Plant growth‐promoting rhizobacteria isolation from rhizosphere of submerged macrophytes and their growth‐promoting effect onVallisneria natansunder high sediment organic matter load

Abstract

Summary Sediment organic matter is a key stressor for submerged macrophyte growth, which negatively impacts the ecological restoration of lakes. Plant growth‐promoting rhizobacteria (PGPR) were screened from the rhizosphere of submerged macrophytes and used due to their promoting effect on Vallisneria natans under a high sediment organic matter load. Root exudates were used as the sole carbon source to obtain the root affinity strains. Eight isolates were selected from the 61 isolated strains, based on the P solubilization, IAA production, cytokinins production and ACC deaminase activity. The analysis of the 16S rDNA indicated that one strain was Staphylococcus sp., while the other seven bacterial strains were Bacillus sp. They were all listed in low‐risk groups for safety use in agricultural practices. The plant height significantly increased after inoculation with PGPR strains, with the highest rate of increase reaching 96%. This study provides an innovative technique for recovering submerged macrophytes under sediment organic matter stress.

Shifts in the rhizobiome during consecutive in planta enrichment for phosphate‐solubilizing bacteria differentially affect maize P status

“…In future research, adaptations to these parameters could be included. For example, the addition of well‐known root exudates to mimic the presence of a plant might influence a consortium’s P‐solubilizing capacity (Wang e t al ., 2021). Taking abovementioned observations into account, the in vitro evaluation of P‐solubilization by the bacterial consortia obtained via the consecutive enrichments in our platform confirmed the shortcomings encountered in other in vitro studies aiming at selecting biostimulatory bacterial strains (Chauhan et al ., 2015; Souza et al ., 2015).…”

“…All re-isolated strains were consistently more active in colonizing seedlings. Wang et al (2021) performed an in vitro screening for PGPR on selective medium in which root exudates were used as a sole carbon source as an alternative method to select for rhizosphere competent microorganisms. Finally, community-based culture collections (CBC) are a new strategy for selecting microbial isolates or consortia with a high potential to colonize different plant parts.…”

The Contrivance of Plant Growth Promoting Microbes to Mitigate Climate Change Impact in Agriculture

“…This can occur through several mechanisms, including altered hormone production by the plant, increased nutrient uptake, lowering water stress, maintainance of favourable K + /Na + ratio or osmotic adjustment ( Table 1 ) [ 52 , 67 , 123 ]. Several genera are involved in the successful control of salinity stress in crops, such as Bacillus , Pseudomonas , Agrobacterium , Streptomyces or Ochromobacter [ 52 , 105 , 147 , 148 ]. Many studies have been conducted to verify the prevalence of salinity-tolerant strains.…”

“…Less access to water increases the concentration of ions. Both water scarcity and high salinity can create hypertonic conditions, leading to osmotic stress, thus disturbing the nutrient and water balance, the permeability of membranes and and reducing the activity of selected enzymes [ 147 ]. Drought tolerance is usually the result of many biochemical and physiological adaptations, which consequently allow the plant to maintain its desired size and yield despite unfavorable environmental conditions.…”

A comparison of bacterial variability across biogeographic regions based on PGPR

“…Rehabilitating macrophyte species and communities is more challenging than rehabilitating terrestrial plants. Aquatic The PGPR strains can enhance the recovery of submerged plants in organically rich sediment [55]. In many parts of the world, water ecosystems are experiencing deterioration in water quality and ecological structure [56].After a decrease in water nutrition level, macrophytes usually take decades to adjust to the new environment [57].…”