Crop Yield, Ferritin and Fe(II) boosted by Azospirillum brasilense (HM053) in Corn

Abstract

An increasing global population of over 4.5 billion people drives increasing demand for calories—30% of which are satisfied by grain crops, such as maize. High-density farming practices have been implemented but tend to deplete the soil of essential elements resulting in lower nutritional value, notably iron, of cultivated crops. Low iron content in staple crops can contribute over time to severe, even fatal, micronutrient deficiencies. Enhancing grain iron content using post-harvest biofortification strategies can be costly. However, field inoculation using biologics like Azospirillum brasilense (HM053) can be a cost-effective alternative to improving crop nutritional value. Using ion chromatography with chemiluminescence detection, we have shown that maize seeds harvested from outdoor pot-grown plants possessed a four-fold higher iron content as ferrous iron (Fe+2) compared to non-inoculated plants. Seeds from A. brasilense HM053-inoculated plants also contained approximately 13 nmol of ferritin per ground dried weight of kernel compared to 3 nmol from non-inoculated plants. In addition, A. brasilense HM053 inoculation increased crop yield 30–50% relative to non-inoculated plants.

Potential of Biostimulants Based on PGPR Rhizobacteria Native to Benin’s Soils on the Growth and Yield of Maize (<i>Zea mays </i> L.) under Greenhouse Conditions

“…These authors found that the application of peat + B. Thuringiensis had significantly improved the growth and yield of beans. [41] Observed a highly significant increase in growth parameters and overproduction of chlorophyll a and b by maize plants treated with the biostimulant. The larger leaf area, more the plant achieves good photosynthesis, which is favourable to better growth [42] [43].…”

“…Several authors have demonstrated the efficacy of microbial biostimulants on plant yield parameters [49] [50] [51]. It was recently found by [41] that A. brasilense biostimulant HM053 significantly increased maize yield by 53% compared to the control. In our study, biostimulants improved yield parameters in a highly significant way (p < 0.001).…”

Diverse Bacterial Genes Modulate Plant Root Association by Beneficial Bacteria

“…Given the general role that iron availability plays in the ability of microorganisms to thrive and compete in virtually any environment, it is not surprising that iron uptake is also a crucial function for root colonization (17,55). Recently, analysis of iron content in maize treated with the PGPB A. brasilense revealed a significant increase in total iron accumulation in seeds and higher yield (56), suggesting that PGPB can contribute to the iron metabolism of the host plant.…”

Use of Plant Growth Promoting Rhizobacteria in Combination with Chitosan on Maize Crop: Promising Prospects for Sustainable, Environmentally Friendly Agriculture and against Abiotic Stress

“…This strain stored at −85 • C in Mueller Hinton nutrient broth with addition of glycerol (10%) in the laboratory was isolated and identified by [28] and characterized by [7] for its PGPR profile. The ability of P. putida to grow under different temperatures (4,16,25,30,37,40,44,48, and 50 • C) was performed by the method adapted by [29] on Mueller Hinton (MH) liquid nutrient broth inoculated with 100 µL of the bacterial culture of the tested strain for 48 h under agitation. The growth of P. putida was evaluated by reading the optical density (OD) with a spectrophotometer (BioMATE 3S, Thermo scientific, Waltham, MA, USA) at the wavelength of 600 nm and the experiments were performed in three r replicates.…”

“…This rate of improvement in height is higher than the 17% obtained by [47] following the inoculation of maize under greenhouse conditions with chitosan extracted from lobsters combined with strains of Azospirillum lipoferum-P. fluorescens-P. putida. Authors in [48] observed a significant increase in crop yield of 30-50% compared to plants not inoculated with the PGPR strain Azospirillum brasilense (HM053). Various research works have focused mainly on the evaluation of rhizobacteria for their ability to induce improvements in growth and yield parameters in cereals under controlled conditions [12,47,49].…”