Co-Inoculation of Bacillus spp. for Growth Promotion and Iron Fortification in Sorghum

Mansani Manasa,Bee Hameeda,Subramaniam Gopalakrishnan,Polapally Ravinder,Ali Tan Kee Zuan,Hesham Ali El Enshasy,Hazem S Kassem,R Z Sayyed,Maizatulakmal Yahayu,Vadlamudi Srinivas

doi:10.3390/su132112091

Abstract

Seven Bacillus spp. isolated from the marine water and the rhizosphere of the medicinal plant Coscinium fenestratum were studied to produce plant growth promotion (PGP) traits invitro. Among the seven isolates, MMRH22 and RHPR20 produced copious amounts of PGP traits. Based on the 16S rRNA sequence, the two potent bacterial isolates, RHPR20 and MMRH22, were identified as Bacillus mojavensis and Bacillus cereus, respectively. A compatibility test between the isolates RHPR20 and MMRH22 revealed they are compatible and can be used as a consortium. Both isolates were evaluated for the plant growth promotion and the biofortification of sorghum under greenhouse conditions. Treatments included the application of MMRH22, RHPR20, their consortium (RHPR20 + MMRH22), and an uninoculated control. Inoculation with bacterial cultures resulted in a significant increase in the plant height; the number of leaves; the leaf area; the root, shoot, and leaf weight; and the yield of sorghum at 30 and 60 days after sowing (DAS). The scanning electron micrograph of the sorghum plant roots revealed extensive colonization in the plants treated with the bacterial cultures compared to the uninoculated control. The sorghum grains obtained after final harvest were analyzed for their nutrient content by ICP–OES. The biofortification in sorghum grains was varied and was found to enhance the iron content up to 97%. This study revealed that treatments with microbial consortia enhance plant growth, yield, and iron content, which could combat nutrient deficiencies in plants and humans.

Highlights

Introduction conditions of the Creative CommonsIron deficiency is highly prevalent among the global population, and it can result in iron deficiency anemia (IDA), impairment in physical activity, mental retardation, child death, and stillbirth
The sequences obtained were aligned against similar sequences in GenBank, and the results revealed that RHPR20 was similar to Bacillus mojavensis and MMRH22 was similar to Bacillus cereus
Our results showed that Bacillus spp. isolated from various origins can synergistically enhance the growth and the uptake of iron content of sorghum

Summary

Introduction

Introduction conditions of the Creative CommonsIron deficiency is highly prevalent among the global population, and it can result in iron deficiency anemia (IDA), impairment in physical activity, mental retardation, child death, and stillbirth. Sustainability 2021, 13, 12091 and the edible parts of plants, such as vegetables and fruits, and reduced iron uptake by plants. This problem can be addressed by using nutrient supplements or through the biofortification of crop plants with rhizobacteria. This approach is a sustainable alternative to counter nutrient deficiencies [1,2]. Sorghum is one of the most important cereal crops that occupy the fifth position globally [3]. It is the dietary staple food for around 500 million people in more than

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Conclusion