Plant growth promoting and antifungal activity in endophytic Bacillus strains from pearl millet (Pennisetum glaucum)

Abstract

Bacterial endophytes are well known inhabitants of living plant system and perform important assignments in maintaining plant growth and health. Currently, limited reports are available on the endophytes of pearl millet (Pennisetum glaucum) reflecting antagonistic and plant growth promoting (PGP) attributes. Therefore, the major objectives of current investigation were to identify antagonistic strains of endophytic Bacillus from pearl millet and further illustrate their PGP capabilities. In this study, 19 endophytic Bacillus strains (EPP5,

Isolation and Characterization of Root-Associated Bacterial Endophytes and Their Biocontrol Potential against Major Fungal Phytopathogens of Rice (Oryza sativa L.)

“…The findings of this study were supported by Kushwaha et al [24]. They described the PCR based amplification of antibiotic peptide related genes, including ItuD, BmyC, and srfA, from the 19 Bacillus endophytic bacterial strains with their biocontrol character in pearl millet cereal crop [24]. Moreover, Xu et al (2019) also published similar results related to functional biosynthesis antibiotic-related genes, such as PKSI, NRPS, ItuD, SrfC, and Sfp, by PCR from 33 different endophytic bacterial species, where 26 isolates from Bacillus ssp., showed antifungal activities against different phytopathogens of the mulberry plant respectively [25].…”

“…In the present study, after the amplification, we found that the majority of root-associated bacterial endophytes clearly displayed a positive indication regarding the 12 antibiotic-related genes. The findings of this study were supported by Kushwaha et al [24]. They described the PCR based amplification of antibiotic peptide related genes, including ItuD, BmyC, and srfA, from the 19 Bacillus endophytic bacterial strains with their biocontrol character in pearl millet cereal crop [24].…”

“…Similarly, in the present research, we also confirmed certain other biochemical and physiological parameters from bacterial endophytes, such as citrate activity, urease activity, nitrate reduction activity, Voges-Proskauer performance, methyl red activity, and starch hydrolyses activity, glucose activity, mannitol activity, the lactose activity, and maltose activity respectively (Table S2). These results were confirmed by a few studies in past years [24,42], both researchers demonstrated the comparative results of the many biochemical and physiological activities in the positive and negative conditions such as gelatinase production, nitrate reduction, Voges-Proskauer performance, citrate activity, and starch hydrolyses activity, etc., from various bacterial endophytes with similar kind of modes of action against plant pathogens in different crops, respectively [43]. In this regard, our study relates to the root-associated bacterial endophytes in-vitro conditions to investigate the dual-culture response against rice fungal pathogens, with promising roles as biocontrol agents for sustainable agriculture and a friendly ecosystem.…”

“…The classification of biochemical properties, including; gram reaction (GR), catalase activity (CA), endospore activity (EA), oxidase activity (OA), motility performance (MP), citrate activity (CA), and gelatinase production (GP) were detected from each of the root-associated bacterial endophytes followed by Kushwaha et al [24]. Determination of the physiological traits, such as; starch hydrolyses activity (SHA), nitrate reduction activity (NRA), Voges-Proskauer performance (VPP), methyl red activity (MRA), glucose activity (GA), mannitol activity (MA), lactose activity (LA), and maltose activity (MA) of all the bacterial endophytes were characterized by following Islam et al [42].…”

“…Moreover, the molecular screening of antibiotic encoding genes for particular endophytic bacteria, which are responsible for the number of antibiotics and antifungal metabolites production, including cyclic lipopeptides, bio-surfactin, 2, 4-di-acetyl phloroglucinols, pyoluteorin, phenazines, bacillomycins, fengycin, lipopeptides, pyrrolnitrin, celluloses, hydrogen cyanide, polyketide synthase, and non-ribosomal peptide synthases has been considered to be a valuable option for beneficial endophyte selection. These are the most promising bioactive compounds that are associated with biocontrol mechanisms against a wide range of bacterial and fungal phytopathogens [24,25]. The isolation and identification of these endophytic bacteria are essential for agricultural manipulations [26].…”