Research Article |
Corresponding author: Gang Tao ( tg0729@163.com ) Corresponding author: Francis M. Martin ( francis.martin@inrae.fr ) Academic editor: Michael Bradshaw
© 2025 Gang Tao, Steven Ahrendt, Shingo Miyauchi, XiaoJie Zhu, Hao Peng, Kurt Labutti, Alicia Clum, Richard Hayes, Patrick S. G. Chain, Igor V. Grigoriev, Gregory Bonito, Francis M. Martin.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tao G, Ahrendt S, Miyauchi S, Zhu XJ, Peng H, Labutti K, Clum A, Hayes R, Chain PSG, Grigoriev IV, Bonito G, Martin FM (2025) Characterisation and comparative analysis of mitochondrial genomes of false, yellow, black and blushing morels provide insights on their structure and evolution. IMA Fungus 16: e138363. https://doi.org/10.3897/imafungus.16.138363
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Morchella species have considerable significance in terrestrial ecosystems, exhibiting a range of ecological lifestyles along the saprotrophism-to-symbiosis continuum. However, the mitochondrial genomes of these ascomycetous fungi have not been thoroughly studied, thereby impeding a comprehensive understanding of their genetic makeup and ecological role. In this study, we analysed the mitogenomes of 30 Morchellaceae species, including yellow, black, blushing and false morels. These mitogenomes are either circular or linear DNA molecules with lengths ranging from 217 to 565 kbp and GC content ranging from 38% to 48%. Fifteen core protein-coding genes, 28–37 tRNA genes and 3–8 rRNA genes were identified in these Morchellaceae mitogenomes. The gene order demonstrated a high level of conservation, with the cox1 gene consistently positioned adjacent to the rnS gene and cob gene flanked by apt genes. Some exceptions were observed, such as the rearrangement of atp6 and rps3 in Morchella importuna and the reversed order of atp6 and atp8 in certain morel mitogenomes. However, the arrangement of the tRNA genes remains conserved. We additionally investigated the distribution and phylogeny of homing endonuclease genes (HEGs) of the LAGLIDADG (LAGs) and GIY-YIG (GIYs) families. A total of 925 LAG and GIY sequences were detected, with individual species containing 19–48HEGs. These HEGs were primarily located in the cox1, cob, cox2 and nad5 introns and their presence and distribution displayed significant diversity amongst morel species. These elements significantly contribute to shaping their mitogenome diversity. Overall, this study provides novel insights into the phylogeny and evolution of the Morchellaceae.
Genomic synteny, homing endonuclease gene, mitochondrial genome, Morchella, protein-coding gene
Mitochondria are semi-autonomous organelles that play a pivotal role in fungal respiratory metabolism and energy production (
The evolutionary history of fungal mitogenomes warrants further investigation, particularly considering their high variability in size and gene arrangement. Previous studies have reported diverse genome sizes, ranging from 11.2 kb (Hanseniaspora pseudoguilliermondii) to 332.2 kb (Golovinomyces cichoracearum), which have primarily been attributed to differences in intergenic regions, intron number and intronic ORFs (
The presence of repeated DNA sequences, such as introns that display self-splicing and insertion endonuclease activity, can significantly impact the structural dynamics of fungal mitochondrial genomes. This can result in variations in gene order, dispersion of repetitive elements and introduction of new genes through horizontal gene transfer (HGT) (Ferandon et al. 1995;
Homing endonuclease genes (HEGs) are commonly located within the introns of fungal mitogenomes and are distributed amongst the cox, cob, nad and rRNA genes (
Morels belong to the Morchella genus (Ascomycota Morchellaceae). Although only 59 are formally recognised as valid Latin binomials (
In this study, we sequenced, annotated and characterised the mitogenomes of 30 Morchellaceae species that encompass a range of phylogenetic lineages (false morels, blushingmorels, black morels and yellow morels) and ecological types. Our objectives were: to elucidate the genetic characteristics of these mitogenomes; compare the phylogeny based on the core PCGs with the nuclear genome phylogeny; analyse the composition, distribution and synteny of PCGs and HEGs; and gain insight into the phylogenetic features and potential impact of lifestyle. This study constitutes the first comprehensive investigation of the mitogenomes of Morchellaceae and provides valuable information on the phylogeny, genomics and ecological roles of this significant fungal group.
