High temperature increased lignin contents of poplar (Populus spp) stem via inducing the synthesis caffeate and coniferaldehyde

Abstract

Lignin contributes to plant resistance to biotic and abiotic stresses and is dominantly regulated by enzymes which catalyze the generation of metabolites intermediates in lignin synthesis. However, the response of lignin and its key regulatory factors to high temperature stress are poorly understood. Here, this finding revealed that the content of lignin in poplar (Populus spp) stem increased after 3 days of high temperature stress treatment. In fourteen metabolic intermediates of lignin biosynthetic pathway with targeted metabolomics analysis, caffeate and coniferaldehyde increased evidently upon heat stress. C3’H (p-Coumaroylshikimate 3-hydroxylase) and CCR (Cinnamoyl-CoA reductase) are recognized to catalyze the formation of caffeate and coniferaldehyde, respectively. Transcriptome data and RT-qPCR (reverse transcription-quantitative real-time polymerase chain reaction) analysis uncovered the high transcriptional level of PtrMYBs (PtrMYB021, PtrMYB074, PtrMYB85, PtrMYB46), PtrC3’H1 (Potri.006G033300) and PtrCCR2 (Potri.003G181400), suggesting that they played the vital role in the increase of lignin and its metabolic intermediates were induced by high temperature. The discovery of key regulators and metabolic intermediates in lignin pathway that respond to high temperature provides a theoretical basis for quality improvement of lignin and the application of forest resources.

Integrated physiological, metabolomic, and transcriptomic analyses elucidate the regulation mechanisms of lignin synthesis under osmotic stress in alfalfa leaf (Medicago sativa L.)

“…There are many intermediate metabolites involved in the lignin synthesis process. Previous research has pointed out that the content of these intermediate metabolites changes under abiotic stress [ 24 ]. Seven DAMs involved in lignin synthesis increased remarkably under salt stress in the root tissue of Sophora alopecuroides , including phenylalanine, cinnamic acid, ferulic acid, cinnamaldehyde, caffeylaldehyde, sinapyl alcohol, and coniferin [ 25 ].…”

Distinct heat response molecular mechanisms emerge in cassava vasculature compared to leaf mesophyll tissue under high temperature stress

“…This facilitates the efficient long-distance transport of water, minerals, and organic matter within the plant. For instance, poplar increased the lignin biosynthesis in stem to cope with HT stress ( Zhao et al., 2022 ). In the transcriptome results of vascular bundle, phenylalanine metabolism pathway was significantly enriched in the HT treated group.…”

Temperature‐smart plants: A new horizon with omics‐driven plant breeding

“…In another study, intermediates of the lignin biosynthetic pathway, including caffeate and coniferaldehyde, increased in Populus spp. after exposure to HS (35°C) for 3 days (Zhao et al, 2022b). A study on tobacco revealed increased levels of sugars (sedoheptulose and sucrose) and non‐codogenic amino acids (pipecolate and c‐amino butyrate) at 22 and 37 °C, respectively (Krawczyk et al, 2022).…”