Identification and functional studies of microbial volatile organic compounds produced by Arctic flower yeasts

Abstract

Microbial volatile organic compounds (mVOCs) can serve as a communication channel among microorganisms, insects and plants, making them important in ecosystem. In order to understand the possible role of mVOCs in Arctic ecology, the microbes in Arctic flowers and their mVOCs and effects on plants were investigated. This study aims to isolate different yeast species from the flowers of five Arctic plant species and further to explore the function of mVOCs emitted by these microbes to plant. It was found that the composition and amount of mVOCs produced by the isolated yeasts were considerably affected by changes in incubation temperature. When the incubation temperature rose, the species of alcohols, aldehydes, esters, organic acids, and ketones increased, but substances specific to low temperature decreased or disappeared. When yeasts were co-cultured with Arabidopsis thaliana without any direct contact, mVOCs produced by the isolated yeasts inhibited the seed germination of A. thaliana at low temperatures; however, the mVOCs promoted the chlorophyll content, fresh weight, root weight and flowering rate of Arabidopsis plants. Although the overall growth-promoting effect of yeast mVOCs was higher at 20°C than at 10°C, the growth-promoting effect on roots, flowers and chlorophyll was highest at 10°C. When cultured at 10°C, the mVOCs produced by Cystofilobasidium capitatum A37, Cryptococcus sp. D41, and Sporidiobolus salmonicolor D27 had the highest growth-promoting effects on the root, flowering rate and chlorophyll content of Arabidopsis, respectively. In the co-culture system, some new mVOCs were detected, such as hendecane, tetradecane, and 1-hexanol that have been proven to promote plant growth. In addition, mVOCs of the isolated Arctic yeasts could inhibit the growth of several microorganisms, especially filamentous fungi. It was the first time to prove that mVOCs produced by the isolated yeasts had varying effects on plant growth at different incubating temperatures, providing a reference for the interactions between microorganisms and plants and their possible responses to climate change in the Arctic area. Moreover, the characteristics of promoting plant growth and inhibiting microbial growth by mVOCs of Arctic yeasts would lay a foundation for potential applications in the future.

<em>Solicoccozyma aeria</em> YCPUC79 Promotes Tomato Seedling Root Growth by Volatile Organic Compounds Emission

“…As mentioned in the introduction, several yeast strains have been studied due to their capacity to release VOCs with plant fungal disease control capacity [12][13][14][15] which results in better plant growth when applied to crops. The only report we found dealing with the stimulatory effect of VOCs released by yeasts details the compounds released by yeasts isolated from flowers of arctic plants [16]. Here we present evidence that S. aeria YCPUC79, a yeast strain isolated from soils of semi-arid regions, stimulates the production of lateral roots in tomato seedlings due to the synthesis and release of several VOCs.…”

“…With regards to yeasts, some authors have reported that Wickerhamomyces anomalus, Metschnikowia pulcherrima, Aureobasidium pullulans, Saccharomyces cerevisiae, Pichia kudriavzevii, P. occidentalis, Meyerozyma quilliermondii and Aureobasidium pullulans release VOCs with the capacity to control fungal diseases that affect crops or produce during postharvest [12][13][14][15]. Few reports deal with yeasts synthesizing VOCs with plant growth promotion, including a study with yeasts isolated from arctic plants that promote plant growth on Arabidopsis thaliana [16] or a study with A. pullulans promoting plant growth in beans and soybean [13]. In the last case, it is not clear if the plant growth promotion effect is due to VOCs or other compounds released by the yeast.…”

Microbial Allies in Agriculture: Harnessing Plant Growth-Promoting Microorganisms as Guardians against Biotic and Abiotic Stresses

“…Microbial volatiles help break seed dormancy, increase seed propagation, seedling vigor, root size, and leaf surface area, as well as enhance photosynthetic efficacy and plant output. Additionally, microbial volatiles promotes systemic tolerance to abiotic stressors and strengthen the plant's defenses against diseases and pests with various regimes [158][159][160]. The roles of microbial volatiles are described as follows:…”

A quantitative survey of the blueberry (Vacciniumspp.) nectar microbiome: variation between cultivars, locations, and farm management approaches

“…In the last 20 years, research describing the nectar microbiome has intensified: flowers across the globe have been surveyed, from the tropics (Canto and Herrera 2012) to the Artic (Niu et al 2023). Although most studies have focused on natural habitats, some have also examined the nectar microbiome within agroecosystems, predominantly in orchards.…”