Plant growth-promoting properties of the phosphate-solubilizing red yeast Rhodosporidium paludigenum

Abstract

Phosphorus (P) is one of the essential elements that are necessary for plant development and growth. However, the availability of soluble forms of P for plants in the soils is limited, because a large proportion of it is bound to soil constituents. Thus, the concentration of P available to plants at any time is very low and, moreover, its availability depends on the soil pH. As a solution, phosphate-solubilizing microorganisms (PSMs) are employed that render inorganic P available to plants in soluble form. Thus far, research into PSMs has been insufficient, and only few such organisms have been considered for exploitation as microbial fertilizer strains. The characteristics of plant growth promotion with the plant-PSMs coculture system remain to be elucidated. In the current study, we report on the isolate Rhodosporidium paludigenum JYC100 that exhibits good performance for solubilizing calcium phosphate. We found that it can be regulated by the amount of soluble phosphate. Furthermore, R. paludigenum JYC100 promotes plant growth under specific conditions (P deficiency, but with insoluble phosphate) in different media and soil pots. In contrast, the yeast Aureobasidium pullulans JYC104 exhibited weak phosphate-solubilizing capacities and no plant growth-promoting ability. Compared to control plants, the biomass, shoot height, and cellular inorganic P content of plants increased in plants cocultivated with R. paludigenum JYC100. In addition, histochemical GUS and qRT-PCR assays of phosphate starvation-induced (PSI) genes showed that the transcript levels of these PSI genes are decreased in the plants cocultured with R. paludigenum JYC100. These findings reflect the unique ability of R. paludigenum JYC100 to convert insoluble P compounds to plant-available P, thereby leading to growth promotion. Our study results highlight the use of yeasts as potential substitutes for inorganic phosphate fertilizers to meet the P demands of plants, which may eventually improve yields in sustainable agricultures.

Mycobiota of Mexican Maize Landraces with Auxin-Producing Yeasts That Improve Plant Growth and Root Development

“…These sugars can be fermented by yeasts producing organic acids (e.g., citric acid) that dissolve inorganic phosphate, making it bioavailable in the rhizosphere [ 36 ]. Phosphate-solubilizing yeasts have increased the biomass, shoot height, and cellular inorganic phosphate content of plants growing under phosphate limitation [ 37 ]. Improved maize plant growth and phosphate nutrition have been observed in response to inoculation with a phosphate-solubilizing Candida railenensis , as well as synergism in phosphate uptake by arbuscular mycorrhizal fungi [ 38 ].…”

“…We observed the formation of root hairs on seedlings inoculated with yeast (3A). It is likely that the yeasts induced the cell cycle of the root stele, and consequently, more lateral roots were formed [ 37 ]. This modification of the root structure has been stimulated by other yeasts (e.g., Hannaella coprosmaensis , Ustilago esculenta , Sporidiobolus ruineniae , Pseudozyma aphidis , and Dothideomycetes sp.)…”

Plant-microbe interactions: mechanisms and applications for improving crop yield and quality

“…Noteworthy bacterial genera in this context include Azospirillum, Bacillus, Pseudomonas (Kirui et al, 2022), Streptomyces, and Nocardiopsis (Boubekri et al, 2021). Additionally, non-mycorrhizal fungi like Aspergillus, Alternaria, Fusarium, and Penicillium (Kalayu, 2019), as well as mycorrhizal fungi like Rhizophagus and Glomus (Zhang et al, 2018), and cyanobacteria genera like Anabaena and Westiellopsis (Yandigeri et al, 2011), and the yeast Rhodosporidium (Chen et al, 2023), are active phosphate-solubilizing representatives. The microorganisms recognized as highly efficient phosphate solubilizers include rhizobia species like R. leguminosarum, R. meliloti, M. mediterraneum, Bradyrhizobium sp., and B. japonicum (Fahde et al, 2023).…”