Formulation of bacterial consortia from avocado (Persea americana Mill.) and their effect on growth, biomass and superoxide dismutase activity of wheat seedlings under salt stress

Abstract

Inoculation of plants with bacteria that produce indole acetic acid (IAA) and 1aminocyclopropane-1-carboxylate deaminase (ACCD) often has a positive effect on alleviation of salt stress in plants. Here, we isolated, characterized and formulated halotolerant bacterial consortia from avocado trees with the aim of developing biofertilizers to improve avocado production on saline soils.Using wheat as a test plant, experiments were conducted to investigate the effects of selected bacterial consortia on growth, biomass and superoxide dismutase (SOD) activity of wheat seedlings exposed to salt stress (0.25 M and 0.45 M NaCl) under greenhouse conditions. Among 309 isolates, 17.4% were characterized as halotolerant IAA-and ACCD-producing bacteria. Based on differences in their IAA production and ACCD activities, four consortia were formulated using members of five genera: Enterobacter,Serratia,Microbacterium, Pseudomonas andAchromobacter. Inoculation with selected halotolerant bacterial consortia significantly (P≥0.05) increased the emergence, growth, biomass and SOD activity of wheat seedlings exposed to salt stress. Avocado trees and their rhizosphere soils harbor halotolerant IAA-and ACCD-producing bacteria with the potential to mitigate the salt stress effects on plants. While wheat was useful for screening, further studies are necessary to validate the effects of selected bacterial consortia on avocado growth and yields under saline conditions.

Assessment of plant growth promoting activities and abiotic stress tolerance of Azotobacter chroococcum strains for a potential use in sustainable agriculture

“…This hormone is an important growth enhancer since it is the most efficient among auxins with a significant effect on plant root system development (Sharma et al, 2015). Recently, Barra et al (2016) confirmed the importance of rhizocompetent stress tolerant bacterial strains with variable activity of the ACCd and production of the IAA for the alleviation of salt stress in plants.…”

Effect of rhizobacterial consortia from undisturbed arid- and agro-ecosystems on wheat growth under different conditions

“…Interestingly, addition of inocula from arid ecosystems (C1) also resulted in higher biomass compared with uninoculated control, but not statistically significant. The biomass-promoting effect of the C2 might be related to their higher auxin production and ACCD activity, as observed by Jorquera et al (2014) and Barra et al (2016) for isolates strains from agroecosystems compared with isolates strains from arid ecosystems. In addition, the strains of C1 were isolated from arid ecosystems with low nutrient availability (e.g.…”

“…() and Barra et al . () for isolates strains from agro‐ecosystems compared with isolates strains from arid ecosystems. In addition, the strains of C1 were isolated from arid ecosystems with low nutrient availability (e.g.…”

“…; Barra et al . ); but, their effect on plant biomass had not been assayed so far. A second rhizobacterial consortium from agro‐ecosystems (C2) was formed with the strains Bacillus sp.…”

Beneficial microbiomes: Biodiversity and potential biotechnological applications for sustainable agriculture and human health

“…SBP-8 Salinity stress Plant growth and yield [87] Lysinibacillus fusiformis IARI-THD-4 Acidic stress Growth and yield [15] Micrococcus roseus SW1 Acidic stress Growth and yield [88] Paenibacillus polymyxa BNH18 Cold stress Growth, alleviate cold [81] Paenibacillus xylanexedens BNW24 Alkalinity stress Growth and alleviate alkalinity [81] Pantoea intestinalis DSM 28113 T Drought and heat stress Alleviate drought stress [89] Piriformospora indica (Pi) Drought and heat stress Drought resistance, growth [90] Planococcus salinarum BSH13 Acidic stress Growth and alleviate acidity [81] Pseudomonas fluorescens 153 Salinity stress Salinity stress, growth [91] Pseudomonas lurida M 2 RH 3 Cold stress Growth and nutrient uptake [92] Pseudomonas poae IARI-NIAW2-1 Drought and heat stress Growth, yield [13] Pseudomonas putida AKMP7 Drought and heat stress Growth, alleviate heat stress [93] Pseudomonas putida 108 Salinity stress Salinity stress, growth [91] Pseudomonas rhizosphaerae IARI-DV-26 Alkalinity stress Growth and alleviation [81] Pseudomonas sp. NARs 9 Cold stress Germination, shoot, root lengths [94] Rhodobacter sphaeroides IARI-NIAW1-7 Drought and heat stress Growth, yield [13] Serratia marcescens 73 Salinity stress Growth and SOD activity [73] Sporosarcina sp. BNH20 Cold stress Growth, alleviate cold [81] Staphylococcus arlettae BNW27 Alkalinity stress Growth and alleviate alkalinity [81] Staphylococcus epidermidis IARI-THW-28 Acidic stress Growth and yield [15] as one of the most efficient and eco-friendly sustainable methods for increasing the growth and yield of crop plants.…”