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Morchella crassipes (Vent.) Pers., a typical yellow morel species with high economic value, is mainly distributed in the low altitude plains of Eurasia. However, rare research has been performed on its genomics and polarity, thus limiting its research and development. Here, we reported a fine physical map of the nuclear genome at the subchromosomal-scale and the complete mitochondrial genome of M. crassipes. The complete size of the nuclear genome was 56.7 Mb, and 23 scaffolds were assembled, with eight of them being complete chromosomes. A total of 11,565 encoding proteins were predicted. The divergence time analysis showed that M. crassipes representing yellow morels differentiated with black morels at ~33.98 Mya (million years), with 150 gene families contracted and expanded in M. crassipes versus the two black morels (M. snyderi and M. importuna). Furthermore, 409 CAZYme genes were annotated in M. crassipes, containing almost all plant cell wall degrading enzymes compared with the mycorrhizal fungi (truffles). Genomic annotation of mating type loci and amplification of the mating genes in the monospore population was conducted, the results indicated that M. crassipes is a heterothallic fungus. Additionally, a complete circular mitochondrial genome of M. crassipes was assembled, the size reached as large as 531,195 bp. It can be observed that the strikingly large size was the biggest up till now, coupled with 14 core conserved mitochondrial protein-coding genes, two rRNAs, 31 tRNAs, 51 introns, and 412 ncORFs. The total length of intron sequences accounted for 53.67% of the mitochondrial genome, with 19 introns having a length over 5 kb. Particularly, 221 of 412 ncORFs were distributed within 51 introns, and the total length of the ncORFs sequence accounted for 40.83% of the mitochondrial genome, and 297 ncORFs had expression activity in the mycelium stage, suggesting their potential functions in M. crassipes. Meanwhile, there was a high degree of repetition (51.31%) in the mitochondria of M. crassipes. Thus, the large number of introns, ncORFs and internal repeat sequences may contribute jointly to the largest fungal mitochondrial genome to date. The fine physical maps of nuclear genome and mitochondrial genome obtained in this study will open a new door for better understanding of the mysterious species of M. crassipes. [ABSTRACT FROM AUTHOR]

The transcriptome of Morchella crassipes M10 collected from Xinzheng of He'nan province was sequenced by the next generation sequencing technology, and distribution characteristic of simple sequence repeats (SSR) were analyzed. The results showed that: 1) A total of 13 044 SSR sites were detected, which was distributed in 8851 Trinity genes, about 2858 Trinity genes had more than one SSR loci and the number of compound formation SSR loci was 1925. The average density of SSR loci was 2067.77 bp/piece in the transcriptome sequence of Morchella crassipes, which was much higher than that of other fungi. 2) The number of single base repeat motif was 8600, the largest one, among which the number of A/T repeat types was higher than C/G repeat types and the same as most macro-fungi; the number of tri-nucleotide (TGC) repeat motif was 2497, among which ACC/GGT, AGC/CTG and AGG/CCT accounted for 60% and obviously appeared with GC high probability. In the development of SSR molecular marker or other repeat polymorphic marker, SSR abundant with GC could be chosen as the best primers. [ABSTRACT FROM AUTHOR]

A post-fire morel collected from Populus simonii stands in Mt. Qingling was identified as Morchella crassipes Mes-20 by using nuclear ribosomal DNA internal transcribed spacer phylogeny. It was inoculated into sweet corn to observe colonized roots in purified culture and in greenhouse experiments. The elongation and maturation zones of sweet corn were remarkably colonized at the cortex intercellular and intracellular cells, vessel cells, and around the Casparian strip, forming ectendomycorrhiza-like structures. Colonization was also observed in the zone of cell division proximal to the root cap. Greenhouse assays with sweet corn showed that this morel stimulated the development of the root system and significantly increased the dry root biomass. M. crassipes also significantly reduced the incidence of Fusarium verticillioides in the kernels of mature ears when inoculated into young ears before Fusarium inoculation and prevented Fusarium infection in corn ears compared with that of the control in the greenhouse. When grown under axenic conditions, M. crassipes produced the phytohormones abscisic acid, indole-3-acetic acid, and salicylic acid. The benefits to plants elicited by M. crassipes may result from these phytohormones which may improve the drought resistance, biomass growth and resistance to Fusarium. [ABSTRACT FROM AUTHOR]

The endophytic fungi in ascocarps of morchella crassipes from different sites were isolated and identified by morphological technology combined with sequence analysis of internal transcribed spacer (ITS) regions. The results indicated that the fungal endophytes in M. crassipes were diverse. From 3 sites 16 fungal strains belonging to 14 taxa were isolated and identified. Among which, 15 out of the 16 isolates were ascomycetes or their anamorphs, while only 1 isolate (Mortierella alpina) belonged to Zygomycota. Chaetomium fungi were isolated from samples of three origins and Lecanicillium fungicola var. aleophilum was isolated from sporocarps occurring in Mianyang, Sichuan province and Zhengzhou, Henan province, while the other isolates were specific for each sampling. [ABSTRACT FROM AUTHOR]

