Profiling and Quantifying Differential Gene Transcription Provide Insights into Ganoderic Acid Biosynthesis in Ganoderma lucidum in Response to Methyl Jasmonate

Abstract

Ganoderma lucidum is a mushroom with traditional medicinal properties that has been widely used in China and other countries in Eastern Asia. Ganoderic acids (GA) produced by G. lucidum exhibit important pharmacological activities. Previous studies have demonstrated that methyl jasmonate (MeJA) is a potent inducer of GA biosynthesis and the expression of genes involved in the GA biosynthesis pathway in G. lucidum. To further explore the mechanism of GA biosynthesis, cDNA-Amplified Fragment Length Polymorphism (cDNA-AFLP) was used to identify genes that are differentially expressed in response to MeJA. Using 64 primer combinations, over 3910 transcriptionally derived fragments (TDFs) were obtained. Reliable sequence data were obtained for 390 of 458 selected TDFs. Ninety of these TDFs were annotated with known functions through BLASTX searching the GenBank database, and 12 annotated TDFs were assigned into secondary metabolic pathways by searching the KEGGPATHWAY database. Twenty-five TDFs were selected for qRT-PCR analysis to confirm the expression patterns observed with cDNA-AFLP. The qRT-PCR results were consistent with the altered patterns of gene expression revealed by the cDNA-AFLP technique. Additionally, the transcript levels of 10 genes were measured at the mycelium, primordia, and fruiting body developmental stages of G. lucidum. The greatest expression levels were reached during primordia for all of the genes except cytochrome b2 reached its highest expression level in the mycelium stage. This study not only identifies new candidate genes involved in the regulation of GA biosynthesis but also provides further insight into MeJA-induced gene expression and secondary metabolic response in G. lucidum.

UDP-glucose pyrophosphorylase influences polysaccharide synthesis, cell wall components, and hyphal branching in Ganoderma lucidum via regulation of the balance between glucose-1-phosphate and UDP-glucose

“…However, there has been little basic research on this mushroom due to its poor genetic transformation system. Fortunately, in recent years, many studies have investigated the molecular genetics of G. lucidum, and a number of techniques have been developed, including genome analysis and EST analysis, and genes involved in growth and secondary metabolic biosynthesis have been characterized (Chen et al, 2012;Ren et al, 2013;Shi et al, 2012b). Furthermore, the establishment of genetic transformation systems, including transcriptional gene silencing (Mu et al, 2012) and gene overexpression (Shi et al, 2012a) systems, has enabled the further research of G. lucidum.…”

“…Total RNA was extracted as described previously (Ren et al, 2013). RNA samples isolated from vegetative hyphae harvested from 7-day-old MCM cultures were used for analysis.…”

Proteome Exploration to Provide a Resource for the Investigation of Ganoderma lucidum

“…lucidum of different strains and at different developmental stages have recently been sequenced [19–24]. By analyzing the G .…”

In silicoanalysis of MeJA-induced comparative transcriptomes inBrassica oleraceaeL.var. capitata

“…4A). Several known genes including lipoxygenase, myrosinaseassociated protein, and lipase, were read abundantly as reported in other plants (Ren et al 2013). Other uncharacterized genes might be cabbage-specific suitable candidates.…”