Thirty fungal strains, including 28 Morchella species and two false morels (Disciotis venosa NRRL24433 and Verpa conica TJ0815), were collected from specific locations (Table
General statistics and taxonomic information for the 30 species. mtDNA size, mitochondrial genome size; No. scf, the number of scaffold; 1. No. t RNA: number of tRNA genes; 2. No. LAGs, the number of LAGLIDADG homing endonuclease genes; 3. No. GIYs, the number of GIY-YIG homing endonuclease genes; 4. No. rnL, rRNA large subunit genes; 5. No. rnS, rRNA small subunit genes; 6. No. HGs, hypothetical protein genes.
Portal ID | Species name | mtDNA size (bp) | No. scf | G+C% | Topology | No. tRNA1 | No. LAGs 2 /GIYs3 | No. rnL 4 | No. rnS 5 | No. HGs 6 |
---|---|---|---|---|---|---|---|---|---|---|
Morcon1 | Morchella conifericola Mel32 | 263666 | 1 | 40.72 | circular | 31 | 31 | 2 | 2 | 23 |
Morsep1 | Morchella septentrionalis NRRL54509 | 264912 | 1 | 40.65 | circular | 31 | 33 | 2 | 1 | 17 |
Morarb1 | Morchella arbutiphila PhC291 | 261722 | 1 | 40.68 | circular | 31 | 31 | 2 | 2 | 33 |
Morbru1 | Morchella brunnea NRRL20869 | 264219 | 1 | 40.88 | circular | 31 | 29 | 2 | 1 | 19 |
Morhis1 | Morchella hispaniolensis Mel18 | 272680 | 1 | 40.54 | circular | 31 | 34 | 2 | 2 | 18 |
MorM21481-1 | Morchella Mel-23 | 254381 | 1 | 40.63 | linear | 28 | 29 | 2 | 2 | 25 |
Mordel1 | Morchella deliciosa PhC191 | 304819 | 1 | 40.67 | circular | 31 | 38 | 5 | 3 | 14 |
Morkaki1 | Morchella kakiicolor PhC280 | 339294 | 1 | 42.2 | linear | 33 | 31 | 1 | 2 | 26 |
Morsem1 | Morchella sp. SEM | 339433 | 1 | 42.2 | circular | 33 | 34 | 1 | 2 | 33 |
Morgal1 | Morchella sp. GAL | 340119 | 1 | 42.33 | circular | 32 | 33 | 1 | 2 | 3 |
Mordis1 | Morchella sp. DIS | 339404 | 1 | 42.2 | circular | 33 | 34 | 1 | 2 | 32 |
Mordun1 | Morchella dunalii PhC240 | 339982 | 1 | 42.41 | circular | 31 | 32 | 3 | 2 | 45 |
Morimp1 | Morchella importuna SCYDJ1-A1 | 274206 | 2 | 38.22 | linear | 30 | 24 / (2) | 2 | 2 | 1 |
Morexi1 | Morchella eximia NRRL26621 | 305324 | 1 | 41.46 | circular | 32 | 40 / (1) | 1 | 3 | 3 |
Morexim1 | Morchella eximia DOB1602 | 282169 | 1 | 41.85 | circular | 32 | 28 / (1) | 1 | 2 | 33 |
Morpop1 | Morchella populiphila NRRL22315 | 370799 | 1 | 40.18 | linear | 32 | 48 | 1 | 3 | 5 |
Morpun1 | Morchella punctipes GB769 | 351597 | 1 | 40.57 | linear | 30 | 43/ (1) | 1 | 2 | 13 |
Mortrid1 | Morchella tridentina NRRL54570 | 303561 | 1 | 40.06 | circular | 31 | 41 | 3 | 2 | 26 |
MorM1934m1-1 | Morchella fluvialis | 558743 | 1 | 46.81 | linear | 34 | 20 | 1 | 2 | 47 |
MorvulMes17-1 | Morchella vulgaris Mes-17 | 561093 | 2 | 46.91 | linear | 32 | 21 | 2 | 2 | 108 |
Morpra1 | Morchella prava Mes7 | 565090 | 1 | 46.79 | circular | 32 | 22 | 2 | 2 | 56 |
