Role of Rahnella aquatilis AZO16M2 in Phosphate Solubilization and Ex Vitro Acclimatization of Musa acuminata var. Valery

Abstract

Rahnella aquatilis AZO16M2, was characterized for its phosphate solubilization capacity to improve the establishment and survival of Musa acuminata var. Valery seedlings under ex-acclimation. Three phosphorus sources (Rock Phosphate (RF), Ca3(PO4)2 and K2HPO4) and two types of substrate (sand:vermiculite (1:1) and Premix N°8) were selected. The factorial analysis of variance (p < 0.05) showed that R. aquatilis AZO16M2 (OQ256130) solubilizes Ca3(PO4)2 in solid medium, with a Solubilization Index (SI) of 3.77 at 28 °C (pH 6.8). In liquid medium, it was observed that R. aquatilis produced 29.6 mg/L soluble P (pH 4.4), and synthesized organic acids (oxalic, D-gluconic, 2-ketogluconic and malic), Indole Acetic Acid (IAA) (33.90 ppm) and siderophores (+). Additionally, acid and alkaline phosphatases (2.59 and 2.56 µg pNP/mL/min) were detected. The presence of the pyrroloquinoline-quinone (PQQ) cofactor gene was confirmed. After inoculating AZO16M2 to M. acuminata in sand:vermiculite with RF, the chlorophyll content was 42.38 SPAD (Soil Plant Analysis Development). Aerial fresh weight (AFW), aerial dry weight (ADW) and root dry weight (RDW) were superior to the control by 64.15%, 60.53% and 43.48%, respectively. In Premix N°8 with RF and R. aquatilis, 8.91% longer roots were obtained, with 35.58% and 18.76% more AFW and RFW compared with the control as well as 94.45 SPAD. With Ca3(PO4)2, values exceeded the control by 14.15% RFW, with 45.45 SPAD. Rahnella aquatilis AZO16M2 favored the ex-climatization of M. acuminata through improving seedling establishment and survival.

Properties of Potential Plant-Growth-Promoting Bacteria and Their Effect on Wheat Growth Promotion (Triticum aestivum) and Soil Characteristics

“…Rahnella aquatilis is the species most often described in relation to plants, but Rahnella aceris is very similar to this species [32]. For Rahnella aceris, the properties of plant protection from pathogens [33] and phosphate-solubilizing activity [34] have been described.…”

Biological Control of Pepper Soft Rot Disease Caused by Pectobacterium carotovorum Using Rahnella aquatilis

“…Furthermore, R. aquatilis AZO16M2, was characterized for its phosphate solubilization capacity to improve the establishment and survival of Musa acuminata var. Valery seedlings under ex vitro-acclimation (Landa-Acuña et al, 2023). Additionally, Abdel-Latif et al ( 2021) stated that the inoculation of plants with PGPR Bacillus subtilis improved the growth of salt-stressed barley plants primarily by preserving the integrity of the cellular membranes, elevating nitrate reductase and glutamine synthetase activities, and providing the cultures with the growth hormone indole-3-acetic acid/indole acetic acid (IAA).…”

“…R. aquatilis is considered to have great potential as an antagonist to many bacterial pathogens (Laux et al, 2002;El-Hendawy et al, 2003;Chen et al, 2007Chen et al, , 2009Li et al, 2020a). Also, plant growth promotion by R. aquatilis has been reported (Yuan et al, 2020;Li et al, 2021;Kong et al, 2022;Landa-Acuña et al, 2023). Rahnella aquatilis strains 17 and 55 has been previously reported as potential biological control agents of bacterial spots of tomato caused by Xanthomonas campestris pv.…”

Editorial for “Special Abilities of Microbes and Their Application in Agro-Biology”

“…Valery using Rahnella aquatilis AZO16M2 was also evident when using microbes as a PGPR. In a solid medium with Ca 3 (PO 4 ) 2 , R. aquatilis AZO16M2 exhibited a solubilization index (SI) of 3.77 at 28 °C, and in a liquid medium, it produced 29.6 mg/L of soluble P at a pH of 4.4 [ 8 ].…”