Integrating expression data and genomic sequences to investigate transcriptional regulation in barley in response to abiotic stress.

Abiotic stress responses are regulated critically at the transcriptional level. Clarifying the intricate mechanisms that regulate gene expression in response to abiotic stress is crucial and challenging. For this purpose, the factors that regulate gene expression and their binding sites in DNA should be determined. By using bioinformatics tools, the differentially expressed probe sets were studied. A meta-analysis of transcriptomic responses to several abiotic stresses in barley was performed. Motif enrichments revealed that AP2/ERF (APETALA2/Ethylene-Responsive Factor) has the most frequent binding sites. We found that the bHLH transcription factor family has the highest number of transcription factor members. Moreover, network construction revealed that AP2 has the highest number of connections with other genes, which indicates its critical role in abiotic stress responses. The present research further predicted 49 miRNAs belonging to 23 miRNA families. This study identified the probable conserved and enriched motifs, which might have a role in the regulation of differentially expressed genes under abiotic stresses. In addition to shedding light on gene expression regulation, a toolbox of available promoters for genetic engineering of crop plants under such abiotic stresses was developed.

Evolved Fusarium oxysporum laccase expressed in Saccharomyces cerevisiae.

Fusarium oxysporum laccase was functionally expressed in Saccharomyces cerevisiae and engineered towards higher expression levels and higher reactivity towards 2,6-dimethoxyphenol, that could be used as a mediator for lignin modification. A combination of classical culture optimization and protein engineering led to around 30 times higher activity in the culture supernatant. The winner mutant exhibited three times lower Km, four times higher kcat and ten times higher catalytic efficiency than the parental enzyme. The strategy for laccase engineering was composed of a combination of random methods with a rational approach based on QM/MM MD studies of the enzyme complex with 2,6-dimethoxyphenol. Laccase mediator system with 2,6-dimethoxyphenol caused fulvic acids release from biosolubilized coal.