Aspergillus tubingensis and Talaromyces islandicus Solubilize Rock Phosphate Under Saline and Fungicide Stress and Improve Zea mays Growth and Phosphorus Nutrition

Abstract

The purpose of this study was to evaluate the capability of Aspergillus tubingensis and Talaromyces islandicus to solubilize inorganic phosphorus sources, their activity under abiotic stress, and the enhancement of P availability in soils and plant growth. The P-solubilizing capability and acidification mechanism of the strains were assessed in vitro using tricalcium phosphate and rock phosphate. Independent assays were conducted with rock phosphate under NaCl and fungicides carbendazim, chlorothalonil, and propamocarb hydrochloride using a factorial design. Thereafter, the effects of fungal inoculations in rock phosphate-amended soil and P nutrition of Zea mays were assessed in a greenhouse experiment. Both fungi solubilized P in vitro via acidification through the exudation of acetic, citric, lactic, malic, quinic, and succinic acids. The P-solubilizing efficiency of A. tubingensis was maintained above 97.5% under 0.5 to 3.0% NaCl, up to 28.7% in the treatment with carbendazim, up to 5.3% with chlorothalonil, and above 96.5% with propamocarb hydrochloride; while T. islandicus efficiency decreased to 45.2% in a NaCl concentration-dependent trend, and maintained it above 80% in the fungicide treatments. The inoculation with A. tubingensis increased the available P in the amended soil by up to 65% after 30 days and resulted in 87% higher foliar P content, 111% greater plant height, and 25% greater dry weight of maize shoots. Similarly, T. islandicus contributed to these parameters in 55, 67, 90, and 17%, respectively. These findings suggest their potential as qualified phosphorus solubilizing microorganisms to develop novel and sustainable approaches for P fertilization in agriculture.

Effect of Repeated Plant Debris Reutilization as Organic Amendment on Greenhouse Soil Fertility

“…Different studies have observed the ability of fungal organisms to solubilize phosphorus ( Alternaria spp., Aspergillus spp., Penicillium spp., Trichoderma spp., Rhizopus spp.) [ 74 , 75 , 76 ], participate in nitrification processes ( Aspergillus spp., Penicillium spp.) [ 77 ], promote plant growth ( Trichoderma spp.)…”

Remediation of Pb-contaminated soil using biochar-based slow-release P fertilizer and biomonitoring employing bioindicators

“…Subsequently, it was washed with distilled water, dried at 60 °C and then stored. The bioavailable P content was determined with the Olsen method (Olsen-P) 12 , 44 . In brief, 1.0 g of solid with 20 ml of 0.5 M NaHCO 3 solution (pH 8.5) was shaken (100 rpm) for 30 min, then the solid was removed by filtration (0.45 µm).…”

Cellulolytic fungi modify the nitrogen, phosphorus, and potassium contents of organic fertilizers

“…These results indicated that all CF isolates could mineralize P from organic fertilizers as their additional character. The ability of some CF species belonging to the genera Talaromyces, Penicillium, and Purpureocillium as P solubilizers have been reported [42][43][44]. The two main mechanisms involved in P solubilization by microorganisms are the synthesis of phosphatase and phytase enzymes [45][46][47][48] and the release of organic acids such as oxalic, citric, acetic, succinic, and lactic [48][49][50][51] during the decomposition process.…”