Common Bean Yield and Zinc Use Efficiency in Association with Diazotrophic Bacteria Co-Inoculations

Abstract

Enrichment of staple food with zinc (Zn) along with solubilizing bacteria is a sustainable and practical approach to overcome Zn malnutrition in human beings by improving plant nutrition, nutrient use efficiency, and productivity. Common bean (Phaseolus vulgaris L.) is one of a staple food of global population and has a prospective role in agronomic Zn biofortification. In this context, we evaluated the effect of diazotrophic bacterial co-inoculations (No inoculation, Rhizobium tropici, R. tropici + Azospirillum brasilense, R. tropici + Bacillus subtilis, R. tropici + Pseudomonas fluorescens, R. tropici + A. brasilense + B. subtilis, and R. tropici + A. brasilense + P. fluorescens) in association with soil Zn application (without and with 8 kg Zn ha−1) on Zn nutrition, growth, yield, and Zn use efficiencies in common bean in the 2019 and 2020 crop seasons. Soil Zn application in combination with R. tropici + B. subtilis improved Zn accumulation in shoot and grains with greater shoot dry matter, grain yield, and estimated Zn intake. Zinc use efficiency, recovery, and utilization were also increased with co-inoculation of R. tropici + B. subtilis, whereas agro-physiological efficiency was increased with triple co-inoculation of R. tropici + A. brasilense + P. fluorescens. Therefore, co-inoculation of R. tropici + B. subtilis in association with Zn application is recommended for biofortification and higher Zn use efficiencies in common bean in the tropical savannah of Brazil.

Cross Talk Between Zinc-Solubilizing Bacteria and Plants: A Short Tale of Bacterial-Assisted Zinc Biofortification

“…A wide range of ZSB, including both groups such as gram-positive and gram-negative bacteria, demonstrated their competence in biofortification. Bacillus, in particular, showed a profound role in Zn biofortification in numerous food crops (8,12,38,55,58,(167)(168)(169)(170)(171)(172). The important crops such as maize (38,54,58,173,174), rice (59,60,171,175,176), and wheat (8,11,31,32,167,177) have been studied extensively for Zn biofortification in response to ZSB inoculants as the grain parts from these crops offer the most important staple foods on a broad scale worldwide.…”

Fósforo y Bacillus subtilis en absorción y remoción de micronutrientes en Phaseolus vulgaris L.

“…La posible razón que explica la alta absorción de micronutrientes está relacionada con la producción de nódulos promovidos por la fertilización fosforada como lo mencionan Amare et al (2014); Shanka et al (2018). La inoculación con PGPR ha sido asociada por incrementar la bio-fortificación de micronutrientes en granos de frijol común (Talaat et al, 2015;Jalal et al, 2021). A excepción del Zn, la inoculación con Bs incrementó la concentración de micronutrientes (Cuadro 1).…”

Nanozinc and plant growth-promoting bacteria improve biochemical and metabolic attributes of maize in tropical Cerrado

“…Seed inoculation with PGPBs is a promising strategy to promote plant growth and development by facilitating nutrient use efficiency, modulating hormonal activities, and inhibiting pathogenic infestation ( Di Benedetto et al., 2017 ; Kumar et al., 2019 ). In addition, PGPBs contribute to the synthesis of secondary metabolites, water absorption, nutrient [phosphorus (P), Zn, and potassium (K)] solubilization, and tolerance to biotic and abiotic stresses ( Hungria et al., 2018 ; Jalal et al., 2021 ; Lopes et al., 2021 ). The inoculants of the genus Azospirillum are being recognized in the biosynthesis of auxin synthesis, nutrient cycling and availability, and biological nitrogen (N) fixation by reducing N 2 into ammonia (NH 3 ) ( Bhat et al., 2019 ; Carrillo-Flores et al., 2022 ; Galindo et al., 2022 ).…”

“…Zinc fertilization in combination with inoculation of Azospirillum brasilense ( A. brasilense ) increases Zn use efficiency and accumulation, and yield of cereal crops grown in tropical environments ( Galindo et al., 2021 ). In addition, B. subtilis and P. fluorescens are being recognized as the most effective inoculants to solubilize Zn and P, and improve plant growth and development under different climatic conditions ( Rosa et al., 2020 ; Ahmad et al., 2021 ; 2022b ; Jalal et al., 2021 ; Jalal et al., 2022a ).…”