Project description:Background Field observations and a few physiological studies pointed out that peach embryogenesis and fruit development are strictly related. In fact, attempts to stimulate parthenocarpic fruit development by means of external tools failed. Moreover, physiological disturbances during the early embryo development lead to seed abortion and fruitlet abscission. Later on, the interactions between seed and fruit development become less stringent. Genetic and molecular information about seed and fruit development in peach is limited. Results The isolation of 455 genes differentially expressed in seed and fruit was done by means of a comparative analysis of the transcription profiles carried out in peach (Prunus persica, cv Fantasia) seed and mesocarp throughout development by means of µPEACH 1.0, the first peach microarray. Genes differentially expressed in the two organs and specific of developmental stages had been identified, and some were validated as markers. Genes representative of the main functional categories are present, among which several transcription factors such as MADS-box, bZIP, Aux/IAA, AP2, WRKY, and HD. Some of these showed a similar transcription profile in the two organs, while others displayed an opposite pattern, being more expressed in embryo at early development and in mesocarp at ripening. Conclusions The µPEACH1.0, although developed from ripe fruit ESTs, resulted in being suitable for studying seed/mesocarp interactions. Among the differentially expressed genes, marker genes specific for organ and stage of development have been selected. Comparisons were carried out by pooling stage 1 and 2 (named early development, e) and stage 3 and 4 (named late development, l), separately for mesocarp (M) and seed (S) of cultivar Fantasia, and using a simple loop experimental design. RNA has been extracted from fruit harvest at above-mentioned stages of development. At least four hybridizations have been conducted for a total of four technical replicates (with dye-swap).
Project description:Background Field observations and a few physiological studies pointed out that peach embryogenesis and fruit development are strictly related. In fact, attempts to stimulate parthenocarpic fruit development by means of external tools failed. Moreover, physiological disturbances during the early embryo development lead to seed abortion and fruitlet abscission. Later on, the interactions between seed and fruit development become less stringent. Genetic and molecular information about seed and fruit development in peach is limited. Results The isolation of 455 genes differentially expressed in seed and fruit was done by means of a comparative analysis of the transcription profiles carried out in peach (Prunus persica, cv Fantasia) seed and mesocarp throughout development by means of µPEACH 1.0, the first peach microarray. Genes differentially expressed in the two organs and specific of developmental stages had been identified, and some were validated as markers. Genes representative of the main functional categories are present, among which several transcription factors such as MADS-box, bZIP, Aux/IAA, AP2, WRKY, and HD. Some of these showed a similar transcription profile in the two organs, while others displayed an opposite pattern, being more expressed in embryo at early development and in mesocarp at ripening. Conclusions The µPEACH1.0, although developed from ripe fruit ESTs, resulted in being suitable for studying seed/mesocarp interactions. Among the differentially expressed genes, marker genes specific for organ and stage of development have been selected.
Project description:We performed small RNA deep sequencing and identified 47 peach-specific and 47 known miRNAs or families with distinct expression patterns. Together, the identified miRNAs targeted 80 genes, many of which have not been reported previously. Like the model plant systems, peach has two of the three conserved trans-acting siRNA biogenesis pathways with similar mechanistic features and target specificity. Unique to peach, three of the miRNAs collectively target 49 MYBs, 19 of which are known to regulate phenylpropanoid metabolism, a key pathway associated with stone hardening and fruit color development, highlighting a critical role of miRNAs in regulation of peach fruit development and ripening. We also found that the majority of the miRNAs were differentially regulated in different tissues, in part due to differential processing of miRNA precursors. Up to 16% of the peach-specific miRNAs were differentially processed from their precursors in a tissue specific fashion, which has been rarely observed in plant cells. The miRNA precursor processing activity appeared not to be coupled with its transcriptional activity but rather acted independently in peach. Collectively, the data characterizes the unique expression pattern and processing regulation of peach miRNAs and demonstrates the presence of a complex, multi-level miRNA regulatory network capable of targeting a wide variety of biological functions, including phenylpropanoid pathways which play a multifaceted spatial-temporal role in peach fruit development. Identification of peach miRNAs and their targets from four different tissues
Project description:We performed small RNA deep sequencing and identified 47 peach-specific and 47 known miRNAs or families with distinct expression patterns. Together, the identified miRNAs targeted 80 genes, many of which have not been reported previously. Like the model plant systems, peach has two of the three conserved trans-acting siRNA biogenesis pathways with similar mechanistic features and target specificity. Unique to peach, three of the miRNAs collectively target 49 MYBs, 19 of which are known to regulate phenylpropanoid metabolism, a key pathway associated with stone hardening and fruit color development, highlighting a critical role of miRNAs in regulation of peach fruit development and ripening. We also found that the majority of the miRNAs were differentially regulated in different tissues, in part due to differential processing of miRNA precursors. Up to 16% of the peach-specific miRNAs were differentially processed from their precursors in a tissue specific fashion, which has been rarely observed in plant cells. The miRNA precursor processing activity appeared not to be coupled with its transcriptional activity but rather acted independently in peach. Collectively, the data characterizes the unique expression pattern and processing regulation of peach miRNAs and demonstrates the presence of a complex, multi-level miRNA regulatory network capable of targeting a wide variety of biological functions, including phenylpropanoid pathways which play a multifaceted spatial-temporal role in peach fruit development.
