Integrative Analysis of the Identified Transcriptome and Proteome Major Metabolism Pathways Involved in the Development of Grafted Apricot Hybrids

Abstract

Plant distant grafting can produce stable genetic variation, which is a new method for germplasm innovation. Two chimeras, peach/apricot (PA) and apricot/peach (AP), were created through two-way grafting between peach and apricot. The leaves, flowers and fruit phenotypes of chimeras were significantly different to self-rooted rootstock. In order to investigate the causes of such changes, transcriptome and proteome integrative analyses were conducted on apricots from these two chimeras. Many differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) that may be connected to the development of grafted apricot hybrids were identified and explored based on function. Moreover, we found 76 genes in forward-grafted PA and 46 in reverse-grafted AP that overlapped both in DEGs and DEPs (DEGs/DEPs) via transcriptome–proteome integrative analysis. Mapping the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database in PA and AP, the top significant enrichment pathways of DEGs/DEPs included lipid metabolism (fatty acid elongation, cutin, suberine and wax biosynthesis, fatty acid degradation and alpha-linolenic acid metabolism) and carbohydrate metabolism (glycolysis/gluconeogenesis, starch and sucrose metabolism and galactose metabolism), revealing that lipid metabolism and carbohydrate metabolism may play an irreplaceable role in the development of grafted apricot hybrids. Taken together, this work uncovered numerous candidate transcripts and proteins involved in the development of grafted apricot hybrids. The molecular mechanisms provide new insights into this important process in other heterografting hybrids.