axial conductivity and allowing an optimal balance in the root vs. shoot ratio. It is concluded that the microbial community confers a comprehensive reprogramming that combines intensive root exploration with high vascular water transport efficiency, mitigating growth failure under water deficit.