Morper1 | Morchella peruviana NRRL66754 | 554401 | 1 | 46.1 | circular | 32 | 29 | 1 | 2 | 68 |
Morulm1 | Morchella ulmaria NRRL36825 | 558995 | 1 | 46.92 | linear | 33 | 20 / (1) | 3 | 2 | 45 |
Morame1 | Morchella americana PhC192 | 555871 | 1 | 48.33 | linear | 32 | 19 | 2 | 2 | 36 |
Mordim1 | Morchella diminutiva Mes2 | 471506 | 1 | 46.16 | circular | 33 | 22 | 2 | 1 | 30 |
Morpal1 | Morchella steppicola | 351320 | 1 | 41.23 | circular | 31 | 34 | 2 | 1 | 18 |
Morana1 | Morchella anatolica PhC233 | 475320 | 1 | 42.26 | circular | 32 | 34 | 3 | 63 | |
Morruf1 | Morchella rufobrunnea NRRL28464 | 446548 | 1 | 40.92 | circular | 32 | 30 | 2 | 3 | 51 |
Disven1 | Disciotis venosa NRRL24433 | 265955 | 1 | 37.45 | circular | 32 | 30 | 3 | 2 | 36 |
Vercon1 | Verpa conica TJ0815 | 217659 | 1 | 38.48 | circular | 37 | 25 | 2 | 2 | 47 |
The draft genomes of the Morchellaceae species were generated at the DOE Joint Genome Institute (JGI) using PacBio technology. A PacBio Multiplexed >10 kb w/ Blue Pippin Size Selection library was constructed and sequenced using SEQUELIIe, which generated >500,000 reads, totalling > 6 Gb. CCS data were filtered with the JGI QC pipeline to remove artefacts. Mitochondrial genomes were assembled separately from CCS reads as follows: CCS reads likely to belong to organelles were separated from nuclear genome reads using coverage and GC filtering. A maximum coverage cutoff of (1.5 * kmer coverage peak) and a maximum GC fraction of 0.40 was used to exclude nuclear content using BBTools (B. Bushnell: BBTools software package, http://sourceforge.net/projects/bbmap) version 38.79 [kmer count exact.sh default; bbnorm.sh pigz passes = 1 bits = 16 target = 9999999 min = 162; bbduk.sh maxgc = 0.4]. Initial mitochondrial assemblies were produced using Flye version 2.9-b1768 [-g 100 —asm-coverage 100—pacbio-hifi] (
We analysed the GC content and AT/GC skew for PCGs and the entire genomes of 30 Morchellaceae species. Mitogenome strand asymmetry was assessed using the following formula: AT skew = [A − T]/[A + T] and GC skew = [G − C]/[G + C] (
A phylogenetic tree of the Morchellaceae species was constructed using concatenated 15 PCG sequences using the OrthoFinder algorithm (Emms and Kely 2019). Aligned orthologous protein sequences were obtained using MAFFT (Katoh et al. 2013) and concatenated using trimAl (
We analysed the genome statistics and utilised the Synteny-Governed Overview pipeline (SynGO;
The LAGLIDADG and GIY-YIG sequences were located within the PCGs using Artemis Software (version 18.2.0, http://sanger-pathogens.github.io/Artemis/Artemis/), as presented in Table
The LAGLIDADG and GIY-YIG genes/introns occurring within the core genes among the 30 mitogenomes.
