Impact of the TaMATE1B gene on above and below-ground growth of durum wheat grown on an acid and Al3+-toxic soil

Background and aims Subsoil acidity with a high aluminium (Al3+) soil content inhibits root growth and proliferation of durum wheat (tetraploid AABB, Triticum turgidum) leading to poor nutrient and water uptake. This study evaluated the impact of Al3+-tolerantTaMATE1B allele on root and shoot traits of durum wheat grown in an acidic soil with a high Al(3+)concentration. Methods Two durum wheat lines, Jandaroi-TaMATE1B with the TaMATE1B gene introgressed from Al3+-tolerant bread wheat and Jandaroi-null (a sister line lacking the Al3+-tolerant TaMATE1B allele), were grown in rhizoboxes in a glasshouse. We mapped root growth and proliferation over time and measured shoot traits and grain yield. Results Introgression of the Al3+-tolerant TaMATE1B allele into durum wheat enabled root growth and proliferation below 0.25 m of the soil profile, where the soil pH was low (4.1, CaCl2 extract) with high Al3+ content (16.5 mg kg(-1)), and increased total root length and biomass at 42 days after sowing (DAS; Z(33)) by 38.3 and 22%, respectively, relative to the Jandaroi-null. Differences in root growth between the two lines were apparent from tillering stage (Z(33)) and by 50% anthesis (Z(64)), respectively. Jandaroi-TaMATE1B had 69.2% greater root biomass, 76.2% greater root length, 5.89% greater leaf area and 18% greater shoot biomass than Jandaroi-null at 50% anthesis (Z(64)). Time to anthesis and physiological maturity was delayed 6-7 days in Jandaroi-TaMATE1B, compared to Jandaroi-null. Jandaroi-TaMATE1B tended to have relatively greater, but not significantly different, shoot biomass, grain yield and yield components than Jandaroi-null. Conclusions Introgression of the Al3+-tolerant TaMATE1B allele into durum wheat enabled root growth and proliferation down an acidic soil profile with a high Al3+ concentration. We assume that in the field where plants need to acquire water at depth differences in above-ground parameters would be amplified.