Comparative transcriptome analysis reveals regulatory network and regulators associated with proanthocyanidin accumulation in persimmon

Abstract

Background Proanthocyanidins (PAs) are important plant secondary metabolites that confer flavor, nutritional value, and resistance to pathogens. Persimmon is one of the PA richest crops. Mature fruits can be inedible because of the astringency caused by high PA levels and need to go through a de-astringency treatment before consumption. The molecular basis for PA accumulation is poorly known, particularly transcriptional regulators. We characterised three genotypes (‘Luotiantianshi’ (LT), ‘Mopanshi’ (MP), and ‘Youhou’ (YH)) with different PA accumulation patterns using an approach that combined PacBio full-length sequencing and Illumina-based RNA sequencing to build high-quality full-length transcriptomes. Additionally, we analysed transcriptome dynamics of the three genotypes (LT, MP, and YH) at four key fruit developmental stages. Results A total of 96,463 transcripts were obtained. We identified 80,075 protein-coding sequences (CDSs), 71,137 simple sequence repeats (SSRs), and 27,845 long noncoding RNAs (lncRNAs). Pearson correlation coefficient (PCC), principal component analysis (PCA), and differentially expressed transcripts (DETs) analyses indicated that the four different developmental stages within a genotype exhibited similar transcriptome activities. A total of 2,164 transcripts specific to each fruit developmental stage were detected. The transcripts specific to early stages were attributed to phenylpropanoid and flavonoid biosynthesis. Co-expression network analyses revealed MEbrown and MEblue modules were strongly associated to PA accumulation. From these two modules, 20 hub TFs are potential regulators for PA accumulation. Among them, Cluster_78388 (SBP protein), Cluster_63454 (bZIP protein), and Cluster_66595 (MYB protein) appear to involve in the PA biosynthesis in Chinese genotypes. Conclusions This is the first high-quality reference transcriptome for commercial persimmon. Our work provides insights into the molecular pathways underlying PA accumulation and enhances our global understanding of transcriptome dynamics throughout fruit development.

Comparative Transcriptome and Phytochemical Analysis Provides Insight into Triterpene Saponin Biosynthesis in Seeds and Flowers of the Tea Plant (Camellia sinensis)

“…The theoretical basis for the synthesis and accumulation of saponins in different tissues of tea plants is still not clear. With the development of high-throughput sequencing (HTS) technologies, the synthetic pathways of many secondary metabolites in varieties of plants have been elucidated [ 16 , 17 ]. In this study, the saponin content of tea leaves, flowers and seeds in different growth periods was determined.…”

Metabolome and transcriptome profiling reveal regulatory network and mechanism of flavonoid biosynthesis during color formation of Dioscorea cirrhosa L.

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Reinforcing the bulwark: unravelling the efficient applications of plant phenolics and tannins against environmental stresses

“…Certain fruits, such as the persimmon, have both high- and low-CT varieties. Low-tannin fruits stop generating CTs at a primary stage of growth, whereas tannin-rich fruits accumulate them until they are fully matured, imparting an unpleasant flavor ( Zheng et al., 2021 ). Despite a wealth of research on the compounds and amounts of tannins in commercially important fruits, only a few species have been studied to see how they change as the fruit matures.…”