TY - JOUR T1 - Contribution of External and Internal Phosphorus Sources to Grain P Loading in Durum Wheat (Triticum durum L.) Grown Under Contrasting P Levels. AU - El Mazlouzi,Mohamed, AU - Morel,Christian, AU - Chesseron,Coralie, AU - Robert,Thierry, AU - Mollier,Alain, Y1 - 2020/06/18/ PY - 2020/03/20/received PY - 2020/05/28/accepted PY - 2020/7/7/entrez PY - 2020/7/7/pubmed PY - 2020/7/7/medline KW - 32P tracer KW - P remobilization KW - durum wheat KW - grain P concentrations KW - hydroponic conditions KW - phosphorus KW - post-anthesis P uptake SP - 870 EP - 870 JF - Frontiers in plant science JO - Front Plant Sci VL - 11 N2 - Phosphorus (P) in durum wheat grains after anthesis originates from either the external P source or the internal remobilization of P from different plant organs. The supply of P and its use by the plant are important factors that can affect the contribution of each source to grain P nutrition. Thus, this experiment aimed to quantify the origin of P in grains of durum wheat plants with different P nutritional status. Wheat plants were grown from juvenile stages to maturity in complete nutrient solutions with either high (0.125 mM) or low (0.025 mM) P concentrations in greenhouse conditions. Phosphorus in nutrient solutions was spiked by introducing 32P after anthesis to quantify the external P uptake and its partitioning within plant organs (spikelets, leaves, stems, roots, and post-anthesis tillers) and grains. Phosphorus use efficiency in durum wheat plants was also determined. The low and high P supply resulted in two highly different plant nutritional P status. Plants with low P status remobilized most of their stored P in all organs and allocated more than 72% of post-anthesis P uptake to grain P nutrition, whereas in the high P plants this was only 56%. Enhanced remobilization of P and the efficient allocation of newly acquired P to grains were crucial for durum wheat grain P nutrition grown under low P supply. The remobilization of P represented 81% of grain P in low P plants while it represented 65% for high P plants. Organs that contributed the most to P remobilization in low P plants were spikelets (43%) and leaves (35%). The post-anthesis tiller development was reduced in low P plants suggesting a preferential allocation of P to grains under this treatment. We concluded that P loading into grains in durum wheat is mainly derived from the remobilization of internal P sources stored before anthesis, even at high external P supply during grain filling. SN - 1664-462X UR - https://www.unboundmedicine.com/medline/citation/32625228/Contribution_of_External_and_Internal_Phosphorus_Sources_to_Grain_P_Loading_in_Durum_Wheat__Triticum_durum_L___Grown_Under_Contrasting_P_Levels_ DB - PRIME DP - Unbound Medicine ER -