Bruschini Alessandro, Coppa Eleonora, Quagliata Giulia, Marín-Sanz Miriam, Ferrucci Andrea, Spada Matteo, Sestili Francesco, Barro Francisco, Vigani Gianpiero, Astolfi Stefania
Department of Agricultural and Forestry Sciences (DAFNE), University of Tuscia, Viterbo, Italy.
Department of Plant Breeding, Institute for Sustainable Agriculture (IAS), Spanish National Research Council (CSIC), Córdoba, Spain.
Physiol Plant. 2025 Sep-Oct;177(5):e70524. doi: 10.1111/ppl.70524.
Fe deficiency is a major global challenge for agriculture. While high sulfur (S) supply can improve Fe nutrition in some grasses, the underlying mechanisms are poorly understood. This study investigated four genetically distinct durum wheat genotypes (Svevo, Karim, LcyE AB, and Svems16) to test the hypothesis that they employ different S-mediated strategies to maintain Fe homeostasis under varying Fe availability. Fe deficiency inhibited plant growth and induced chlorosis with genotypic differences in severity. Notably, high S mitigated chlorosis in Karim and promoted root development in most genotypes, especially Svems16. Ionomic analysis showed that Fe deficiency primarily drove nutrient shifts in roots, but adding S restored shoot ionomic profiles. Total S analysis revealed genotype-specific accumulation. Svevo showed consistently low S, possibly due to a sulfate transporter variant. Conversely, Karim exhibited elevated root S under combined stress, suggesting increased S channeling to phytosiderophore (PS) biosynthesis, supported by genotype-dependent PS release. Genotyping-by-sequencing identified variants in methionine metabolism and PS-related genes, offering molecular bases for the observed physiological differences. ATPS and OASTL activity patterns further confirmed the genotype-specific role of root S metabolism in Fe deficiency response. Grain ionomics revealed that LcyE AB enhanced Fe accumulation under combined high S and Fe deficiency, Svems16 under high S, while Karim, the most sensitive, had reduced grain Fe under deficiency. Our results highlight distinct, genotype-specific strategies for maintaining Fe homeostasis and identify promising targets for breeding programs aimed at improving nutrient use efficiency and biofortification in durum wheat.
缺铁是全球农业面临的重大挑战。虽然高硫（S）供应可以改善某些禾本科植物的铁营养，但其潜在机制尚不清楚。本研究调查了四种遗传上不同的硬粒小麦基因型（斯韦沃、卡里姆、LcyE AB和Svems16），以检验它们在不同铁有效性下采用不同的硫介导策略来维持铁稳态的假设。缺铁抑制了植物生长并导致黄化，且黄化严重程度存在基因型差异。值得注意的是，高硫减轻了卡里姆的黄化，并促进了大多数基因型的根系发育，尤其是Svems16。离子组学分析表明，缺铁主要导致根系养分转移，但添加硫可恢复地上部离子组学特征。总硫分析揭示了基因型特异性积累。斯韦沃的硫含量一直较低，可能是由于硫酸盐转运体变体所致。相反，卡里姆在复合胁迫下根系硫含量升高，这表明硫向植物铁载体（PS）生物合成的通道增加，这得到了基因型依赖性PS释放的支持。全基因组测序鉴定了甲硫氨酸代谢和PS相关基因的变体，为观察到的生理差异提供了分子基础。ATP硫酸化酶和O-乙酰丝氨酸（硫醇）裂解酶活性模式进一步证实了根系硫代谢在缺铁反应中的基因型特异性作用。籽粒离子组学显示，LcyE AB在高硫和缺铁复合条件下增强了铁积累，Svems16在高硫条件下增强了铁积累，而最敏感的卡里姆在缺铁条件下籽粒铁含量降低。我们的研究结果突出了维持铁稳态的不同基因型特异性策略，并为旨在提高硬粒小麦养分利用效率和生物强化的育种计划确定了有前景的目标。
