RESUMO
Morchella is a genus of fungi with the ability to concentrate Cd both in the fruit-body and mycelium. However, the molecular mechanisms conferring resistance to Cd stress in Morchella are unknown. Here, RNA-based transcriptomic sequencing was used to identify the genes and pathways involved in Cd tolerance in Morchella spongiola. 7444 differentially expressed genes (DEGs) were identified by cultivating M. spongiola in media containing 0.15, 0.90, or 1.50 mg/L Cd2+ . The DEGs were divided into six sub-clusters based on their global expression profiles. GO enrichment analysis indicated that numerous DEGs were associated with catalytic activity, cell cycle control, and the ribosome. KEGG enrichment analysis showed that the main pathways under Cd stress were MAPK signaling, oxidative phosphorylation, pyruvate metabolism, and propanoate metabolism. In addition, several DEGs encoding ion transporters, enzymaticon-enzymatic antioxidants, and transcription factors were identified. Based on these results, a preliminary gene regulatory network was firstly proposed to illustrate the molecular mechanisms of Cd detoxification in M. spongiola. These results provide valuable insights into the Cd tolerance mechanism of M. spongiola and constitute a robust foundation for further studies on detoxification mechanisms in macrofungi that could potentially lead to the development of new and improved fungal bioremediation strategies.
RESUMO
Morchella is a genus of fungi with the ability to concentrate Cd both in the fruit-body and mycelium. However, the molecular mechanisms conferring resistance to Cd stress in Morchella are unknown. Here, RNA-based transcriptomic sequencing was used to identify the genes and pathways involved in Cd tolerance in Morchella spongiola. 7444 differentially expressed genes (DEGs) were identified by cultivating M. spongiola in media containing 0.15, 0.90, or 1.50 mg/L Cd2+ . The DEGs were divided into six sub-clusters based on their global expression profiles. GO enrichment analysis indicated that numerous DEGs were associated with catalytic activity, cell cycle control, and the ribosome. KEGG enrichment analysis showed that the main pathways under Cd stress were MAPK signaling, oxidative phosphorylation, pyruvate metabolism, and propanoate metabolism. In addition, several DEGs encoding ion transporters, enzymaticon-enzymatic antioxidants, and transcription factors were identified. Based on these results, a preliminary gene regulatory network was firstly proposed to illustrate the molecular mechanisms of Cd detoxification in M. spongiola. These results provide valuable insights into the Cd tolerance mechanism of M. spongiola and constitute a robust foundation for further studies on detoxification mechanisms in macrofungi that could potentially lead to the development of new and improved fungal bioremediation strategies.
RESUMO
A strain of Q7-31 was isolated from Qinghai-Tibet Plateau and was identified as Fusarium sp. based on its morphological characteristics and ITS rDNA gene sequence analysis. It has the highest capacity of degrading cell wall activity compared with other 11 strains. To do research on its xylanase activity of Fusarium sp. Q7-31 while the degrading the rice cell walls, the complete gene xyn8 that encodes endo-1, 4-¥â-xylanase secreted by Fusarium sp. Q7-31 was cloned and sequenced. The coding region of the gene is separated by two introns of 56bp and 55bp. It encodes 230 amino acid residues of a protein with a calculated molecular weight of 25.7 kDa. The animo acids sequence of xyn8 gene has higher similarity with those of family 11 of glycosyl hydrolases reported from other microorganisms. The nature peptide encodeing cDNA was subcloned into pGEX5x-1 expression vector. The recombinant plasmid was expressed in Escherichia coli BL21-CodonPlus (DE3)-RIL, and xylanase activity was measured. The expression fusion protein was identified by SDS-PAGE and Western blotting, a new specific band of about 52kDa was identified when induced by IPTG. Enzyme activity assay verified the recombinants proteins as a xylanase. A maxium activity of 2.34U/ mg, the xylanase had optimal activity at pH 6.0 and temperature 40¨¬C .