Excavation of Genes Responsive to Brassinosteroids by Transcriptome Sequencing in Adiantum flabellulatum Gametophytes

Abstract

Brassinosteroids (BRs) are a class of polyhydroxysteroid plant hormones; they play important roles in the development and stress resistance of plants. The research on BRs has mainly been carried out in angiosperms, but in ferns—research is still limited to the physiological level and is not in-depth. In this study, Adiantum flabellulatum gametophytes were used as materials and treated with 10−6 M brassinolide (BL). The differentially expressed genes (DEGs) responsive to BRs were identified by transcriptome sequencing, GO, KEGG analysis, as well as a quantitative real-time polymerase chain reaction. From this, a total of 8394 DEGs were screened. We found that the expressions of photosynthetic genes were widely inhibited by high concentrations of BL in A. flabellulatum gametophytes. Moreover, we detected many BR synthase genes, except BR6ox2, which may be why castasterone (CS) rather than BL was detected in ferns. Additionally, we identified (for the first time) that the expressions of BR synthase genes (CYP90B1, CYP90C1, CYP90D1, CPD, and BR6ox1) were negatively regulated by BL in fern gametophytes, which indicated that ferns, including gametophytes, also needed the regulatory mechanism for maintaining BR homeostasis. Based on transcriptome sequencing, this study can provide a large number of gene expression data for BRs regulating the development of fern gametophytes.

Light response of gametophyte in Adiantum flabellulatum: transcriptome analysis and identification of key genes and pathways

“…Spores of A. flabellulatum were collected from the rubber forest at Ma’an Mountain (109.519°E, 19.501°N) in Danzhou, Hainan Province, China, as described by Cai et al. (2022b) .…”

“…The module genes were annotated and classified using Blast2GO (v2.5.0) for Gene Ontology (GO, http://www.geneontology.org/ ) and Blastx (v2.2.23) and Diamond (v0.8.31) tools for KEGG ( http://www.genome.jp/kegg/ ) annotation and classification, respectively ( Cai et al., 2022b ). Enrichment analysis was performed using the Phyper function package in the R software.…”

“…Spores of A. flabellulatum were collected from the rubber forest at Ma'an Mountain (109.519°E, 19.501°N) in Danzhou, Hainan Province, China, as described by Cai et al (2022b). The spores were sterilized with 0.1% HgCl 2 for 5 min, washed with sterile water five times, and then plated on 1/4 MS solid medium (3% w/v sucrose and 0.7% w/v agar).…”