Isolation of differentially expressed sex genes in garden asparagus using suppression subtractive hybridization

Influence of Soil Organic Carbon on the Aroma of Tobacco Leaves and the Structure of Microbial Communities

The soil organic carbon is associated with the plant quality and the microbial community structure. In the present study, carbon fertilizers were applied to paddy soil to elucidate the relationship between soil carbon and neutral aroma substances in both tobacco and soil microbiome by transcriptome sequencing and 16S rDNA-based analysis, respectively. Our results showed that (1) the increase in soil carbon content was closely correlated with the abundance of microorganisms belonging to two classes (which could potentially affect tobacco plants), namely Gammaproteobacteria and Chloroflexia, (2) soil carbon apparently affected tobacco neutral aroma substances, and (3) soil carbon improved neutral aroma substances by affecting the transcriptional processes of sesquiterpenoid and chlorophyll biosyntheses. These results suggest that increased soil carbon-especially active organic carbon-resulted in desirable improvements in aroma substances in tobacco leaves.

Transcriptome sequencing reveals the effect of biochar improvement on the development of tobacco plants before and after topping

The application of biochar is one of the most useful methods for improving soil quality, which is of the utmost significance for the continuous production of crops. As there are no conclusive studies on the specific effects of biochar application on tobacco quality, this study aimed to improve the yield and quality of tobacco as a model crop for economic and genetic research in southern China, by such application. We used transcriptome sequencing to reveal the effects of applied biochar on tobacco development before and after topping. Our results showed that topping affected carbon and nitrogen metabolism, photosynthesis and secondary metabolism in the tobacco plants, while straw biochar-application to the soil resulted in amino acid and lipid synthesis; additionally, it affected secondary metabolism of the tobacco plants through carbon restoration and hormonal action, before and after topping. In addition to the new insights into the impact of biochar on crops, our findings provide a basis for biochar application measures in tobacco and other crops.

Comparative transcriptome analysis reveals differentially expressed genes associated with sex expression in garden asparagus (Asparagus officinalis)

BACKGROUND

Garden asparagus (Asparagus officinalis) is a highly valuable vegetable crop of commercial and nutritional interest. It is also commonly used to investigate the mechanisms of sex determination and differentiation in plants. However, the sex expression mechanisms in asparagus remain poorly understood.

RESULTS

De novo transcriptome sequencing via Illumina paired-end sequencing revealed more than 26 billion bases of high-quality sequence data from male and female asparagus flower buds. A total of 72,626 unigenes with an average length of 979 bp were assembled. In comparative transcriptome analysis, 4876 differentially expressed genes (DEGs) were identified in the possible sex-determining stage of female and male/supermale flower buds. Of these DEGs, 433, including 285 male/supermale-biased and 149 female-biased genes, were annotated as flower related. Of the male/supermale-biased flower-related genes, 102 were probably involved in anther development. In addition, 43 DEGs implicated in hormone response and biosynthesis putatively associated with sex expression and reproduction were discovered. Moreover, 128 transcription factor (TF)-related genes belonging to various families were found to be differentially expressed, and this finding implied the essential roles of TF in sex determination or differentiation in asparagus. Correlation analysis indicated that miRNA-DEG pairs were also implicated in asparagus sexual development.

CONCLUSIONS

Our study identified a large number of DEGs involved in the sex expression and reproduction of asparagus, including known genes participating in plant reproduction, plant hormone signaling, TF encoding, and genes with unclear functions. We also found that miRNAs might be involved in the sex differentiation process. Our study could provide a valuable basis for further investigations on the regulatory networks of sex determination and differentiation in asparagus and facilitate further genetic and genomic studies on this dioecious species.