Identification of miRNAs-mediated seed and stone-hardening regulatory networks and their signal pathway of GA-induced seedless berries in grapevine (V. vinifera L.)

Characterization of VvmiR166s-Target Modules and Their Interaction Pathways in Modulation of Gibberellic-Acid-Induced Grape Seedless Berries

Exogenous GA is widely used to efficiently induce grape seedless berry development for significantly improving berry quality. Recently, we found that VvmiR166s are important regulators of response to GA in grapes, but its roles in GA-induced seedless grape berry development remain elusive. Here, the precise sequences of VvmiR166s and their targets VvREV, VvHB15 and VvHOX32 were determined in grape cv. 'Rosario Bianco', and the cleavage interactions of VvmiR166s-VvHB15/VvHOX32/VvREV modules and the variations in their cleavage roles were confirmed in grape berries. Exogenous GA treatment significantly induced a change in their expression correlations from positive to negative between VvmiR166s and their target genes at the seeds during the stone-hardening stages (32 DAF-46 DAF) in grape berries, indicating exogenous GA change action modes of VvmiR166s on their targets in this process, in which exogenous GA mainly enhanced the negative regulatory roles of VvmiR166s on VvHB15 among all three VvmiR166s-target pairs. The transient OE-VvmiR166a-h/OE-VvHB15 in tobacco confirmed that out of the VvmiR166 family, VvmiR166h/a/b might be the main factors in modulating lignin synthesis through inhibiting VvHB15, of which VvmiR166h-VvHB15-NtPAL4/NtCCR1/NtCCR2/NtCCoAMT5/NtCOMT1 and VvmiR166a/b-VvHB15-NtCAD1 are the potential key regulatory modules in lignin synthesis. Together with the GA-induced expression modes of VvmiR166s-VvHB15 and genes related to lignin synthesis in grape berries, we revealed that GA might repress lignin synthesis mainly by repressing VvCAD1/VvCCR2/VvPAL2/VvPAL3/Vv4CL/VvLac7 levels via mediating VvmiR166s-VvHB15 modules in GA-induced grape seedless berries. Our findings present a novel insight into the roles of VvmiR66s that are responsive to GA in repressing the lignin synthesis of grape seedless berries, with different lignin-synthesis-enzyme-dependent action pathways in diverse plants, which have important implications for the molecular breeding of high-quality seedless grape berries.

Regulatory of miRNAs in tri-lineage differentiation of C3H10T1/2

MicroRNAs (miRNAs) are non-coding single-stranded RNA molecules encoded by endogenous genes, which play a vital role in cell generation, metabolism, apoptosis and stem cell differentiation. C3H10T1/2, a mesenchymal cell extracted from mouse embryos, is capable of osteogenic differentiation, adipogenic differentiation and chondrogenic differentiation. Extensive studies have shown that not only miRNAs can directly trigger targeted genes to regulate the tri-lineage differentiation of C3H10T1/2, but it also can indirectly regulate the differentiation by triggering different signaling pathways or various downstream molecules. This paper aims to clarify the regulatory roles of different miRNAs on C3H10T1/2 differentiation, and discussing their balance effect among osteogenic differentiation, adipogenic differentiation and chondrogenic differentiation of C3H10T1/2. We also review the biogenesis of miRNAs, Wnt signaling pathways, MAPK signaling pathways and BMP signaling pathways and provide some specific examples of how these signaling pathways act on C3H10T1/2 tri-lineage differentiation. On this basis, we hope that a deeper understanding of the differentiation and regulation mechanism of miRNAs in C3H10T1/2 can provide a promising therapeutic method for the clinical treatment of bone defects, osteoporosis, osteoarthritis and other diseases.

Identification and verification of seed development related miRNAs in kernel almond by small RNA sequencing and qPCR

Many studies have investigated the role of miRNAs on the yield of various plants, but so far, no report is available on the identification and role of miRNAs in fruit and seed development of almonds. In this study, preliminary analysis by high-throughput sequencing of short RNAs of kernels from the crosses between almond cultivars 'Sefid' × 'Mamaee' (with small and large kernels, respectively) and 'Sefid' × 'P. orientalis' (with small kernels) showed that the expressions of several miRNAs such as Pdu-miR395a-3p, Pdu-miR8123-5p, Pdu-miR482f, Pdu-miR6285, and Pdu-miR396a were significantly different. These miRNAs targeted genes encoding different proteins such as NYFB-3, SPX1, PGSIP3 (GUX2), GH3.9, and BEN1. The result of RT-qPCR revealed that the expression of these genes showed significant differences between the crosses and developmental stages of the seeds, suggesting that these genes might be involved in controlling kernel size because the presence of these miRNAs had a negative effect on their target genes. Pollen source can influence kernel size by affecting hormonal signaling and metabolic pathways through related miRNAs, a phenomenon known as xenia.