Isolation and Characterization of Plant Growth-Promoting Endophytic Bacteria Paenibacillus polymyxa SK1 from Lilium lancifolium

Abstract

Paenibacillus polymyxa is a plant growth-promoting rhizobacterium that has immense potential to be used as an environmentally friendly replacement of chemical fertilizers and pesticides. In the present study, Paenibacillus polymyxa SK1 was isolated from bulbs of Lilium lancifolium. The isolated endophytic strain showed antifungal activities against important plant pathogens like Botryosphaeria dothidea, Fusarium oxysporum, Botrytis cinerea, and Fusarium fujikuroi. The highest percentage of growth inhibition, i.e., 66.67 ± 2.23%, was observed for SK1 against Botryosphaeria dothidea followed by 61.19 ± 3.12%, 60.71 ± 3.53%, and 55.54 ± 2.89% against Botrytis cinerea, Fusarium fujikuroi, and Fusarium oxysporum, respectively. The metabolite profiling of ethyl acetate fraction was assessed through the UHPLC-LTQ-IT-MS/MS analysis, and putative identification was done with the aid of the GNPS molecular networking workflow. A total of 29 compounds were putatively identified which included dipeptides, tripeptides, cyclopeptides (cyclo-(Leu-Leu), cyclo(Pro-Phe)), 2-heptyl-3-hydroxy 4-quinolone, 6-oxocativic acid, anhydrobrazilic acid, 1-(5-methoxy-1H-indol-3-yl)-2-piperidin-1-ylethane-1,2-dione, octadecenoic acid, pyochelin, 15-hydroxy-5Z,8Z,11Z, 13E-eicosatetraenoic acid, (Z)-7-[(2R,3S)-3-[(2Z,5E)-Undeca-2,5-dienyl]oxiran-2-yl]hept-5-enoic acid, arginylasparagine, cholic acid, sphinganine, elaidic acid, gossypin, L-carnosine, tetrodotoxin, and ursodiol. The high antifungal activity of SK1 might be attributed to the presence of these bioactive compounds. The isolated strain SK1 showed plant growth-promoting traits such as the production of organic acids, ACC deaminase, indole-3-acetic acid (IAA), siderophores, nitrogen fixation, and phosphate solubilization. IAA production was strongly correlated with the application of exogenous tryptophan concentrations in the medium. Furthermore, inoculation of SK1 enhanced plant growth of two Lilium varieties, Tresor and White Heaven, under greenhouse condition. In the light of these findings, the P. polymyxa SK1 may be utilized as a source of plant growth promotion and disease control in sustainable agriculture.

Siderophore production by Bacillus subtilis MF497446 and Pseudomonas koreensis MG209738 and their efficacy in controlling Cephalosporium maydis in maize plant

“…Concerning the growth promotion parameters, results showed that grains inoculated with B. subtilis (T3) and grains inoculated with P. koreensis (T8) attained significant increase in fresh weight, dry weight, root length, shoot length, areal root, seminal root and stem diameter compared to control treatments in soil infested with C. maydis under greenhouse conditions (Table 3 ). These results reflect the role of the tested bioagent inoculants in their effects on growth parameters and control plants such as stimulating cell division, elongation, formation of dried tissues in plants and production of plant growth regulators (López-Reyes 2017 ; Shi et al 2018 ; Zhang et al 2019 ; Khan et al 2020 ). Similarly, Laslo et al (2012) reported that the rapid colonization of maize plant roots due to the production of siderophores by Pseudomonas strains stimulates plant growth and is often due to the reduction in the fungal population in the roots (Penyalver et al 2001 ).…”

Synthesis of nitrogenase by Paenibacillus sabinae T27 in presence of high levels of ammonia during anaerobic fermentation

“…Paenibacillus is a large genus of Gram-positive, facultative anaerobic, endospore-forming bacteria, and some diazotrophic Paenibacillus species and strains have been extensively used as the bacterial fertilizers in agriculture [16][17][18][19]. Paenibacilus polymyxa WLY78 is an extensively studied diazotroph that carries a minimal and compact nif cluster comprising nine genes (nifB nifH nifD nifK nifE nifN nifX hesA nifV) encoding Mo-nitrogenase.…”

Siderophore and indolic acid production by Paenibacillus triticisoli BJ-18 and their plant growth-promoting and antimicrobe abilities

“…The use of a siderophore to transport iron by chelation is vitally important for bacteria. Siderophores are low molecular weight compounds (500-1,500 Da) possessing a high affinity for Fe 3+ (K f > 10 30 ) (Haas & Defago, 2005) and they are synthesized by bacteria through non-ribosomal pathways (Hutchins et al, 1999;Khan et al, 2020). Many PGPB have been reported to produce siderophores, such as Bacillus subtilis, Paenibacillus polymyxa SK1, Mesorhizobium sp., Brevibacillus brevis GZDF3 (Franco-Sierra et al, 2020;Khan et al, 2020;Menéndez et al, 2020;Sheng et al, 2020).…”

“…Siderophores are low molecular weight compounds (500-1,500 Da) possessing a high affinity for Fe 3+ (K f > 10 30 ) (Haas & Defago, 2005) and they are synthesized by bacteria through non-ribosomal pathways (Hutchins et al, 1999;Khan et al, 2020). Many PGPB have been reported to produce siderophores, such as Bacillus subtilis, Paenibacillus polymyxa SK1, Mesorhizobium sp., Brevibacillus brevis GZDF3 (Franco-Sierra et al, 2020;Khan et al, 2020;Menéndez et al, 2020;Sheng et al, 2020). The chelate of siderophores and ferric iron can be directly absorbed by plants and are called mechanism III, which is thought to be used by plants to resist iron stress (Shenker et al, 1992;Yehuda et al, 1996;Chen, Dick & Streeter, 2000).…”