Project description:MicroRNAs play critical roles in various biological and metabolic processes. The function of miRNAs has been widely studied in model plants such as Arabidopsis and rice. However, the number of identified miRNAs and related miRNA targets in peach (Prunus persica) is limited. To understand further the relationship between miRNAs and their target genes during tissue development in peach, a small RNA library and three degradome libraries were constructed from three tissues for deep sequencing. We identified 117 conserved miRNAs and 186 novel miRNA candidates in peach by deep sequencing and 19 conserved miRNAs and 13 novel miRNAs were further evaluated for their expression by RT-qPCR. The number of gene targets that were identified for 26 conserved miRNA families and 38 novel miRNA candidates, were 172 and 87, respectively. Some of the identified miRNA targets were abundantly represented as conserved miRNA targets in plant. However, some of them were first identified and showed important roles in peach development. Our study provides information concerning the regulatory network of miRNAs in peach and advances our understanding of miRNA functions during tissue development. To identify more conserved and peach-speciM-oM-,M-^Ac miRNAs and their target genes and to understand further the mechanism of miRNA-regulated target genes during tissue development in peach, a small RNA library and three degradome libraries were constructed from three different tissues for deep sequencing.
Project description:Fleshy fruit help in reproduction by developing structures that, reached a given maturity stage, become attractive to animals that, feeding on them, spread the contained seeds in the environment. According to the species, seed development can be at the same pace with the pericarp, or be ready for dispersion before or after the ripening of the fruit. In peach, seed and mesocarp maturation are on pace in mid-season cultivars, while in early ripening ones the seed is not mature at ripening, with the endosperm not yet fully reabsorbed. On the contrary, slow ripening genotypes show the opposite, i.e. a mature seed in a fruit unable to fully ripen. To gain insights on the molecular control of peach fruit development and ripening and on the interactions between the seed and the mesocarp, genome wide transcriptional changes of the two fruit parts have been investigated throughout development from flower anthesis up to commercial ripening in the mid-season cultivar Fantasia. Besides flower, six time points encompassing the four fruit developmental stages were investigated.
Project description:MicroRNAs play critical roles in various biological and metabolic processes. The function of miRNAs has been widely studied in model plants such as Arabidopsis and rice. However, the number of identified miRNAs and related miRNA targets in peach (Prunus persica) is limited. To understand further the relationship between miRNAs and their target genes during tissue development in peach, a small RNA library and three degradome libraries were constructed from three tissues for deep sequencing. We identified 117 conserved miRNAs and 186 novel miRNA candidates in peach by deep sequencing and 19 conserved miRNAs and 13 novel miRNAs were further evaluated for their expression by RT-qPCR. The number of gene targets that were identified for 26 conserved miRNA families and 38 novel miRNA candidates, were 172 and 87, respectively. Some of the identified miRNA targets were abundantly represented as conserved miRNA targets in plant. However, some of them were first identified and showed important roles in peach development. Our study provides information concerning the regulatory network of miRNAs in peach and advances our understanding of miRNA functions during tissue development.
Project description:Trees with weeping shoot architectures are valued for their beauty and are a resource for understanding how plants regulate posture control. The Prunus persica (peach) weeping phenotype, which has elliptical downward arching branches, is caused by a homozygous mutation in the WEEP gene. Until now, little was known about the function of WEEP protein despite its high conservation throughout Plantae. Here, we present the results of anatomical, biochemical, biomechanical, physiological, and molecular experiments that provide insight into WEEP function. Our data suggest that weeping peach trees do not have defects in branch structure. Rather, transcriptomes from the adaxial (upper) and abaxial (lower) sides of standard and weeping branch shoot tips revealed flipped expression patterns for genes associated with early auxin response, tissue patterning, cell elongation, and tension wood development. This suggests that WEEP promotes polar auxin transport toward the lower side during shoot gravitropic response, leading to cell elongation and tension wood development. In addition, weeping peach trees exhibited steeper root systems and faster lateral root gravitropic response. This suggests that WEEP moderates root gravitropism and is essential to establishing the set-point angle of lateral roots from the gravity vector. Additionally, size-exclusion chromatography indicated that WEEP proteins self-oligomerize, like other proteins with sterile alpha motif domains. Collectively, our results from weeping peach provide new insight into polar auxin transport mechanisms associated with gravitropism and lateral shoot and root orientation.