Transcriptome Analysis Reveals Candidate Genes Involved in Light-Induced Primordium Differentiation in Pleurotus eryngii.

Dou Ye,Xue Bai,Fang Du,Qingxiu Hu,Yajie Zou

doi:10.3390/ijms23010435

Abstract

Pleurotus eryngii, a highly valued edible fungus, is one of the major commercially cultivated mushrooms in China. The development of P. eryngii, especially during the stage of primordium differentiation, is easily affected by light. However, the molecular mechanism underlying the response of primordium differentiation to light remains unknown. In the present study, primordium expression profiles under blue-light stimulation, red-light stimulation, and exposure to darkness were compared using high-throughput sequencing. A total of 16,321 differentially expressed genes (DEGs) were identified from three comparisons. GO enrichment analysis showed that a large number of DEGs were related to light stimulation and amino acid biosynthesis. KEGG analyses demonstrated that the MAPK signaling pathway, oxidative phosphorylation pathway, and RNA transport were most active during primordium differentiation. Furthermore, it was predicted that the blue-light photoreceptor WC-1 and Deoxyribodipyrimidine photolyase PHR play important roles in the primordium differentiation of P. eryngii. Taken together, the results of this study provide a speculative mechanism that light induces primordium differentiation and a foundation for further research on fruiting body development in P. eryngii.

Highlights

P. eryngii, known as the king oyster mushroom, is one of the major commercially cultivated mushrooms in China [1]
We focused on the top 20 pathways (Figure 6) and found that the differentially expressed genes (DEGs) in these two comparisons were highly concentrated in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways MAPK signaling pathway (MSPY; ko04011), oxidative phosphorylation (OP; ko00190), and RNA transport (RT; ko03013), implying that signal transduction, material and energy metabolism remained significantly active during primordium differentiation in P. eryngii; this finding deserves special attention
P. eryngii is a typical wood rot fungus that mainly relies on mycelia to secrete extracellular enzymes to degrade lignocellulose in the substrate to maintain growth, to some degree, the degradation are related to the morphogenesis of the fruiting-body [21,22]

Summary

Introduction

P. eryngii, known as the king oyster mushroom, is one of the major commercially cultivated mushrooms in China [1]. Previous studies have demonstrated that primordium formation and differentiation in P. eryngii can be markedly affected by environmental factors, especially light. Blue light stimulates the differentiation of the primordium, while red light exerts an inhibitory effect [4,5]. The mechanism underlying the response of P. eryngii to light during primordium differentiation has not been elucidated. Wang et al found that in C. militaris, photoreceptor knockout mutants failed to form primordia under light exposure, showing that the photo-response mechanism of C. militaris primordium formation directly involves photoreceptors [6]. A comparative transcriptomics analysis of Pleurotus ostreatus revealed that blue light induces primordium differentiation by enhancing the activation of glycolysis and the pentose phosphate pathway, whereas red light weakens glycolysis and pentose phosphate pathway activation to impede this stage of development [7]. The depth and thickness of this brown film directly affect the development of the primordium [9]

Methods

Results

Conclusion