The interactions between bacteria and fungi, the main actors of the soil microbiome, remain poorly studied. Here, we show that the saprotrophic and ectomycorrhizal soil fungus Morchella crassipes acts as a bacterial farmer of Pseudomonas putida, which serves as a model soil bacterium. Farming by M. crassipes consists of bacterial dispersal, bacterial rearing with fungal exudates, as well as harvesting and translocation of bacterial carbon. The different phases were confirmed experimentally using cell counting and 13C probing. Common criteria met by other non-human farming systems are also valid for M. crassipes farming, including habitual planting, cultivation and harvesting. Specific traits include delocalization of food production and consumption and separation of roles in the colony (source versus sink areas), which are also found in human agriculture. Our study evidences a hitherto unknown mutualistic association in which bacteria gain through dispersal and rearing, while the fungus gains through the harvesting of an additional carbon source and increased stress resistance of the mycelium. This type of interaction between fungi and bacteria may play a key role in soils. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the fermentation optimization, molecular characterization, and antioxidant activity in vitro of exopolysaccharides (EPS) from Morchella crassipes in submerged culture. Firstly, an optimal medium for EPS production was obtained by single-factor experiment and central composite design as follows: maltose 44.79 g/L and tryptone 4.21 g/L. Then, one fraction of EPS was obtained from the culture filtrates by size exclusion chromatography and the molecular characteristics were examined by a multi-angle laser light scattering and refractive index detector system. The weight-average molar mass and the polydispersity ratio of the EPS fraction were revealed to be 1.961 × 10 g/mol and 1.838, respectively. FT-IR spectroscopy was used for obtaining vibrational spectra of the purified EPS fraction. Finally, the antioxidant activity of EPS was investigated and the relationship with molecular properties was discussed as well. [ABSTRACT FROM AUTHOR]

Cultural assays were used to compare the effect of various carbon (C) and nitrogen (N) sources on in vitro sclerotial formation and development, specifically in mycelial cultures of black and yellow morels ( Morchella elata and Morchella crassipes, respectively). While different C and N sources supported abundant mycelia growth, these nutritional parameters also influenced sclerotial formation. Carbon sources such as ribose, cellobiose, galactose, xylose, sucrose and mannitol produced many (18-125) large-sized (diameter 0.16-0.43 cm) and cream-colored sclerotia in M. crassipes; in M. elata, small-sized (diameter 0.16-0.28 cm) and brown-pigmented sclerotia were formed in media containing ribose, galactose, sorbose and mannitol. Among the nitrogen sources, sodium nitrate and yeast extract caused both morel species to produce significantly fewer sclerotia (6-24) of significantly smaller size (diameter 0.11-0.27 cm). Carbon sources such as mannitol and ribose and N sources, sodium nitrate and yeast extract produced numerous large-sized sclerotia in morels. [ABSTRACT FROM AUTHOR]

Morchella crassipes (Vent.) Pers., a typical yellow morel species with high economic value, is mainly distributed in the low altitude plains of Eurasia. However, rare research has been performed on its genomics and polarity, thus limiting its research and development. Here, we reported a fine physical map of the nuclear genome at the subchromosomal-scale and the complete mitochondrial genome of M. crassipes . The complete size of the nuclear genome was 56.7 Mb, and 23 scaffolds were assembled, with eight of them being complete chromosomes. A total of 11,565 encoding proteins were predicted. The divergence time analysis showed that M. crassipes representing yellow morels differentiated with black morels at ~33.98 Mya (million years), with 150 gene families contracted and expanded in M. crassipes versus the two black morels ( M. snyderi and M. importuna ). Furthermore, 409 CAZYme genes were annotated in M. crassipes , containing almost all plant cell wall degrading enzymes compared with the mycorrhizal fungi (truffles). Genomic annotation of mating type loci and amplification of the mating genes in the monospore population was conducted, the results indicated that M. crassipes is a heterothallic fungus. Additionally, a complete circular mitochondrial genome of M. crassipes was assembled, the size reached as large as 531,195 bp. It can be observed that the strikingly large size was the biggest up till now, coupled with 14 core conserved mitochondrial protein-coding genes, two rRNAs, 31 tRNAs, 51 introns, and 412 ncORFs. The total length of intron sequences accounted for 53.67% of the mitochondrial genome, with 19 introns having a length over 5 kb. Particularly, 221 of 412 ncORFs were distributed within 51 introns, and the total length of the ncORFs sequence accounted for 40.83% of the mitochondrial genome, and 297 ncORFs had expression activity in the mycelium stage, suggesting their potential functions in M. crassipes . Meanwhile, there was a high degree of repetition (51.31%) in the mitochondria of M. crassipes . Thus, the large number of introns, ncORFs and internal repeat sequences may contribute jointly to the largest fungal mitochondrial genome to date. The fine physical maps of nuclear genome and mitochondrial genome obtained in this study will open a new door for better understanding of the mysterious species of M. crassipes .