Development, structure and evolutionary significance of seed appendages in Salix matsudana (Salicaceae)

Poplar coma morphogenesis and miRNA regulatory networks by combining ovary tissue sectioning and deep sequencing

Poplar coma, commonly referred to as "seed hairs", is a tuft of trichomes attached to the seed coat that helps seed dispersal. However, they can also trigger health impacts for humans, including sneezing, shortness of breath, and skin irritation. Despite efforts to study the regulatory mechanism of herbaceous trichome formation, poplar coma remains poorly understood. In this study, we showed that the epidermal cells of the funiculus and placenta are the origin of poplar coma based on observations of paraffin sections. Small RNA (sRNA) and degradome libraries were also constructed at three stages of poplar coma development, including initiation and elongation stages. Based on 7,904 miRNA-target pairs identified by small RNA and degradome sequencing, we constructed a miRNA-transcript factor and a stage-specific miRNA regulatory network. By combining paraffin section observation and deep sequencing, our research will provide greater insight into the molecular mechanisms of poplar coma development.

A Selection of Reliable Reference Genes for Gene Expression Analysis in the Female and Male Flowers of Salix suchowensis

Salix is a dioecious plant. Research on the molecular regulation mechanism of male and female inflorescence differentiation and development is necessary to analyze sex differentiation in the willow and the underlying mechanisms of unisexual flower development. However, at present, there are no reference genes suitable for stable expression in the process of willow inflorescence development. In this study, Salix suchowensis was used as the research material, nine candidate reference genes (α-TUB1, α-TUB2, ACT, H2A, DnaJ, CDC2, GAPDH, TIP41, β-TUB) were selected, and qRT-PCR technology was used to detect the expression of each candidate reference gene in female and male flowers at different developmental stages and using five algorithms (geNorm, Normfinder, Delta Ct, BestKeeper, and RefFinder) to comprehensively evaluate the stability of candidate reference genes. The results showed that ACT and DnaJ were stably expressed in all samples and could be used as reference genes. In addition, the reliability of the screening results was further verified via an expression pattern analysis of the CFS gene that encodes flower specific transcription factor in different samples. The stable reference genes selected in this study provide the basis for future research on the expression analysis of functional genes related to the development of male and female flowers of S. suchowensis.