Rhizosphere yeast Torulaspora globosa with plant growth promotion traits and improvement of the development of tomato seedlings under greenhouse conditions

Abstract

Yeasts are an interesting group of microorganisms, which occur naturally in soil and on plant surfaces. Few studies have analysed their potential as plant growth promoters. Thus, the aim of this study was to evaluate the indole acetic acid (IAA) production and phosphate solubilization by the yeasts Torulaspora globosa (CCA5S51 and CCA5S55), Meyerozyma guilliermondii (CCA3C98), and Rhodotorula mucilaginosa (CCA2F32), and the influence of T. globosa (CCA5S55) in the development of tomato seedlings. The results showed that T. globosa strains present both plant growth promotion traits (IAA production and phosphate solubilization). The strains of T. globosa (5S51 and 5S55) showed high IAA production (641 and 669 µg.ml-1, respectively) after 48 h of incubation, while Rh. mucilaginosa produced 406 µg.ml-1 of IAA after 120 h. The strains CCA5S55 and CCA5S51 could also solubilize 47 and 35% of tricalcium phosphate in the medium, respectively, after 12 days of incubation; whereas M. guilliermondii (CCA3C98) solubilized only 10% of the tricalcium phosphate after 12 days. The inoculation of tomato seedlings with T. globosa stimulates the plant growth; root height was statistically superior when the higher cell concentration was inoculated. The root dry weight was enhanced with addition of glucose and tryptophan. The conclusion is the yeast species T. globosa is able to produce IAA in the presence of tryptophan and also solubilize phosphate in vitro. The inoculation of tomato seedlings promoted its development. The cell concentration and the addition of glucose and tryptophan must be evaluated in details to attain optimized yields.

Unlocking the plant growth-promoting potential of yeast spp.: exploring species from the Moroccan extremophilic environment for enhanced plant growth and sustainable farming

“…Whether applied individually or in combination, these yeast species have significantly improved both shoot/root dry weight and number of leaves. Moreover, our research has revealed that these extremophilic yeasts possess the ability to enhance nutrient uptake, as evidenced by their increased assimilation of essential nutrients such as N, P, and K. Numerous studies have also substantiated the capacity of yeast strains to promote the growth of Oryza sativa, Solanum lycopersicum , and Nicotiana benthamiana (Amprayn et al 2012 , Thais et al 2019 , Fernandez-San Millan et al 2020 , Tapia-Vázquez et al 2020 ). Fernandez-San Millan et al ( 2020 ) demonstrated the effectiveness of applying R. dairenensis in enhancing the growth and development of Nicotiana benthamiana .…”

Levaduras aisladas de biofermentos de microorganismos de montaña, una opción para la nutrición vegetal

“…Some studies that show this potential improvement was presented by Liu et al (2016) who managed to improve IAA production by working with Saccharomyces sp. and Torulaspora globosa in YPD media with tryptophan (0.1 % w / v), finding an increase in IAA concentration from 13 mg L -1 to 287 mg L -1 ; and Thais et al (2019) that studied the synthesis of IAA with Torulaspora globosa in supplemented PD media, obtaining a maximum concentration of 669 mg L -1 , values that would have to be carefully analyzed to avoid reaching toxic levels of IAA.…”