Metabolomics Data Revealed Metabolite Changes during Endocarp Lignification in Kernel-Using Apricot

Abstract

To understand the metabolite dynamics and genetic regulatory mechanism of apricot shell, a typical endocarp, before and after lignification are unknown, we investigated the metabolite differences of the endocarp of ‘Youyi,’ a popular kernel-using apricot cultivar, using ultra-performance liquid chromatography tandem mass spectrometry strategy. The endocarp thickness increased rapidly from 8 to 37 days after flowering (DAF) and lignin deposition began at 37 DAF. In total, 626 non-volatile metabolites were obtained from the endocarp tissues before (33 DAF) and after (41 and 45 DAF) lignification. The relative sugar and organic acid contents decreased continuously and those of L-phenylalanine and L-tyrosine increased after lignification. In the non-lignified endocarp, the phenylpropanoid metabolites were mainly in the form of p-coumaric acid, ferulic acid, neochlorogenic acid, dicumarol, coniferin, and some lignans. After lignification, the metabolites were mainly in the form of glycoside lignin or lactone coumarins, and the relative contents of L-asarinin and forsythin increased. The results of transcriptome confirmed the upregulation of genes related to lignin biosynthesis, including β-glucosidase and coniferyl-alcohol glucosyltransferase and laccases, accelerated lignification. This study provides insights into the formation of lignified endocarp in a kernel-using apricot and clarifies the role of monolignin transport and oxidative polymerization.

Re-sequencing and morphological data revealed the genetics of stone shell and kernel traits in apricot

“…We found locus qtnSTH_2.2 on Chr2 in the region of 7.59–9.45 Mb, which is related to multiple tandem genes associated with lignin synthesis and regulation, such as phenylalanine ammonia-lyase ( Pa02g07108.1 and Pa02g07109.1 ), tyramine N-feruloyltransferase ( Pa02g07115.1 and Pa02g07116.1 ), three caffeic acid 3-O-methyltransferase genes ( Pa02g07215.1 , Pa02g07216.1 , and Pa02g07217.1 ), and seven 3-hydroxyisobutyryl-CoA hydrolase genes. This result is consistent with the differences in expression at the transcriptional and metabolic levels ( Zhang et al., 2022a ). We still need to dissect trait-rich QTL regions and narrow QTL regions to reduce the number of candidate genes, and the development of marker-assisted selection tools with high accuracy and efficiency is necessary for kernel-using apricot breeding.…”

“…Apricots are widely cultivated in the Northern Hemisphere and can be classified as fresh-using, kernel-using, and ornamental apricots according to their utilization purpose. Because of their hardiness and cold and drought tolerance ( Zhang et al., 2022a ), kernel-using apricots are an economically important fruit tree species in arid areas. In China, the area and annual output of kernel-using apricots are approximately 957,000 hm² and 300,000 t, respectively.…”

LC–MS and GC–MS Metabolomics Analyses Revealed That Different Exogenous Substances Improved the Quality of Blueberry Fruits under Soil Cadmium Toxicity

“…In this study, ES treatments increased the expression of l -phenylalanine (the initial substrate for phenylpropanoid biosynthesis) and 4-hydroxycinnamate in blueberry fruits under Cd toxicity (Figure B), which may be the result of ESs promoting the production of phenolic metabolites to alleviate the oxidative damage of Cd toxicity to blueberry fruits . Coniferin, a downstream product of cinnamic acid, plays an important role in pericarp lignification and response to abiotic stress . Our results showed that ES treatments significantly elevated coniferin levels in blueberry fruits under Cd toxicity.…”

“…53 Coniferin, a downstream product of cinnamic acid, plays an important role in pericarp lignification and response to abiotic stress. 54 Our results showed that ES treatments significantly elevated coniferin levels in blueberry fruits under Cd toxicity. Besides, ESs also significantly up-regulated the expression of Spd (Figure 4B), which, as an important amino acid metabolite involved in the phenylpropanoid biosynthesis, is closely related to antioxidant and anti-inflammatory bioactivities of fruits.…”

Contribution of the LAC Genes in Fruit Quality Attributes of the Fruit-Bearing Plants: A Comprehensive Review

“…Extensive research has been conducted on lignin biosynthesis pathways, and the enzymes involved have been extensively described [17,18]. Cytochrome P450 oxidoreductases, including (C4H), (C3H), and (F5H), are responsible for aromatic ring hydroxylation [15], while other monolignol biosynthetic enzymes, such as (PAL), (4CL), (HCT), (CSE), (CcOAMT), (CCR), (COMT), and (CAD), are present in the cytoplasm [19].…”