Assessment of endophytic yeast diversity in rice leaves by a culture-independent approach

Abstract

Endophytic microorganisms inhabit internal plant tissues in the host plant without causing any symptoms or negative effects. Although the diversity of endophytes has been evaluated by both culture-dependent and culture-independent methods, less information is available on yeast communities. Therefore, in this study a culture-independent method was used to examine endophytic yeasts associated with rice leaves based on the large subunit of ribosomal DNA using a semi-nested PCR technique. Sequence analysis indicated that the colonization frequency and the relative species frequency (RF) of endophytic yeast phylotypes were 0.41 and 0.06, respectively, and the majority of the yeast phylotypes were basidiomycetous yeasts. The phylotypes were designated as five known species (Cryptococcus victoriae, Debaryomyces hansenii, Debaryomyces vindobonensis, Meyerozyma guilliermondii and Pseudozyma antarctica), together with seventeen phylotypes closest to Candida metapsilosis, Cryp. foliicola, Cryp. laurentii, Pseudozyma abaconensis, Pseudozyma aphidis and Trichosporon asahii, among which some could be novel species. The most prevalent phylotypes were those closest to Cryp. foliicola (47.5 % RF) followed by D. hansenii (22.8 % RF) and P. antarctica (16.8 % RF). The presence of the phylotypes related to species known for their potential applications as biocontrol agents and plant growth promoting hormone producers suggests that they may have valuable applications. In addition, our findings revealed the occurrence of novel phylotypes at high frequency, which should encourage extensive studies to discover novel yeast species and to understand their roles in the rice leaves.

Community Analysis of Endophytic Bacteria from the Seeds of the Medicinal Plant Panax notoginseng

“…Chadha et al (2015) suggested that plant endophytic fungi can protect plants against various pathogen and pests and help plants survive under harsh biological or abiotic stresses. Tantirungkij et al (2015) reported that rice leaves harbor several new yeast strains. Khan et al (2015) isolated two fungal strains, Fusarium tricinctum RSF-4L and Alternaria alternata RSF-6L, which promote the growth of the host by phytohormone secretion.…”

Evidence for microbiome-dependent chilling tolerance in sorghum

“…We found that Vishniacozyma globispora, a basidiomycete yeast, was more abundant in early planting sorghum leaves. Vishniacozyma species have been identified as rice endophytes, Arctic plant endophytes, and tropical forest tree endophytes (Tantirungkij et al 2015, Santiago et al 2017, Felix et al 2020. Another close relative is a psychrotolerant yeast isolated from a glacier (Tsuji et al 2019).…”

Significant host‐ and environment‐dependent differentiation among highly sporadic fungal endophyte communities in cereal crops‐related wild grasses

“…The genus includes close to 20 identified species and many additional unclassified taxa, but only V . victoriae was previously reported as an endophyte, in Antarctic angiosperms Deschampsia antarctica and Colobanthus quitensis (Santiago et al ., 2017), and in rice leaves (Tantirungkij et al ., 2015). Vishniacozyma victoriae was highly prevalent in our data set, however we also found high occurrence of V. carnescens (former Torulopsis carnescens ), and several additional Vishniacozyma species that were present at lower levels.…”