Gene expression and evidence of coregulation of the production of some metabolites of chilli pepper inoculated with Pectobacterium carotovorum ssp. carotovorum

Identification of HQT gene family and their potential function in CGA synthesis and abiotic stresses tolerance in vegetable sweet potato

Hydroxycinnamate-CoA quinate hydroxycinnamoyl transferase (HQT) enzyme affect plant secondary metabolism and are crucial for growth and development. To date, limited research on the genome-wide analysis of HQT family genes and their regulatory roles in chlorogenic acid (CGA) accumulation in leafy vegetable sweet potato is available. Here, a total of 58 HQT family genes in the sweet potato genome (named IbHQT) were identified and analyzed. We studied the chromosomal distribution, phylogenetic relationship, motifs distribution, collinearity, and cis-acting element analysis of HQT family genes. This study used two sweet potato varieties, high CGA content Fushu 7-6-14-7 (HC), and low CGA content Fushu 7-6 (LC). Based on the phylogenetic analysis, clade A was unique among the identified four clades as it contained HQT genes from various species. The chromosomal location and collinearity analysis revealed that tandem gene duplication may promote the IbHQT gene expansion and expression. The expression patterns and profile analysis showed changes in gene expression levels at different developmental stages and under cold, drought, and salt stress conditions. The expression analysis verified by qRT-PCR revealed that IbHQT genes were highly expressed in the HC variety leaves than in the LC variety. Furthermore, cloning and gene function analysis unveiled that IbHQT family genes are involved in the biosynthesis and accumulation of CGA in sweet-potato. This study expands our understanding of the regulatory role of HQT genes in sweet-potato and lays a foundation for further functional characterization and genetic breeding by engineering targeted HQT candidate genes in various sweet-potato varieties and other species.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01299-4.

Metabolite profile of African horned cucumber (Cucumis metuliferus E. May. Ex Naudin) fruit grown under differing environmental conditions

Plant metabolites are known as biological compounds that are essential to the growth and development of a plant and have a direct impact on yield and biochemical constituents of plants. For this study, the objective was to conduct primary metabolomics analysis using liquid chromatography mass spectrometry. African horned cucumber fruits were harvested from plants grown under pots experiment (greenhouse, shade net and open field), soil types (loamy soil and sandy loam) and three water stress levels (no water stress-100%-3L, moderate water stress-75%-2L, and severe water stress-35%-1L) during 2017/18 and 2018/19 seasons. Results showed that the treatment of no water stress combined with sandy loam under shade net environment, significantly increased asparagine content from 10 × 10⁶ to 80 × 10⁶ peak intensity. The treatment of no water stress, in combination with sandy loam soil under open field environment increased 4-hydroxyproline from 10 × 10⁶ to 90 × 10⁶ peak intensity compared to other treatments. It can be deduced that the treatment combination of (no water stress and moderate water stress) and all soil types, under greenhouse environment increased most metabolites content of the fruit when compared to other treatments. Therefore, it subsequently has potential to affect fruit quality such as taste and other biochemical constituents.

LC-MS Based Metabolomics Analysis of Potato (Solanum tuberosum L.) Cultivars Irrigated with Quicklime Treated Acid Mine Drainage Water

In water-scarce areas, the reuse of (un)treated acid mine drainage (AMD) water for crop irrigation has become a requirement, but it also carries a wide range of contaminants that can elicit the synthesis of diverse metabolites necessary for the survival of the plants. There is still a paucity of studies on the impact of quicklime treated-AMD water on the metabolite synthesis of potatoes. This study examined the effect of the irrigation of two potato cultivars (Marykies and Royal cultivars) with quicklime-treated AMD water on their metabolite profiles. A greenhouse study was conducted with five experimental treatments with different solution ratios, replicated three times in a completely randomized design. A total of 40 and 36 metabolites from Marykies and Royal cultivars which include amino acids, organic acids, and aromatic amines were identified, respectively. The results revealed elevation in the abundance of metabolites under the irrigation with treated AMD water for both cultivars with subtle variations. This will provide information on the primary metabolite shifst in potato that enhance their survival and growth under AMD conditions. However, more specific data on toxicity due to AMD irrigation would be required for a refined risk assessment.

Integrated Analysis of Metabolome and Transcriptome Reveals Insights for Cold Tolerance in Rapeseed (Brassica napus L.)

Rapeseed (Brassica napus L.) is an important oilseed crop in the world. Its productivity is significantly influenced by numerous abiotic stresses, including cold stress (CS). Consequently, enhancement in CS tolerance is becoming an important area for agricultural investigation and crop improvement. Therefore, the current study aimed to identify the stress-responsive genes, metabolites, and metabolic pathways based on a combined transcriptome and metabolome analysis to understand the CS responses and tolerance mechanisms in the cold-tolerant (C18) and cold-sensitive (C6) rapeseed varieties. Based on the metabolome analysis, 31 differentially accumulated metabolites (DAMs) were identified between different comparisons of both varieties at the same time points. From the transcriptome analysis, 2,845, 3,358, and 2,819 differentially expressed genes (DEGs) were detected from the comparison of C6-0 vs. C18-0, C6-1 vs. C18-1, and C6-7 vs. C18-7. By combining the transcriptome and metabolome data sets, we found that numerous DAMs were strongly correlated with several differentially expressed genes (DEGs). A functional enrichment analysis of the DAMs and the correlated DEGs specified that most DEGs and DAMs were mainly enriched in diverse carbohydrates and amino acid metabolisms. Among them, starch and sucrose metabolism and phenylalanine metabolism were significantly enriched and played a vital role in the CS adaption of rapeseed. Six candidate genes were selected from the two pathways for controlling the adaption to low temperature. In a further validation, the T-DNA insertion mutants of their Arabidopsis homologous, including 4cl3, cel5, fruct4, ugp1, axs1, and bam2/9, were characterized and six lines differed significantly in levels of freezing tolerance. The outcome of the current study provided new prospects for the understanding of the molecular basis of CS responses and tolerance mechanisms in rapeseed and present a set of candidate genes for use in improving CS adaptability in the same plant.