Core gene | cox1 | nad4 | nad3 | cob | nad1 | nad2 | atp9 | rps3 | rnl | nad5 | nad4L | cox2 | cox3 | rns | Total gene numbers of LAG or GIY ** |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Portal ID | |||||||||||||||
Morcon1 | 12/8 | /1 | 8/4 | /2 | /1 | /1 | 3/7 | 2/2 | /4 | 31/30 | |||||
Morsep1 | 12/8 | /1 | 1/2 | /2 | /1 | 4/7 | 1 | 3/3 | /4 | 33/28 | |||||
Morarb1 | 11/8 | /1 | 8/4 | /2 | /1 | /1 | 3/7 | 1 | 2/2 | /4 | 31/30 | ||||
Morbru1 | 11/8 | /1 | 7/4 | /2 | /1 | 3/7 | 2/2 | /4 | 29/29 | ||||||
Morhis1 | 9/7 | /1 | 6/5 | 1/3 | /1 | 6/8 | 1 | 3/3 | 1/4 | 34/32 | |||||
MorM21481-1 | 11/8 | /1 | 8/4 | /2 | /1 | 3/7 | 1 | 2/2 | /4 | 29/29 | |||||
Mordel1 | 10/7 | /1 | 6/4 | /2 | /1 | /1 | 5/7 | 4/4 | /4 | 38/31 | |||||
Morkaki1 | 11/8 | /1 | 1 | 7/5 | 1/3 | /1 | 1/7 | 1/2 | /4 | 31/31 | |||||
Morsem1 | 12/8 | /1 | 1 | 7/5 | 1/3 | /1 | 1/7 | 1/2 | /4 | 34/31 | |||||
Morgal1 | 12/8 | /1 | 1 | 7/4 | 1/3 | /1 | 1/7 | 1/2 | /4 | 33/30 | |||||
Mordis1 | 12/8 | /1 | 1 | 7/5 | 1/3 | /1 | 1/7 | 1/2 | /4 | 34/31 | |||||
Mordun1 | 12/8 | /1 | 1 | 7/5 | 1/3 | /1 | 1/7 | 2/3 | /4 | 32/32 | |||||
Morimp1 | 10 (1 GIY) /9 | /1 | 5 (*1 rps3) /3 | /2 | /3 | 1 | /5 | 3/3 | /4 | 26 (2 GIYs) /30 | |||||
Morexi1 | 12/9 | 1/1 | 1 | 8/4 | 1/3 | /1 | /6 | 1 | 1/2 | /4 | 1 | 41 (1 GIY) /30 | |||
Morexim1 | 10/9 | 1 | 8/4 | /2 | /1 | /6 | 1 | 1/2 | /4 | 29 (1 GIY) /27 | |||||
Morpop1 | 21/8 | 1/1 | 5/4 | /2 | /1 | 5/6 | 2/2 | /4 | 1 | 48/28 | |||||
Morpun1 | 17/8 | 1/1 | 5/4 | /1 | 4/7 | 2/3 | 1/4 | 44 (1 GIY) /28 | |||||||
Mortrid1 | 10/9 | /1 | 8/4 | 1/3 | /1 | /1 | 3/5 | 1 | 3/2 | /4 | 1 | 41/30 | |||
MorM1934m1-1 | 7/8 | /1 | 2/4 | /2 | /2 | /1 | 4/9 | 1 | 1/3 | /4 | 20/34 | ||||
MorvulMes17-1 | 7/8 | /1 | 2/4 | /2 | /2 | 3/9 | 1/3 | /4 | 21 /33 | ||||||
Morpra1 | 7/7 | /1 | 2/4 | /2 | /2 | /2 | 3/9 | 1/4 | /4 | 22/35 | |||||
Morper1 | 8/8 | /1 | 3/4 | /2 | /2 | /2 | 3/9 | 2/4 | /4 | 29/36 | |||||
Morulm1 | 8/8 | /1 | 3/4 | /2 | /2 | /1 | 2/8 | 1/3 | /4 | 21 (1 GIY) /33 | |||||
Morame1 | 6/7 | /1 | 1/4 | /2 | /2 | /2 | 3/9 | 1/3 | /4 | 19/34 | |||||
Mordim1 | 6/8 | /1 | 3/3 | /2 | /2 | 1 | 3/9 | 1 | 1/3 | 1/4 | 22/32 | ||||
Morpal1 | 9/9 | /1 | 11/4 | /2 | /1 | 1/4 | 1 | 1/3 | /4 | 1 | 34/28 | ||||
Morana1 | 12/9 | /1 | 1/2 | /3 | /2 | /1 | 6/9 | 2/5 | 1/3 | 34/35 | |||||
Morruf1 | 9/11 | /1 | 1/2 | 1/3 | /2 | /2 | 7/9 | 1/4 | 1/3 | 1 | 30/37 | ||||
Disven1 | 7/8 | 7/3 | /1 | 3/5 | 1 | /2 | /3 | 30/22 | |||||||
Vercon1 | 5/4 | 1/2 | /2 | /2 | 1/3 | 2/4 | 25/17 |
Mitogenome Mitochondrial genome
HEG Homing endonuclease gene
HGT Horizontal gene transfer
ORF Open reading frame
ML Maximum Likelihood
PCG Protein-coding gene
atp ATP synthase
cox cytochrome c oxidase
cob cytochrome b-coding gene
NADH Nicotinamide adenine dinucleotide
rps ribosomal protein
Mitochondrial genomes of 30 Morchellaceae species were sequenced and annotated. The selected species included false morels, blushing and black and yellow morels, representing distinct ecological lifestyles including soil/litter decomposers, endophytes and Y-mycorrhizal species (
Overview of 30 mitogenomes. General genomic features includes 30 Morchellaceae species in the evolutionary order according to the maximum likelihood tree (see Methods). The trophic type indicates N/A: no data. B/E: Biotrophic/endophytic. S/B/E: Saprotrophic/Biotrophic/Endophytic. The order of 15 protein-coding genes (PCGs), and the size of genomes with the number of scaffolds. Phenotypic groups are colour-coded. Grey: Black morels. Yellow: Yellow morels. Red: Blushing morels. Green: False morels. Green gradient bars show the size of the scaffolds and total size of the genomes. The bubbles beside the graph indicate the number of scaffolds in the genome assembly. Note that the gene positions were adjusted in a circular way to facilitate visible relative comparisons. See the linear version of detailed syntenic comparisons (Suppl. material
