The 5-azacytidine-induced epimutagenesis of sugarcane (Saccharum spp. hybrids) for aluminium tolerance

• Published in: Biochimica et biophysica acta. General subjects Vol. 1867; no. 12; p. 130491
• Main Authors: Koetle, Motselisi Jane, Osborn, Christine, Snyman, Sandra Jane, Rutherford, Richard Stuart
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2023
• Subjects: Abiotic stress; Acidic soils; aluminum; callus; Chimera dissolution; cultivars; Demethylation; Epibreeding; epigenetics; leaf area; multidimensional scaling; Mutant line; plantlets; Saccharum; stress tolerance; sugarcane; variance; vegetative propagation; water content; Chimera dissolution; Demethylation; Epibreeding; Abiotic stress; Acidic soils; Mutant line
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2023.130491

A protocol for generating aluminium (Al) tolerant sugarcane using 5-azacytidine (5-azaC)-induced epimutagenesis was developed. Eight (8) plantlets per gram of cultivar N51 calli were generated from the 5-azaC (100 μM) and Al (1.5–50 mM) treatment (+Az + Al) when compared with 104 plantlets from non-mutagenised, no Al control treatment. Following in vitro selection on 60 mM Al, ex vitro stress over four rounds of chimera dissolution during vegetative propagation was applied. In the final stress round, 36% of the Mut 2 epilines survived with plants showing higher relative water content (61.2%) when compared with 47.3% from the stressed control (S N51). The Mut 2 line maintained a higher green leaf area (83.4%) and longer roots (32.4 cm) under stress than S N51 (61.4% and 26.3 cm, respectively). Overall, Mut 2 had a high stress tolerance index of 85.4%, compared with 79.0% from the S N51, nearing that of the non-stressed N51 control (NS N51, 100%) when data were analysed using PCA and clustering analyses of morpho-physiological traits. Analysis of molecular variance (AMOVA) revealed high epigenetic differentiation (ɸst = 0.67) and a variation of 66.6% observed among N51 genotypes. The principal coordinate analysis (PCoA) showed that Mut 2 was epigenetically distinct from S N51. These findings support previous studies that 5-azaC can be used for novel trait creation via epimutagenesis and highlights the necessity for chimera dissolution to achieve stable traits in epibreeding of sugarcane. •Mut 2, had a high Al stress tolerance index of 85.4% vs 79.0% observed in the stressed control.•Epiline Mut 2 had higher relative water content (61.2%), leaf area (83.4%), and root length (32.4 cm) than stressed control (47.3%, 61.4%, 26.3 cm respectively).•High epigenetic differentiation (66.6%) between Mut 2 and control lines was recorded, indicating 5-azaC-induced epigenetic changes and distinctness.•5-azaC enables novel trait creation and the study highlights the importance of chimera dissolution for stable traits in epibreeding.