New insight into ovary abortion during ovary development of hazelnut through a combined proteomic and transcriptomic analysis

Hazel (Corylus spp.) is the most economically important species in the Betulaceae family. Frequent ovary abortion during the prefertilization stage causes the high drop ratio of pistillate flowers and smaller fruit numbers in a fruit cluster, resulting in yield loss. To better understand the mechanism of ovary abortion formation in hazel, we conducted transcriptomic and proteomic analyses and identified genes and proteins that were altered in response to ovary abortion. A total of 89,846 unigenes and 4343 proteins were identified using RNA-seq and iTRAQ technology, respectively. Among them, 1895 unigenes and 710 proteins were differentially expressed and accumulated in the developing and abortive ovary respectively. Furthermore, we employed the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, revealing pathways that are significantly enriched in both transcriptomic and proteomic assays. These include the phenylalanine metabolic pathway, biosynthesis of phenylpropanoid, biosynthesis of secondary metabolites, and ascorbate and aldarate metabolism. Transcriptome-proteome integrative analysis revealed 42 correlations. Among these, 32 correlations with same changing trend (that are involved in metabolism stress response, vascular strand development, water transport, and seed development) are likely associated with abortive ovary formation. Importantly, ethylene (ETH), jasmonic acid (JA), and salicylic acid (SA) signal transduction pathways may contribute to the regulation of the abortive ovary formation via the up-regulation of ethylene-responsive transcription factor 1 (ERF1/2), jasmonate ZIM domain-containing protein (JAZ), transcription factor MYC2 (MYC2), transcription factor (TGA), and pathogenesis-related protein 1(PR-1). Our work will facilitate the identification of ovary abortion related genes and proteins and provide insights into the molecular mechanism of fruit development.