The length of mitogenomic core genes. The core genes are abbreviated. atp: ATP synthase. cob: apocytochrome b; cox: cytochrome c oxidase. nad: NADH dehydrogenase. rnl: Large subunit rRNA. rns: small subunit rRNA. rps: ribosomal protein. The species are in the evolutionary order based on a multi-gene maximum likelihood tree constructed (see Methods). Phenotypic groups are colour-coded. Grey: Black morels. Yellow: Yellow morels. Red: Blushing morels. Green: False morels.
The gene order of tRNA and rRNA in the mitogenomes. The species are in the evolutionary order based on a multi-gene maximum likelihood tree constructed (see Methods). Phenotypic groups are colour-coded. Grey: Black morels. Yellow: Yellow morels. Red: Blushing morels. Green: False morels. See details (Suppl. material
Maximum Likelihood phylogenetic analysis was performed using concatenated amino acid sequences from the 15 PCGs (Fig.
PCGs, tRNA genes and rRNA genes were annotated for the 30 Morchellaceae mitogenomes. Fifteen core PCGs were detected: atp6, atp8, atp9, cob, cox1, cox2, cox3, nad1, nad2, nad3, nad4, nad4L, nad5, nad6 and rps3. Additionally, a single rps3 gene, involved in transcriptional regulation, was identified (Fig.
At the gene level, several PCGs in yellow and blushing morels were larger than their orthologs in black morels, accounting for the mitogenome enlargement observed in these groups (Fig.
The GC content ranged from 37.45% to 48.33%. Morchella americana (Morame1) had the highest GC content. Yellow morels displayed a higher GC content than black morels and false morels had the lowest GC content. Upon closer examination, the average GC content of each PCG in the 30 fungi samples varied from 25.17% for atp8 to 44.42% for cox3. Notably, nad1, nad2, nad4 and cob showed higher GC contents in yellow morels than in black morels (Fig.
A clear pattern of positive AT skew (0.016–0.15) was observed for cox1, cox2, nad2, cob, atp6, atp8, nad3, nad4, nad6 and nad4L, indicating a higher frequency of A than that of T in the forward strand. Conversely, atp6, atp8, nad3, nad6 and rps3 showed a negative AT skew, ranging from −0.065 to −0.25. Additionally, all PCGs, except nad1, atp9, cox3 and nad5, exhibited positive or negative AT skew for each PCG amongst the different models. Furthermore, all PCGs, except for atp8, atp6, nad3, nad6 and rps3, displayed a positive GC skew ranging from 0.022 to 0.122, indicating a higher frequency of G than C in the forward strand. M. importuna rps3 exhibited a positive GC skew with a value of 0.385 (Fig.
We assessed mitogenome gene synteny with a specific focus on the spatial distribution of PCGs across black, yellow and blushing morels (Fig.
Comparisons of atp6 and atp8 amongst the 30 morels revealed distinct patterns (Suppl. material
The positions of tRNA genes exhibited a remarkable degree of consistency across various species (Fig.
All the Morchellaceae species examined in this study contained tRNAs corresponding to all 20 natural amino acids within their mitogenomes. Notably, trnR (tRNA-Arg (ACG) and tRNA-Arg (TCT)) were observed with 4-7 copies, whereas trnM (tRNA-Met(CAT)), trnS (tRNA-Ser(TGA) and tRNA-Ser(GCT)), trnL (tRNA-Leu (TAA) and tRNA-Leu (TAG)) and trnI (tRNA-Ile (GAT) and tRNA-Ile (TAT)) exhibited 2-4 copies. The anticodons associated with trnR, trnS, trnL and trnI were CGU and AGA, UCA and AGC, UUA and CUA and AUC and AUA, respectively (Fig.
