AUTHOR=Suraby Erinjery Jose , Agisha Valiya Nadakkakath , Dhandapani Savitha , Sng Yee Hwui , Lim Shi Hui , Naqvi Naweed I. , Sarojam Rajani , Yin Zhongchao , Park Bong Soo 

TITLE=Plant growth promotion under phosphate deficiency and improved phosphate acquisition by new fungal strain, Penicillium olsonii TLL1

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1285574

DOI=10.3389/fmicb.2023.1285574

ISSN=1664-302X

ABSTRACT=<p>Microbiomes in soil ecosystems play a significant role in solubilizing insoluble inorganic and organic phosphate sources with low availability and mobility in the soil. They transfer the phosphate ion to plants, thereby promoting plant growth. In this study, we isolated an unidentified fungal strain, POT1 (<italic>Penicillium olsonii</italic> TLL1) from indoor dust samples, and confirmed its ability to promote root growth, especially under phosphate deficiency, as well as solubilizing activity for insoluble phosphates such as AlPO<sub>4</sub>, FePO<sub>4</sub>·4H<sub>2</sub>O, Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>, and hydroxyapatite. Indeed, in vermiculite containing low and insoluble phosphate, the shoot fresh weight of Arabidopsis and leafy vegetables increased by 2-fold and 3-fold, respectively, with POT1 inoculation. We also conducted tests on crops in Singapore’s local soil, which contains highly insoluble phosphate. We confirmed that with POT1, Bok Choy showed a 2-fold increase in shoot fresh weight, and Rice displayed a 2-fold increase in grain yield. Furthermore, we demonstrated that plant growth promotion and phosphate solubilizing activity of POT1 were more effective than those of four different <italic>Penicillium</italic> strains such as <italic>Penicillium bilaiae</italic>, <italic>Penicillium chrysogenum</italic>, <italic>Penicillium janthinellum</italic>, and <italic>Penicillium simplicissimum</italic> under phosphate-limiting conditions. Our findings uncover a new fungal strain, provide a better understanding of symbiotic plant-fungal interactions, and suggest the potential use of POT1 as a biofertilizer to improve phosphate uptake and use efficiency in phosphate-limiting conditions.</p>