Abstract
BackgroundGarden 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.ResultsDe 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.ConclusionsOur 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.
Highlights
Garden asparagus (Asparagus officinalis) is a highly valuable vegetable crop of commercial and nutritional interest
Sequencing and de novo transcriptome assembly of asparagus flower buds We performed Illumina sequencing on the male and female flower bud samples, and each sample was prepared in two replicates
Our results further showed two stamen-specific genes, namely, Arabidopsis LAT59 ORTHOLOG (AT59) and SUGAR TRANSPORTAER 11 (STP11), which played a role in pollen tube formation and growth [27]
Summary
Garden asparagus (Asparagus officinalis) is a highly valuable vegetable crop of commercial and nutritional interest. The development and maintenance of sex-specific phenotypes, especially male and female flowers in different individuals, are under a series of metabolic pathways and regulatory genetic networks, in which various genes, transcription factors (TFs), and other regulators, such as microRNAs (miRNAs), are involved [9,10,11]. Similar to those in mammals [12], downstream metabolic pathways and genetic networks essential for sex differentiation in plants may be controlled by upstream sex-determining genes [5]. The mechanisms of sex determination and differentiation in plants are poorly understood
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
