Diversity and abundance of culturable nitrogen‐fixing bacteria in the phyllosphere of maize

Abstract

Aims: The present study aimed at gaining an insight into the abundance and genetic diversity of culturable N-fixing epiphyte bacteria on the phyllosphere of maize in arid and semi-arid regions of Iran. Methods and Results: Leaf samples of the maize variety, 'single cross 704' (Zea mays L.) were collected from different locations in Iran. The community of culturable N-fixing epiphyte bacteria present was examined by 16S rRNA sequencing, BOXAIR-polymerase chain reaction (PCR) and restricted fragment length polymorphisms analysis of 16S rRNA gene (16S-RFLP). Approximately, 31Á82% of the 242 isolates were identified as N-fixers by cultivation of bacteria in Rennie medium and detection of their nifH gene. The N-fixers were affiliated with four bacterial phyla: Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. 16S rRNA sequencing detected 16 genera and 24 different species in the identified phyla. The most dominant genus was Bacillus and the species identified were B. pumilus, B. amyloliquefaciens, B. subtilis, B. paralicheniformis, B. licheniformis, B. niabensis and B. megaterium. In total, 22 RFLP groups were present among the isolates originally identified as N-fixing bacteria. BOXAIR-PCR showed that there was a low similarity level among the N-fixing bacteria isolates, and genetic differentiation of individual strains was relatively great. Conclusions: Our findings suggest that nitrogen-fixing epiphyte bacteria on the phyllosphere of maize may provide significant nitrogen input into arid and semi-arid ecosystem. Significance and Impact of the Study: This research implies that phyllosphere epiphyte diazotrophs have much to offer in sustainable agriculture and can be an alternative to chemical N-fertilizers for providing nitrogen to crops arid and semi-arid regions.

Antagonistic Strain Bacillus amyloliquefaciens XZ34-1 for Controlling Bipolaris sorokiniana and Promoting Growth in Wheat

“…For example, B. amyloliquefaciens S76-3 produces three classes of cyclic lipopeptides, including Iturin, Plipastatin and Surfactin, which exhibit strong antifungal activity against the toxigenic Fusarium graminearum [22]. Furthermore, B. amyloliquefaciens has shown the ability to promote plant growth [24,25]. The potential contribution to plant growth promotion by B. amyloliquefaciens UCMB5113 is its ability to produce IAA, acetoin and siderophore [26].…”

Monocot diet sources drive diversity of gut bacterial communities in Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae

“…In this study, three OTUs from Protobacteria ( Pseudomonas , Acinetobacter , Pantoea ), two from Actinobacteria ( Microbacterium , Rhodococcus ) and one from Bacteroidetes ( Chryseobacterium ) were also identified. Similarly, Acinetobacter , Pantoea , Chryseobacterium , Rhodococcus , Microbacterium were previously reported to be associated with sugarcane, maize and onion plants in the field (Abadi et al, 2021; Calle‐Bellido et al, 2013; De Souza et al, 2016). These reports have further supported the submission that the reared S .…”

“…This could suggest that the FAW larvae must have ingested bacteria biota associated with the plant diets used in rearing them. For instance, Bacillus of phylum Firmicutes was detected on the sugarcane and maize diet groups and it has been reported to be associated with the sugar cane and maize leaves in the field (Abadi et al, 2021; De Souza et al, 2016).…”

Plants as a realized niche for Listeria monocytogenes

“…The rhizospheric microbiome is composed of various classes of microbes: fungi, bacteria and archaea, actinomycetes, protozoa, nematodes (Mendes et al, 2013), and algae (Lee & Ryu, 2021). Bacteria are a major component of the plant microbiome contributing to plant growth, protection from environmental stressors (Devarajan et al, 2021), protection from pathogens (Ritpitakphong et al, 2016) and they are essential to carbon and nitrogen cycles (Abadi et al, 2021; Reed et al, 2010). Phyllosphere microorganisms are mainly bacteria (Alphaproteobacteria, Gammaproteobacteria, and the phyla Bacteroidetes and Actinobacteria).…”