Colletotrichum higginsianum (Ch) is a typical hemibiotrophic ascomycetous fungus. The diseases it causes often lead to considerable economic losses in global cruciferous crop production. However, current knowledge is still insufficient for us to gain a deeper understanding of how host plants respond at the transcriptional level during Ch infection. Herein, we performed transcriptomic and metabolic assays between Mock and Ch- infected samples. The results showed that Ch infection significantly inhibited the shoot fresh weight and primary root length of host plants. Furthermore, gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to phenylpropanoid metabolism were highly enriched. Defense hormone salicylic acid (SA) and three metabolites belonging to the phenylpropanoid metabolism pathway were identified. Meanwhile, we screened 5 related enzyme-encoding genes and 78 transcription factors (TFs). Five WRKY, three MYB, and two NAC TFs showed significant expression changes and high correlation with enzyme genes. Our results enrich regulatory networks in crucifier pathogen responses. This work provides potential molecular candidates to support subsequent studies on the mechanisms underlying Ch resistance.
Hong Ye, Qi-Wen Gao, Yong-Jian Zou et al.· Life· 0 citations
Perilla (Perilla frutescens) is an important oil-bearing crop rich in α-linolenic acid (ALA), and seed oil quality varies greatly among different germplasms. However, the molecular and metabolic mechanisms underlying genotypic differences in ALA accumulation remain unclear. In this study, four Perilla varieties with distinct seed phenotypic traits were used to investigate the variations in seed quality, metabolome, and transcriptome. Significant genotypic differences were observed in seed color, thousand-grain weight, and oil content. QO8 showed the highest seed oil content, while QS5 and QO10 exhibited relatively lower oil accumulation levels. Metabolome analysis revealed that lipid metabolism was the dominant metabolic category in Perilla seeds. Multiple differentially accumulated metabolites (DAMs), including ALA, stearic acid, traumatic acid, and 10-OPDA, displayed genotype-specific accumulation patterns. KEGG enrichment demonstrated that α-linolenic acid metabolism and unsaturated fatty acid biosynthesis were the most significantly divergent pathways among different Perilla germplasms. Transcriptome analysis identified numerous differentially expressed genes (DEGs) involved in fatty acid and ALA biosynthesis, such as FAD2, LOX, AOS, AOC, OPR, KAT, ECH, and ACOX. Integrated transcriptome and metabolome analysis further confirmed that the differential expression of structural genes altered the metabolic flux of the ALA and downstream jasmonic acid pathway, resulting in varied accumulation of core lipid intermediates. In addition, WRKY and MYB transcription factors were identified as key upstream regulators that positively or negatively modulated ALA metabolic homeostasis. This study systematically clarified the phenotypic, metabolic, and transcriptional differences in seeds of different Perilla varieties and revealed the core regulatory network of ALA biosynthesis. These findings provide valuable candidate genes and a theoretical foundation for elucidating the molecular mechanism of high ALA accumulation and quality improvement in Perilla seeds.
