The plant growth‐promoting potential of the mesophilic wood‐rot mushroomPleurotus pulmonarius

Abstract

Aims To demonstrate the plant growth‐promoting potential of a wood‐decay mushroom. Methods and Results A wild strain of a white rot fungus (Pleurotus pulmonarius) was found to convert 10 mmol l−1 L‐tryptophan (TRP) to approximately 15 μg ml−1 indole‐3‐acetic acid (IAA) under the optimal growth conditions of 30°C and pH 5 for 15 days. Results of gas chromatography–mass spectrometry indicated IAA synthesis through the indole‐3‐pyruvic acid pathway when using cellulose as a sole carbon source. The mycelium as well as the culture filtrate promoted the growth and chlorophyll content of seedlings. In a monocotyledonous plant (rice), the number of lateral roots was increased experimentally, whereas in a dicotyledonous plant (tomato), the fungus led to an increased length of shoots and roots. Conclusions TRP‐dependent IAA production was demonstrated for the first time for P. pulmonarius and may be responsible for enhancing plant growth in vitro. Significance and Impact of the Study Synthesis of IAA as the most prevalent phytohormone in plants has been demonstrated for soil microfungi. Pleurotus pulmonarius is reported as an IAA‐producing wood‐decay macrofungus. The higher temperature optimum of P. pulmonarius isolated from subtropical environment compared to other Pleurotus species from temperate regions makes it more suitable for application in subtropical/tropical regions.

Fungal pretreatment of lignocellulosic biomass for the production of plant hormone by Pichia fermentans under submerged conditions

“…The fungi produced maximum auxin on the 18th day (76 µg/ml) (Ünyayar et al 2000), while the same strain Phanerochaete chrysosporium ME446 demonstrated 0.198 µg IAA/ml in broth medium (Ünyayar 2002). Recently, another wood-degrading basidiomycetes Pleurotus pulmonarius was reported to convert 10 mM tryptophan to approximately 15 μg/ml IAA using, cellulose as a sole carbon source (Pham et al 2019). Three white rot fungi Pleurotus ostreatus, Phanerochaete chrysosporium and Trametes versicolor produced IAA when plant biomass (Jatropha seed cake) was used as a substrate.…”

Ligninase Profiling and Optimization of Laccase Production from Indigenous Wood Rot Fungus (WRF) KLUM2 in Kirk Medium-Alkali Lignin Kayu Jati (MK-ALKJ)

“…Ligninase production by wood-rotting fungi is also influenced by growth conditions such as temperature and pH. WRF isolates classified as mesophyll fungi can live in a temperature range of 15-40 °C (Pham et al, 2019). The optimum pH for the production of heme peroxidase is at pH of 4.5-5.5 (Acevedo et al, 2011), and for the production of phenol oxidase (laccase) is between pH of 3-7 (Hamid et al, 2013).…”