The positions of the rRNA genes within the Morchellaceae species in this study displayed a notable level of consistency, with rnS consistently appearing in close proximity to the cox1 gene. However, certain morel species exhibit additional rRNA genes and rRNA rearrangements within their mitogenomes. For instance, M. deliciosa (Mordel1) has five rnL and three rnS genes, whereas M. tridentina (Mortrid1) and M. ulmaria (Morulm1) possess three rnL and two rnS genes. Furthermore, some species featured only one copy of the rnL or rnS gene or lacked it entirely, leading to distinct gene order variations (Fig.
A total of 925 LAGLIDADG (LAGs) and GIY-YIG (GIYs) genes and 913 introns have been identified within the mitogenomes of Morchellaceae. Individual species exhibited a range of 19–48 LAGs or GIYs. The presence and distribution of LAGs and GIYs were predominantly observed in PCGs, such as cox1, cob, cox2 and nad5 (Table
The LAGs within each morel species displayed a significant diversity in size and content (Fig.
Phylogenetic trees of LAGLIDADG coding genes. Maximum-likelihood phylogenetic trees were constructed with three representative morel species based on the amino acid sequences of LAGLIDADG genes in their mitogenomes a Morchella populiphila NRRL22315 (Morpop1), a black morel b Morchella peruviana NRRL66754 (Morper1), a yellow morel c Morchella anatolica PhC233 (Morana1), a blushing morel. Support values are shown at the nodes. Clades represent the amino acid sequences of all LAGLIDADG genes, which are either inserted within core genes or located externally in the mitogenomes. The genes are labelled with detailed information. For example, ”Morpop1-LAG25-cox1-21” describes the 25th LAGLIDADG gene inserted into the core gene cox1 at position 21 in M. populiphila NRRL22315, while, “Morper1-LAG15” denotes the 15th LAGLIDADG gene located outside the core genes in M. peruviana NRRL66754.
Alignments of LAGLIDADG amino acid sequences. Homologous amino acid sequences of LAGLIDADG coding genes were aligned across the Morchella species and false morels. These alignments encompass five representative LAGLIDADG genes present in the core genes; a cox1, b cox2, c cob, d nad5, and e outside the core genes. "Morexi1-LAG19-cox1-3" denotes the 19th LAGLIDADG gene found at the position 3 of the core gene cox1 in Morchella eximia NRRL26621 (Morexi1).
In this study, we sequenced the mitogenomes of species belonging to false, blushing, black and yellow morels of the Morchellaceae family. The assembly sizes for these mitogenomes varied from 217.7 kb to 565.1 kb, as shown in Table
Mitochondrial genes, which are widely used in population genetics, evolution and phylogenetic analyses, present independent evolutionary characteristics that are distinct from those of nuclear genomes. The abundance of molecular markers, particularly mitochondria-specific genes, such as atp6, atp8, atp9, cob, cox1, cox2, cox3, nad1, nad2, nad3, nad4, nad4L, nad5 and nad6, renders them valuable tools (
Although cox1 and other PCGs have not been extensively utilised as molecular markers in fungal phylogenetic analyses owing to limited mitochondrial genome availability, our study revealed identical and well-supported evolutionary tree topologies for Morchellaceae fungi, based on mitochondrial gene sets (Fig.
In Fungi, the length and genomic composition of mitogenomes may be influenced by the presence of accessory elements such as introns, HEGs and uORFs, introduced through horizontal gene transfer (
Previous studies have demonstrated variations in the number and location of HEGs amongst the mitogenomes of six Lactarius species, which significantly contributes to differences in mitogenome organisation and size (
For instance, Disven1-LAG13-cox1-6 was shared by 25 morels and one false-morel within cox1 (Fig.
