Summary MicroRNAs (miRNAs) are essential regulators of gene expression in metazoans and plants. In plants, most miRNAs are generated from primary miRNA transcripts (pri‐miRNAs), which are processed by the Dicer‐like 1 (DCL1) complex along with accessory proteins.Serrate‐Associated Protein 1 (SEAP1), a conserved splicing‐related protein, has been studied in human and yeast. However, the functions of SEAP1 in plants remain elusive.Lack ofSEAP1results in embryo lethality and knockdown ofSEAP1by an artificial miRNA (amiRSEAP1) causes pleiotropic developmental defects and reduction in miRNA accumulation. SEAP1 associates with the DCL1 complex, and may promote the interaction of the DCL1 complexes with pri‐miRNAs. SEAP1 also enhances pri‐miRNA accumulation, but does not affect pri‐miRNA transcription, suggesting it may indirectly or directly stabilize pri‐miRNAs. In addition, SEAP1 affects the splicing of some pri‐miRNAs and intron retention of messenger RNAs at global levels.Our findings uncover both conserved and novel functions of SEAP1 in plants. Besides the role as a splicing factor, SEPA1 may promote miRNA biogenesis by positively modulating pri‐miRNA splicing, processing and/or stability.
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Hairpin in a haystack : In silico identification and characterization of plant-conserved microRNA in Rafflesiaceae
Abstract Rafflesiaceae is a family of endangered plants whose members are solely parasitic to the tropical grape vineTetrastigma(Vitaceae). Currently, the genetics of their crosstalk with the host remains unexplored. In this study, we use homology-basedin silicoapproaches to characterize micro-RNAs (miRNAs) expressed bySapria himalayanaandRafflesia cantleyifrom published omics data. Derived from secondary structures or hairpins, miRNAs are small regulators of gene expression. We found that some plant-conserved miRNA still exists in Rafflesiaceae. Out of 9 highly conserved miRNA families in plants, 7 families (156/157, 159/319, 160, 165/166, 171, 172, 390) were identified with a total of 22 variants across Rafflesiaceae. Some miRNAs were missing endogenous targets and may have evolved to target host miRNA, though this requires experimental verification. Rafflesiaceae miRNA promoters are mostly inducible by ethylene that mediates stress response in the host but could be perceived by the parasites as a signal for growth. This study provides evidence that certain miRNAs with ancient origins in land plants still exist in Rafflesiaceae, though some may have been coopted by parasites to target host genes.
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- Award ID(s):
- 2346626
- PAR ID:
- 10582394
- Publisher / Repository:
- deGruyter
- Date Published:
- Journal Name:
- Open Life Sciences
- Volume:
- 20
- Issue:
- 1
- ISSN:
- 2391-5412
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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