Abstract
The breeding of new soft-seeded pomegranate cultivars provides new products for the market and increases farmers’ incomes, yet the genetic architecture mediating seed hardness is largely unknown. Here, the seed hardness and hundred-seed weights of 26 cultivars were determined in 2 successive years. We conducted miRNA and mRNA sequencing to analyse the seeds of two varieties of Punica granatum: soft-seeded Tunisia and hard-seeded Sanbai, at 60 and 120 d after flowering. Seed hardness was strongly positively correlated with hundred-seed weight. We detected 25 and 12 differentially expressed miRNA–mRNA pairs with negative regulatory relationships between the two genotypes at 60 and 120 d after flowering, respectively. These miRNA–mRNA pairs mainly regulated seed hardness by altering cell wall structure. Transcription factors including NAC1, WRKY and MYC, which are involved in seed hardness, were targeted by differentially expressed mdm-miR164e and mdm-miR172b. Thus, seed hardness is the result of a complex biological process regulated by a miRNA–mRNA network in pomegranate. These results will help us understand the complexity of seed hardness and help to elucidate the miRNA-mediated molecular mechanisms that contribute to seed hardness in pomegranate.
Highlights
Pomegranate is an edible fruit that is native to central Asia[1]
We used psRobot[14] and TargetFinder[15] with position-dependent scoring systems to predict the miRNA targets. These analyses identified 2,646 putative targets; 2,016 miRNA–mRNA pairs identified by psRobot and 1,795 pairs identified by TargetFinder, with 1,165
We found that these miRNAs suppressed vital targets, which included genes encoding transcription factors (TFs) and enzymes involved in the early stages of seed development, as well as proteins involved in storage compound synthesis and transport in the mature seeds
Summary
Pomegranate is an edible fruit that is native to central Asia[1]. It has gained attention because of its antioxidant properties that have health benefits for humans and protect against several diseases such as hypertension cardiovascular and cancer[2]. Our previous study showed that the seed hardness increased from 60 to 120 d after flowering (DAF) in hard-seeded varieties, but did not change during this period in soft-seeded varieties The latter had lower lignin contents than the former[4]. We conducted deep-sequencing and bioinformatics analysis of seeds at 60 and 120 DAF to identify pomegranate-specific miRNAs, and to determine their expression patterns, in two varieties of P. granatum: soft-seeded Tunisia and hard-seeded Sanbai. The identification of these differentially expressed miRNAs–mRNAs provides new insights into the genetic mechanism of seed hardness in pomegranate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
