Fungal isolates GZUIFR-

The low lysine content of waxy maize cannot meet the nutritional requirements of humans, livestock, or poultry. In the present study, the high-lysine genes o2 and o16 were backcrossed into wx lines using the maize high-lysine inbreds TAIXI19 (o2o2) and QCL3021 (o16o16) as donors and the waxy maize inbred line QCL5019 (wxwx) as a receptor. In the triple-cross F1, backcross, and inbred generations, the SSR markers phi027 and phi112 within the wx and o2 genes and the SSR marker umc1121 linked to the o16 gene were used for foreground selection. Background selection of the whole-genome SSR markers was performed for the selected individuals. The grain lysine content was determined using the dye-binding lysine method. The waxiness of the grain was determined with the I2-KI staining and dual-wavelength spectrophotometric analysis. The BC2F2 generation included 7 plants of genotype wxwxo2o2O16_, 19 plants of genotype wxwxo16o16O2_, and 3 plants of genotype wxwxo2o2o16o16. In these seeds, the average amylopectin content was 96.67%, 96.87%, and 96.62%, respectively, which is similar to that of QCL5019. The average lysine content was 0.555%, 0.380%, and 0.616%, respectively, representing increases of 75.1%, 19.9%, 94.3%, respectively, over QCL5019. The average genetic background recovery rate of the BC2F3 families was 95.3%, 94.3%, 94.2%, respectively. Among these 3 wxwxo2o2O16O16 families, 4 wxwxo2o2O16o16 families, and 3 wxwxo2o2o16o16 families, the longest imported parent donor fragment was 113.35 cM and the shortest fragment was 11.75 cM. No significant differences in lysine content were found between the BC2F4 seeds and the BC2F3 seeds in these 10 families. This allowed us to increase the lysine content of waxy corn and produce seeds with excellent nutritional characteristics suitable for human consumption, animal feed, and food processing. This may be of significance in the breeding of high-quality corn and in improvement of the nutrition of humans, livestock, and poultry.

The dried sclerotia of Wolfiporia cocos (Schwein.) Ryvarden & Gilb., a traditional Chinese medicine, has triterpenoid as its main active component. Breeding high-yield triterpenoid in W. cocos is an important research topic at present. We screened out two monosporal strains from the same W. cocos 5.78, high-yielding DZAC-Wp-H-29 (H) and low-yielding DZAC-Wp-L-123 (L), and cultured mycelia for 17 days, 34 days, and 51 days, respectively. Transcriptome analysis results showed that triterpenoid synthesis is closely related to gene expression in triterpenoid synthesis pathways (hydroxymethyl glutaryl-CoA reductase (HMGCR), farnesyl diphosphate synthase (FDPS), 4-hydroxybenzoate polyprenyltransferase (COQ2), C-8 sterol isomerase (ERG2), sterol O-acyltransferase (ACAT), tyrosine aminotransferase (TAT), torulene dioxygenase (CAO2), and sterol-4alpha-carboxylate 3-dehydrogenase (erg26)), and is limited by the expression of enzyme M20 combined with domain protein peptide (Pm20d2), aryl-alcohol dehydrogenase (norA), ISWI chromatin-remodeling complex ATPase ISW2, GroES-like protein (adh), cytochrome P450 (ftmP450-1), and unknown proteins unigene0001029 and unigene0011374. In addition, maintaining high triterpenoid accumulation in W. cocos may require a stable membrane structure, so the accumulation ability may be related to the high synthesis ability of sterols. The low accumulation of triterpenoid in W. cocos may be due to the products of key enzymes increasing flow to other pathways.

Two new keratinophilic fungal species, Chrysosporium jingzhouense and C. clavisporum, were isolated from farmland soil of Jingzhou City, Hubei Province, and from plant root soil of Guigang City, Guangxi Province, China, respectively, using child hair as bait. Molecular and morphological characters were used to identify taxonomic status. The phylogeny shows C. jingzhouense is clustered with C. articulatum and C. keratinophilum; while C. clavisporum appears to be related to C. qinghaiense, C. indicum and C. linfenense. These previously described Chrysosporium species can be easily distinguished from our proposed new species based on morphology alone. The holotypes, ex-types and ex-isotypes have been deposited in the Institute of Fungus Resources (GZAC).

The fungus Wolfiporia cocos has wide-ranging and important medicinal value, and its dried sclerotia are used as a traditional Chinese medicine. Modern studies have shown that triterpenoid, the active ingredient of W. cocos, have a variety of pharmacological effects. The aim of our research was to determine the key genes related to triterpenoid biosynthesis, which may be useful for the genetic modification of cell-engineered bacteria for triterpenoid biosynthesis. In this study, two monospore strains, DZAC-WP-H-29 (high-yielding) and DZAC-WP-L-123 (low-yielding), were selected from the sexually propagated offspring of strain 5.78 of W. cocos, and the mycelia were cultured for 17, 34, and 51 days, respectively. Weighted gene co-expression network analysis (WGCNA) method was used to analyze transcriptional expressions. The results show that eight core genes (ACAT1-b, hgsA, mvd1, SQLE, erg6, TAT, erg26, and erg11) are associated with the triterpenoid synthesis pathway, and Pm20d2 and norA outside the pathway may be important genes that influence the biosynthesis and accumulation of W. cocos triterpenoid. The biosynthesis of W. cocos triterpenoid is closely related to the expression of sterol metabolic pathway genes. The role of these genes in triterpenoid synthesis complements our knowledge on the biosynthesis and accumulation of W. cocos triterpenoid, and also provides a reference for the target gene modification of engineered bacteria for the fermentation production of triterpenoid.