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Ni, Peixiang

Publications and source records attributed to Ni, Peixiang.

The Genome of Ganderma lucidum Provide Insights into Triterpense Biosynthesis and Wood Degradation

Ganoderma lucidum (Reishi or Ling Zhi) is one of the most famous Traditional Chinese Medicines and has been widely used in the treatment of various human diseases in Asia countries. It is also a fungus with strong wood degradation ability with potential in bioenergy production. However, genes, pathways and mechanisms of these functions are still unknown. The genome of G. lucidum was sequenced and assembled into a 39.9 megabases (Mb) draft genome, which encoded 12,080 protein-coding genes and ~83% of them were similar to public sequences. We performed comprehensive annotation for G. lucidum genes and made comparisons with genes in other fungi genomes. Genes in the biosynthesis of the main G. lucidum active ingredients, ganoderic acids (GAs), were characterized. Among the GAs synthases, we identified a fusion gene, the N and C terminal of which are homologous to two different enzymes. Moreover, the fusion gene was only found in basidiomycetes. As a white rot fungus with wood degradation ability, abundant carbohydrate-active enzymes and ligninolytic enzymes were identified in the G. lucidum genome and were compared with other fungi. : The genome sequence and well annotation of G. lucidum will provide new insights in function analyses including its medicinal mechanism. The characterization of genes in the triterpene biosynthesis and wood degradation will facilitate bio-engineering research in the production of its active ingredients and bioenergy.

59 BASIC BIOLOGICAL SCIENCES↗

Evolutionary transients in the rice transcriptome.

The number of protein-coding genes predicted from the rice genome remains much larger than the number of genes for Arabidopsis. Most of the excess rice genes show low similarity to Arabidopsis, and eudicots in general. It is difficult to repudiate these genes because even for the 19,079 non-redundant rice cDNAs that have been sequenced, 34.3% are low similarity. Here, we describe a major contributor to this excess of low similarity genes: the frequent and continued occurrence of gene duplications in plants, and the post- duplicative degradation (i.e. relaxed selection) that is typically expected to occur in one of the two gene copies. The salient feature of this degradation is an increase in Ka/Ks for Ks per available site, respectively. We show that low similarity genes are expressed at lower mRNA and protein levels than other genes, and that regions of the encoded proteins are structurally disordered. Indeed, many are evolutionary “transients” that may be destined to die, even if they remain transcriptionally active for millions of years.

59 BASIC BIOLOGICAL SCIENCES↗