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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. [ABSTRACT FROM AUTHOR]

Abstract: The infection of the model legume Medicago truncatula with Ralstonia solanacearum GMI1000 gives rise to bacterial wilt disease via colonisation of roots. The root and leaf responses to early infection (1 and 3 days post infection) were characterised to investigate the molecular mechanisms of plant resistance or susceptibility. A proteomics approach based on pools of susceptible and resistant recombinant inbred lines was used to specifically target the mechanisms for tolerance. Differential abundances were evidenced for proteins involved in defence (e.g., PR5, PR10, or Kunitz protease inhibitors) and signalling pathways (such as cyclophilin). R. solanacearum inoculation modifies expression levels of those genes, either in both genotypes (AOS1, LOX4, and proteinase inhibitors) or specifically in the resistant line (PR proteins). Exogenous application of salicylic acid (SA) enhanced tolerance to the bacteria, whereas methyl jasmonate (MeJA) enhanced short‐term tolerance then promoted disease in the susceptible ecotype, suggesting that they may mediate defence responses. Conversely, proteomics‐identified genes were also shown to be SA or MeJA responsive. This is the first description of differential response to R. solanacearum in M. truncatula. Our results suggest that root basal defence is activated at 1 dpi, together with the JA pathway. Specific resistance is then evidenced at three dpi, with the up‐regulation of SA‐dependent PR proteins. [ABSTRACT FROM AUTHOR]