Comparative transcriptome analysis of two reproductive modes in Adiantum reniforme var. sinense targeted to explore possible mechanism of apogamy

Abstract

Background Apogamy is a unique asexual reproduction in the ferns, in which somatic cells of gametophytes go through dedifferentiation and then differentiate into haploid sporophytes bypassing fertilization. Restricted to the lack of genomic information, molecular mechanisms of apogamy have remained unclear. Comparative transcriptome analysis was conducted at six stages between sexual reproduction and apogamy in the fern Adiantum reniforme var. sinense , in an effort to identify genes and pathways that might initiate the asexual reproduction. Results Approximately 928 million high-quality clean reads were assembled into 264,791 unigenes with an average length of 615 bp. A total of 147,865 (55.84%) unigenes were successfully annotated. Differential genes expression analysis indicated that transcriptional regulation was more active in the early stage of apogamy compared to sexual reproduction. Further comparative analysis of the enriched pathways between the early stages of the two reproductive modes demonstrated that starch and sucrose metabolism pathway responsible for cell wall was only significantly enriched in asexual embryonic cell initiation. Furthermore, regulation of plant hormone related genes was more vigorous in apogamy initiation. Conclusion These findings would be useful for revealing the initiation of apogamy and further understanding of the mechanisms related to asexual reproduction. Electronic supplementary material The online version of this article (10.1186/s12863-019-0762-8) contains supplementary material, which is available to authorized users.

Full-length transcriptome analysis of Adiantum flabellulatum gametophyte

“…Based on the Illumina HiSeq sequencing platform, the transcriptomes of roots and shoots of Athyrium yokoscense ( Ukai et al, 2020 ), young leaves of Asplenium nidus , young leaves of Asplenium komarovii ( Zhang et al, 2019 ) and sexual reproduction and apogamy of Adiantum reniforme gametophytes ( Fu & Chen, 2019 ) were studied, and 35,681, 89,741, 77,912, 333,352, 264,791 transcripts were obtained, respectively. The sequencing read length of the Illumina HiSeq is short, the mRNAs need to be broken into short fragments before sequencing, and the complete transcripts can be obtained only by splicing.…”

Reticulate evolution in the Pteris fauriei group (Pteridaceae)

“…The exact mechanisms of sexual taxa giving rise to apogamous taxa could be related to environmental factors such as light, water, and sugar 93 – 95 . Some critical genes expressed during reproduction could control the process of apogamy 96 – 100 . Apogamous gametophytes could contribute functional male gametes, which could account for the origin of some triploid taxa in the P. fauriei group.…”

Proteome and Interactome Linked to Metabolism, Genetic Information Processing, and Abiotic Stress in Gametophytes of Two Woodferns

“…Concerning reproduction, sexual versus apomictic expression profiles were analyzed in Ceratopteris thalictroides [22], as well as in the species Adiantum reniforme var. sinense [23]. In addition, some molecular studies were performed on the fern Ceratopteris richardii [5,24]; in one of them, sex determination was found to be accompanied by changes in the transcriptome driving epigenetic reprogramming of the young gametophyte [25]; in another, the WUSCHEL-related homeobox (WOX) gene, which promotes cell division in gametophytes and organ development in sporophytes, was characterized for the first time in ferns [26]; and finally, transcriptional analysis of the young sporophyte showed the conservation of stem cell factors in the root apical meristem [27].…”