Within the framework of the ‘Comparative genomics of early
diverging terrestrial fungi and their bacterial
endosymbionts’ CSP1450 project, we are exploring interactions
and evolutionary histories of early diverging lineages of
terrestrial fungi and their endobacteria (Desirò et al.
2018; Uehling et al. 2017). Towards this goal, we are sequencing
metagenomes and metatranscriptomes of a diverse panel of fungi in
Mucoromycota that host endohyphal bacteria.
Mortierella is a large genus of fungi within
Mucoromycota, formerly classified as zygomycetes. These fungi are
industrially important given their unique fatty acid and lipid
metabolism, which is of interest for biofuel production.
Mortierella species are distributed globally and are
frequently isolated and detected in soils and plant rhizospheres.
Many species grow rapidly, in part owing to their coenocytic
mycelium that has occasional septa and frequent anastomoses.
Mortierella are generally considered to be haploid and
heterothallic, although some species are known to be homothallic
(Gams et al. 1972). Of particular interest, Mortierella
species can harbor endobacteria within their cells, which affect
the fungal host's growth and physiology (Uehling et al.
2017).
Mortierella elongata NVP64 was isolated in 2015 from a
wildlife forage field soil sample collected in Jackson, Michigan,
USA. It displays a rosette pattern of growth (Fig 1). Young
mycelium is coenocytic. When tissue is broken or dying, septa form
and cell contents are progressively retracted into chlamydospores
(Fig 2). The most common form of reproduction of NVP64 is through
asexual sporangiospores and chlamydospores. Successful sexual
mating of this isolate results in zygospores (Fig 3), which are
characterized by a circular inner layer surrounded by a waved loose
outer layer and remaining empty suspensor (Kuhlman, 1972).
Mortierella elongata NVP64 contains the endosymbiotic
bacteria Mycoavidus cysteinexigens (Ohshima et al.
2016).
References:
Desirò, Alessandro, Zhen Hao, Julian A. Liber, Gian Maria Niccolò Benucci, David Lowry, Robert Roberson, and Gregory Bonito. 2018. “Mycoplasma-Related Endobacteria within Mortierellomycotina Fungi: Diversity, Distribution and Functional Insights into Their Lifestyle.” The ISME Journal 12 (7): 1743–57.
Gams, W., Chiu-Yuan Chien, and K. H. Domsch. 1972. “Zygospore Formation by the Heterothallic Mortierella elongata and a Related Homothallic Species, M. epigama Sp.nov.” Transactions of the British Mycological Society 58 (1): 5–IN2.
Kuhlman, E. G. 1972. “Variation in Zygospore Formation among Species of Mortierella.” Mycologia 64 (2): 325 – &.
Ohshima, Shoko, Yoshinori Sato, Reiko Fujimura, Yusuke Takashima, Moriyuki Hamada, Tomoyasu Nishizawa, Kazuhiko Narisawa, and Hiroyuki Ohta. 2016. “Mycoavidus cysteinexigens Gen. Nov., Sp. Nov., an Endohyphal Bacterium Isolated from a Soil Isolate of the Fungus Mortierella elongata.” International Journal of Systematic and Evolutionary Microbiology, February. https://doi.org/10.1099/ijsem.0.000990.
Uehling, J., A. Gryganskyi, K. Hameed, T. Tschaplinski, P. K. Misztal, S. Wu, Desirò A, et al. 2017. “Comparative Genomics of Mortierella elongata and Its Bacterial Endosymbiont Mycoavidus cysteinexigens.” Environmental Microbiology.
Genome Reference(s)
Mathieu D, Bryson AE, Hamberger B, Singan V, Keymanesh K, Wang M, Barry K, Mondo S, Pangilinan J, Koriabine M, Grigoriev IV, Bonito G, Hamberger B
Multilevel analysis between Physcomitrium patens and Mortierellaceae endophytes explores potential long-standing interaction among land plants and fungi.
Plant J. 2024 Jan 24;():. doi: 10.1111/tpj.16605