Physiological and comparative transcriptome analyses reveal the mechanisms underlying waterlogging tolerance in a rapeseed anthocyanin-more mutant

Abstract

Background Rapeseed (Brassica napus) is the second largest oil crop worldwide. It is widely used in food, energy production and the chemical industry, as well as being an ornamental. Consequently, it has a large economic value and developmental potential. Waterlogging is an important abiotic stress that restricts plant growth and development. However, little is known about the molecular mechanisms underlying waterlogging tolerance in B. napus. Results In the present study, the physiological changes and transcriptomes of germination-stage rapeseed in response to waterlogging stress were investigated in the B. napus cultivar ‘Zhongshuang 11’ (ZS11) and its anthocyanin-more (am) mutant, which was identified in our previous study. The mutant showed stronger waterlogging tolerance compared with ZS11, and waterlogging stress significantly increased anthocyanin, soluble sugar and malondialdehyde contents and decreased chlorophyll contents in the mutant after 12 days of waterlogging. An RNA-seq analysis identified 1370 and 2336 differently expressed genes (DEGs) responding to waterlogging stress in ZS11 and am, respectively. An enrichment analysis revealed that the DEGs in ZS11 were predominately involved in carbohydrate metabolism, whereas those in the am mutant were particularly enriched in plant hormone signal transduction and response to endogenous stimulation. In total, 299 DEGs were identified as anthocyanin biosynthesis-related structural genes (24) and regulatory genes encoding transcription factors (275), which may explain the increased anthocyanin content in the am mutant. A total of 110 genes clustered in the plant hormone signal transduction pathway were also identified as DEGs, including 70 involved in auxin and ethylene signal transduction that were significantly changed in the mutant. Furthermore, the expression levels of 16 DEGs with putative roles in anthocyanin accumulation and biotic/abiotic stress responses were validated by quantitative real-time PCR as being consistent with the transcriptome profiles. Conclusion This study provides new insights into the molecular mechanisms of increased anthocyanin contents in rapeseed in response to waterlogging stress, which should be useful for reducing the damage caused by waterlogging stress and for further breeding new rapeseed varieties with high waterlogging tolerance.

Tissue-Specific Transcriptome and Metabolome Analysis Reveals the Response Mechanism of Brassica napus to Waterlogging Stress

“…At present, transcriptomics has been widely used in the study of waterlogging tolerance of plants such as rapeseed, kiwifruit, alfalfa, and wheat, but metabolomics have rarely been used [ 19 , 20 , 21 , 22 ]. With the rapid development of modern molecular biology, the research on the mechanism of plant water resistance has reached the level of multi-omics research.…”

“…Waterlogging stress affects rapeseed germination, emergence, and seedling growth, causing phenotypic changes and physiological and metabolic activities [ 19 ] In this study, the phenotypes of rapeseed changed significantly after simulated waterlogging stress and field waterlogging stress. In the pot and field experiments, the leaves of waterlogging-intolerant G218 turned yellow or purple more seriously than those of the waterlogging-tolerant G230.…”

Effects of exogenous calcium and calcium inhibitor on physiological characteristics of winter rape (Brassica rapa) under low temperature stress

“…A total of 54 pots were used to plant each variety, with 3 seedlings kept in each pot. Seedlings were subjected to stress treatment at the ve-leaf stage [19] .…”

Plant Disease Resistance-Related Signaling Pathways: Recent Progress and Future Prospects

“…ET plays an important regulatory role in many physiological processes of plants, from seed germination to senescence [104]. ET biosynthesis is regulated by many factors, including developmental and environmental factors [105]. There are five ET membranebinding receptors in Arabidopsis, ETR1, ETR2, ERS1, ERS2, and EIN4, which can transmit signals to downstream effectors.…”