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Merino I, Guasca AO, Krmela A, Arif U, Ali A, Westerberg E, Jalmi SK, Hajslova J, Schulzova V, Sitbon F. Metabolomic and transcriptomic analyses identify external conditions and key genes underlying high levels of toxic glycoalkaloids in tubers of stress-sensitive potato cultivars. FRONTIERS IN PLANT SCIENCE 2023; 14:1210850. [PMID: 37860257 PMCID: PMC10582707 DOI: 10.3389/fpls.2023.1210850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 08/31/2023] [Indexed: 10/21/2023]
Abstract
Introduction High levels of toxic steroidal glycoalkaloids (SGAs) in potato tubers constitute a recognized food quality problem. Tuber SGA levels vary between potato cultivars and can increase after post-harvest stresses such as wounding and light exposure. A few cultivars, e.g., 'Magnum Bonum' and 'Lenape,' have been withdrawn from commercial sales due to excessive SGA levels during some cultivation years. However, these sudden SGA increases are diffucult to predict, and their causes are not understood. To identify external and genetic factors that underlie sudden SGA increases in certain potato cultivars, we have here in a 2-year study investigated 'Magnum Bonum' and five additional table potato cultivars for their SGA levels after wounding and light exposure. Results and methods Results showed that 'Magnum Bonum' has an unusual strong SGA response to light exposure, but not to wounding, whereas 'Bintje' displayed an opposite regulation. Levels of calystegine alkaloids were not significantly altered by treatments, implicating independent metabolic regulation of SGA and calystegine levels also under conditions of high SGA accumulation. Metabolomic and transcriptomic analyses identified a small number of key genes whose expression correlated with SGA differences between cultivars. Overexpression of two key genes in transgenic low-SGA potato cultivars increased their leaf SGA levels significantly. Discussion The results show that a strong response to light can underlie the SGA peaks that occasionally occur in certain potato cultivars and indicate that a between-cultivar variation in the expression of single SGA key genes can account for cultivar SGA differerences. We propose that current attempts to mitigate the SGA hazard will benefit from an increased consideration of cultivar-dependent SGA responses to post-harvest conditions, particularly light exposure. The identified key SGA genes can now be used as a molecular tool in this work.
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Affiliation(s)
- Irene Merino
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, Uppsala, Sweden
| | - Alexandra Olarte Guasca
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, Uppsala, Sweden
| | - Ales Krmela
- Department of Food Analysis and Nutrition, University of Chemistry and Technology Prague, Prague, Czechia
| | - Usman Arif
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, Uppsala, Sweden
| | - Ashfaq Ali
- National Bioinformatics Infrastructure Sweden (NBIS), SciLifeLab at Department of Immunotechnology, Lund University, Lund, Sweden
| | - Erik Westerberg
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, Uppsala, Sweden
| | - Siddhi Kashinanth Jalmi
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, Uppsala, Sweden
| | - Jana Hajslova
- Department of Food Analysis and Nutrition, University of Chemistry and Technology Prague, Prague, Czechia
| | - Vera Schulzova
- Department of Food Analysis and Nutrition, University of Chemistry and Technology Prague, Prague, Czechia
| | - Folke Sitbon
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, and Linnean Centre for Plant Biology, Uppsala, Sweden
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Solanum dulcamara L. Berries: A Convenient Model System to Study Redox Processes in Relation to Fruit Ripening. Antioxidants (Basel) 2023; 12:antiox12020346. [PMID: 36829905 PMCID: PMC9952312 DOI: 10.3390/antiox12020346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
The present study provides, for the first time, a physicochemical and biochemical characterization of the redox processes associated with the ripening of Solanum dulcamara L. (bittersweet) berries. Electron Paramagnetic Resonance Spectroscopy (EPRS) and Imaging (EPRI) measurements of reactive oxygen species (ROS) were performed in parallel with the tissue-specific metabolic profiling of major antioxidants and assessment of antioxidant enzymes activity. Fruit transition from the mature green (MG) to ripe red (RR) stage involved changes in the qualitative and quantitative content of antioxidants and the associated cellular oxidation and peroxidation processes. The skin of bittersweet berries, which was the major source of antioxidants, exhibited the highest antioxidant potential against DPPH radicals and nitroxyl spin probe 3CP. The efficient enzymatic antioxidant system played a critical protective role against the deleterious effects of progressive oxidative stress during ripening. Here, we present the EPRI methodology to assess the redox status of fruits and to discriminate between the redox states of different tissues. Interestingly, the intracellular reoxidation of cell-permeable nitroxide probe 3CP was observed for the first time in fruits or any other plant tissue, and its intensity is herein proposed as a reliable indicator of oxidative stress during ripening. The described noninvasive EPRI technique has the potential to have broader application in the study of redox processes associated with the development, senescence, and postharvest storage of fruits, as well as other circumstances in which oxidative stress is implicated.
