Project description:For tree crops, shortening juvenile phase is a vital strategy for early flowering that ensure to bear fruits in advance to enhance breeding efficiency. In walnut (Juglans regia L.), it usually takes 3-5 years for blooming, but the early flowering (EF) walnut can even flower in a year after planted. The juvenile phase of EF walnut is shorter than the late flowering (LF) walnut, which is more propitious to breeding efficiency. In this study, using RNA sequencing (RNA-seq) and microRNA-seq, we profiled transcriptome-wide identification of gene expression and microRNAs between EF and LF walnuts.
Project description:Walnut (Juglans regia L.) is an important nut fruit crop mainly grown for its high nutritional and medicinal value. In walnut fruit, the pellicle is the main source of polyphenols (such as proanthocyanidins), which are natural bioactive compounds but also cause astringency and bitterness for walnut fruit consumption. However, the gene regulatory networks of phenolic biosynthetic pathways remain largely unknown in walnut pellicles. Here, we performed RNA sequencing (RNA-seq) to identify differentially expressed genes (DEGs) associated with pellicle development in walnut. In this study, seven developmental stages (8-, 9-, 11-, 13-, 15-, 17-, and 19-week after pollination) of ‘Xinwen179’ pellicle tissues were harvested to conduct further transcriptome-wide profiles. Via RNA-seq, we explored several key DEGs involved in the phenolic biosynthetic pathway, such as dihydroflavonol-4-reductase (DFR), leucoanthocyanidin reductase (LAR), anthocyanidin synthase (ANS) and anthocyanidin reductase (ANR), which are dynamically expressed at developmental stages of the walnut pellicle. Taken together, our preliminary investigation on DEGs associated with pellicle development will not only elucidate the gene regulatory networks of the phenolic biosynthetic pathway for pellicle development, but also contribute to the broad spectrum of RNA-seq data resources for further genetic improvement of walnut.