The findings of this study also underscore the dynamic nature of Morchella mitogenomes and suggest a possible link between HEG abundance and evolutionary adaptability of these fungi (
A particularly intriguing, yet complex question pertains to the trophic status of morels. For the past two decades, it has been hypothesised that certain yellow morel species may form weak associations with trees (Y-mycorrhiza). However, this contention has not yet been substantiated by experimental studies. More broadly, it has been posited that yellow morels (Esculenta group) are associated with root systems during their life cycle, whereas black morels (Elata group) are exclusively saprotrophic. Our observation of a slightly larger genome size in yellow morels raises the question whether this difference is related to their ecology or biology. The observed variation in mitogenome size arose from differences in intron content, mobile genetic elements and repeat sequences (Tables
Owing to their exceptional flavour, functional attributes and limited availability, the market value of wild morels has increased to approximately $300 per kilogram (dried) (
This study analysed the mitochondrial genomes of 30 Morchellaceae species, encompassing yellow, black, blushing and false morels, to elucidate their genetic architecture and ecological significance. The investigation revealed that these mitogenomes, ranging from 217 to 565 kbp in length, exist as either circular or linear DNA molecules with GC content between 38% and 48%. Although a substantial degree of gene order conservation was observed, several rearrangements were identified, most notably in Morchella importuna. This study also examined the diversity and phylogenetic relationships of HEGs within these mitogenomes, detecting between 19 and 48 HEGs per species. These observations support the contributions of introns and HEGs to mitogenomic diversity in morels. This research provides a novel perspective on the evolutionary dynamics of the Morchellaceae family.
We thank Emmanuelle Morin (INRAE) for useful discussions and constructive feedback regarding the construction of the phylogenic tree and Laure Fauchery and Annegret Kohler for providing DNA/RNA material for several species of morels used in this study. We also thank Philippe Clowez and Tim James for providing Morchella and Verpa isolates, respectively and Tom Bruns for permission to use an unpublished genome.
The authors have declared that no competing interests exist.
No ethical statement was reported.
All the fungal strains used in this study have been legally obtained, respecting the Convention on Biological Diversity (Rio Convention).
This work was supported by several grants and funding sources: the JGI Community Science Program proposals (10.46936/10.25585/60001060 awarded to FMM and GB, funded by the U.S. Department of Energy Office of Science, Biological and Environmental Research Division [LANLF59T] and the U.S. National Science Foundation Division of Environmental Biology [DEB-1946445]); 10.46936/10.25585/60001080 to Tom Bruns; and 10.46936/fics.proj.2019.50958/60000125 to PC. The Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy Contract no. DE-AC02-05CH11231. Additional funding was provided by the Laboratory of Excellence ARBRE (ANR-11-LABX-0002-01) to FM and by the China Scholarship Council and the National Natural Science Foundation of China (NSFC 31860520) for GT.
FM and GT designed the research; GT, FM, SA and SM performed the research and analysed the data; XJZ and HP analysed the data; GT and FM wrote the manuscript; KL, AC, RH, GB, IG and PC reviewed and improved the manuscript. All the authors have read and agreed to the published version of the manuscript.
Gang Tao https://orcid.org/0000-0002-0882-3752
Steven Ahrendt https://orcid.org/0000-0001-8492-4830
Shingo Miyauchi https://orcid.org/0000-0002-0620-5547
XiaoJie Zhu https://orcid.org/0009-0004-9333-5893
Hao Peng https://orcid.org/0009-0005-3348-1861
Kurt Labutti https://orcid.org/0000-0002-5838-1972
Alicia Clum https://orcid.org/0000-0002-5004-3362
Richard Hayes https://orcid.org/0000-0002-5236-7918
Patrick S. G. Chain https://orcid.org/0000-0003-3949-3634
Igor V. Grigoriev https://orcid.org/0000-0002-3136-8903
Gregory Bonito https://orcid.org/0000-0002-7262-8978
Francis M. Martin https://orcid.org/0000-0002-4737-3715
All of the data that support the findings of this study are available in the main text or Supplementary Information.
Comparisons of gene order in 30 mitochondrial genomes
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AT/GC content and skew
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Genomic coodinates of Morchellaceae mitogenomes
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Genomic statistics used for PERMANOVA
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Statistically significant variables in PERMANOVA
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Amino acid sequences of LAGs and GIYs
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Supplementary figures
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Explanation note: fig. S1.1–1.5: Circular representation of the 30 Morchella mitogenomes; fig. S2: Linear representation of syntenic mitogenomes in black morels; fig. S3: Linear representation of syntenic mitogenomes in yellow and blushing morels; fig. S4: Phylogenetic trees of atp6 and atp8 genes; fig. S5: Trends of genomic features by fungal groups; fig. S6: Significant variables driving trends in 30 mitochondrial genomes; fig. S7: Correlated mitochondrial genes and genomes in size.