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Vos PG, Paulo MJ, Bourke PM, Maliepaard CA, van Eeuwijk FA, Visser RGF, van Eck HJ. GWAS in tetraploid potato: identification and validation of SNP markers associated with glycoalkaloid content. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2022; 42:76. [PMID: 37313326 PMCID: PMC10248624 DOI: 10.1007/s11032-022-01344-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 11/18/2022] [Indexed: 06/15/2023]
Abstract
Genome-wide association studies (GWAS) are a useful tool to unravel the genetic architecture of complex traits, but the results can be difficult to interpret. Population structure, genetic heterogeneity, and rare alleles easily result in false positive or false negative associations. This paper describes the analysis of a GWAS panel combined with three bi-parental mapping populations to validate GWAS results, using phenotypic data for steroidal glycoalkaloid (SGA) accumulation and the ratio (SGR) between the two major glycoalkaloids α-solanine and α-chaconine in potato tubers. SGAs are secondary metabolites in the Solanaceae family, functional as a defence against various pests and pathogens and in high quantities toxic for humans. With GWAS, we identified five quantitative trait loci (QTL) of which Sga1.1, Sgr8.1, and Sga11.1 were validated, but not Sga3.1 and Sgr7.1. In the bi-parental populations, Sga5.1 and Sga7.1 were mapped, but these were not identified with GWAS. The QTLs Sga1.1, Sga7.1, Sgr7.1, and Sgr8.1 co-localize with genes GAME9, GAME 6/GAME 11, SGT1, and SGT2, respectively. For other genes involved in SGA synthesis, no QTLs were identified. The results of this study illustrate a number of pitfalls in GWAS of which population structure seems the most important. We also show that introgression breeding for disease resistance has introduced new haplotypes to the gene pool involved in higher SGA levels in certain pedigrees. Finally, we show that high SGA levels remain unpredictable in potato but that α-solanine/α-chaconine ratio has a predictable outcome with specific SGT1 and SGT2 haplotypes. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-022-01344-2.
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Affiliation(s)
- Peter G. Vos
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
- Present Address: Centre for BioSystems Genomics, P.O. Box 98, 6700 AB Wageningen, The Netherlands
- Current Address: HZPC, Edisonweg 5, 8501 XG Joure, The Netherlands
- Graduate School Experimental Plant Sciences, Wageningen University & Research, Wageningen, Netherlands
| | - M. João Paulo
- Present Address: Centre for BioSystems Genomics, P.O. Box 98, 6700 AB Wageningen, The Netherlands
- Biometris, Wageningen University and Research, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Peter M. Bourke
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
| | - Chris A. Maliepaard
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
| | - Fred A. van Eeuwijk
- Biometris, Wageningen University and Research, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Richard G. F. Visser
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
- Present Address: Centre for BioSystems Genomics, P.O. Box 98, 6700 AB Wageningen, The Netherlands
| | - Herman J. van Eck
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
- Present Address: Centre for BioSystems Genomics, P.O. Box 98, 6700 AB Wageningen, The Netherlands
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Zhao DK, Zhao Y, Chen SY, Kennelly EJ. Solanum steroidal glycoalkaloids: structural diversity, biological activities, and biosynthesis. Nat Prod Rep 2021; 38:1423-1444. [DOI: 10.1039/d1np00001b] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chemical structures of typical Solanum steroidal glycoalkaloids from eggplant, tomato, and potato.
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Affiliation(s)
- Da-Ke Zhao
- Biocontrol Engineering Research Center of Plant Disease and Pest, Biocontrol Engineering Research Center of Crop Disease and Pest, School of Ecology and Environment, Yunnan University, Kunming, 650504, P. R. China
| | - Yi Zhao
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, New York, 10468, USA
- PhD Program in Biology, The Graduate Center, City University of New York, New York, 10016, USA
| | - Sui-Yun Chen
- Biocontrol Engineering Research Center of Plant Disease and Pest, Biocontrol Engineering Research Center of Crop Disease and Pest, School of Ecology and Environment, Yunnan University, Kunming, 650504, P. R. China
| | - Edward J. Kennelly
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, New York, 10468, USA
- PhD Program in Biology, The Graduate Center, City University of New York, New York, 10016, USA
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