Project description:The complete mitochondrial genome of Phlebopus portentosus was determined using Illumina sequencing. The circular genome is 42,963 bp in length with GC content of 21.37%. It contains 14 putative protein-coding genes, the ribosomal RNA subunits and 23 tRNAs, all located on the same strand. The evolutionary relationships between P. portentosus and other 23 representative basidiomycete species were revealed based on sequences at the 14 concatenated mitochondrial protein-coding genes.
Project description:BackgroundPhlebopus portentosus and mealy bugs form a fungus-insect gall on the roots of host plants. The fungus and mealy bugs benefit mutually through the gall, which is the key link in the nutritional mechanism of P. portentosus. The cavity of the fungus-insect gall provides an ideal shelter for mealy bugs survival and reproduction, but how does P. portentosus benefit from this symbiotic relationship?Methodology and resultsAnatomical examination of fungus-insect galls revealed that one or more mealy bugs of different generations were living inside the galls. The mealy bug's mouthpart could penetrate through the mycelium layer of the inside of the gall and suck plant juice from the host plant root. Mealy bugs excreted honeydew inside or outside the galls. The results of both honeydew agar medium and quartz tests showed that the honeydew can attract and promote the mycelial growth of P. portentosus. A test of the relationship between the honeydew and the formation of the fungus-insect gall showed that honeydew promoted gall formation.ConclusionsAll experimental results in this study show that the honeydew secreted by mealy bugs can attract and promote the mycelial growth of P. portentosus, forming a fungus-insect gall, because mealy bugs' honeydew is rich in amino acids and sugars.