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Kubicek et al. 2019. Evolution and comparative genomics of the most common Trichoderma species. BMC Genomics 20.

Kubicek et al 2019 Trichoderma genomics

Kubicek, C.P., Steindorff, A.S., Chenthamara, K., Manganiello, G., Henrissat, B., Zhang, J., Cai, F., Kopchinskiy, A.G., Kubicek, E.M., Kuo, A., Baroncelli, R., Sarrocco, S., Noronha, E.F., Vannacci, G., Shen, Q.*, Grigoriev, I.V., Druzhinina, I.S.*, 2019. Evolution and comparative genomics of the most common Trichoderma specieshttps://pubmed.ncbi.nlm.nih.gov/31189469/. BMC Genomics 20.

Background

The growing importance of the ubiquitous fungal genus Trichoderma (Hypocreales, Ascomycota) requires understanding of its biology and evolution. Many Trichoderma species are used as biofertilizers and biofungicides and T. reesei is the model organism for industrial production of cellulolytic enzymes. In addition, some highly opportunistic species devastate mushroom farms and can become pathogens of humans. A comparative analysis of the first three whole genomes revealed mycoparasitism as the innate feature of Trichoderma. However, the evolution of these traits is not yet understood.

Results

We selected 12 most commonly occurring Trichoderma species and studied the evolution of their genome sequences. Trichoderma evolved in the time of the Cretaceous-Palaeogene extinction event 66 (±15) mya, but the formation of extant sections (Longibrachiatum, Trichoderma) or clades (Harzianum/Virens) happened in Oligocene. The evolution of the Harzianum clade and section Trichoderma was accompanied by significant gene gain, but the ancestor of section Longibrachiatum experienced rapid gene loss. The highest number of genes gained encoded ankyrins, HET domain proteins and transcription factors. We also identified the Trichoderma core genome, completely curated its annotation, investigated several gene families in detail and compared the results to those of other fungi. Eighty percent of those genes for which a function could be predicted were also found in other fungi, but only 67% of those without a predictable function.

Conclusions

Our study presents a time scaled pattern of genome evolution in 12 Trichoderma species from three phylogenetically distant clades/sections and a comprehensive analysis of their genes. The data offer insights in the evolution of a mycoparasite towards a generalist.

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Jiang et al. 2019 High-throughput absolute quantification sequencing reveals the effect of different fertilizer applications on bacterial community in a tomato cultivated coastal saline soil. Science of The Total Environment

Jiang S-Q, Yu Y-N, Gao R-W, Wang H, Zhang J, Li R, Long X-H, Shen Q-R, Chen W, Cai F: High-throughput absolute quantification sequencing reveals the effect of different fertilizer applications on bacterial community in a tomato cultivated coastal saline soil. Science of The Total Environment 2019, 687:601-609.

Coastal saline soil is an important reserve land resource that has high potential for agricultural utilization. The present study adopted a high-throughput absolute quantification 16S rRNA sequencing method to investigate the effect of four different fertilization regimes (namely 100% of bio-organic fertilizer, 70% of bio-organic fertilizer +30% of chemical fertilizer, 30% of bio-organic fertilizer +70% of chemical fertilizer, and 100% of chemical fertilizer) on bacterial community assembly in a tomato cultivated saline soil. The results from the field experiment showed that a combination of 70% bio-organic fertilizer plus 30% of chemical fertilizer was the optimal dose to develop tomato cultivation (for improving yield and fruit quality) in this coastal tidal zone. The pot experiment gave the similar results on tomato growth and indicated the application of 70% bio-organic fertilizer plus 30% of chemical fertilizer as the best treatment to active the soil microbiome. The input of nutrients by fertilizers increased the total abundance of bacteria (to >3 fold compared to the initial soil) and simultaneously led to a significant loss of bacterial diversity in soil. The predominant phyla including Proteobacteria, Bacteroidetes and Firmicutes were the main contributors in the microbiome shift especially shown by their remarkable enrichment in the soil that treated by 70% of bio-organic fertilizer and those by the 100% chemical fertilizer. The RDA and Pearson correlation analyses indicated that the soil nutrient availability, especially available P and K, and soil salinity were the key environmental factors that shaped the bacterial community in this ecosystem, though the organic matter content and soil pH also played important roles in microbiome assembly.

Keywords: Absolute quantification 16S-seq; Bio-organic fertilizer; Coastal mud flat; Microbiome; Tomato cultivation.