Nasr Esfahani Maryam, Koch Lisa, Hofmann Jörg, Sonnewald Sophia, Sonnewald Uwe
Department of Biology, Chair of Biochemistry, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
Plant J. 2025 Sep;123(5):e70445. doi: 10.1111/tpj.70445.
While plants adapt to fluctuating phosphorus (P) availability in soils by enhancing phosphate acquisition or optimizing internal P-utilization, the spatiotemporal dynamics of these responses, particularly in crops, remain poorly understood. This study systematically investigated how and when potato organs respond to fluctuating P availability across different developmental stages using transcriptomic, metabolomic, and physiological analyses of leaves, roots, and tubers. Transcriptomic data revealed dynamic, organ- and stage-specific responses to P-deficiency, with the highest number of differentially expressed genes in leaves before tuberization and in roots during tuberization. P-deficiency led to a marked accumulation of proline in tubers and nitrogen-rich amino acids, particularly glutamine and asparagine, in roots and leaves. Carbohydrate metabolism exhibited severity- and time-dependent changes: severe P-deficiency triggered earlier, stronger, but transient carbohydrate accumulation, whereas medium P-deficiency led to a gradual and sustained increase in leaves and roots. Hexose phosphates and organic acids accumulated in roots under P-stress, especially severe P-stress, during early vegetative growth, followed by a marked reduction during tuberization. During tuber filling, severe P-deficiency reduced sucrose and starch in roots, decreased leaf starch but increased leaf sucrose, likely due to impaired translocation, and a decrease in tuber sucrose alongside increased starch due to reduced degradation. Under medium P-deficiency, sucrose and starch remained stable in leaves and tubers but declined in roots, reflecting a moderate shift in carbon allocation that maintained tuber development at the expense of root metabolism. These findings highlight the spatiotemporal regulation of metabolic and molecular responses to P-deficiency in potato and provide insights for improving nutrient use efficiency and stress resilience in crops.
虽然植物通过增强磷的吸收或优化内部磷的利用来适应土壤中磷有效性的波动，但这些反应的时空动态，尤其是在作物中，仍知之甚少。本研究通过对叶片、根系和块茎进行转录组学、代谢组学和生理学分析，系统地研究了马铃薯器官在不同发育阶段如何以及何时对磷有效性的波动做出反应。转录组数据揭示了对缺磷的动态、器官和阶段特异性反应，在块茎形成前叶片中以及块茎形成期间根系中差异表达基因的数量最多。缺磷导致块茎中脯氨酸显著积累，以及根系和叶片中富含氮的氨基酸，特别是谷氨酰胺和天冬酰胺的积累。碳水化合物代谢表现出严重程度和时间依赖性变化：严重缺磷引发更早、更强但短暂的碳水化合物积累，而中度缺磷导致叶片和根系中碳水化合物逐渐持续增加。在营养生长早期，磷胁迫下，尤其是严重磷胁迫下，根系中磷酸己糖和有机酸积累，随后在块茎形成期间显著减少。在块茎充实期，严重缺磷减少了根系中的蔗糖和淀粉，降低了叶片淀粉但增加了叶片蔗糖，这可能是由于转运受损，并且块茎蔗糖减少同时淀粉增加是由于降解减少。在中度缺磷条件下，蔗糖和淀粉在叶片和块茎中保持稳定，但在根系中下降，反映了碳分配的适度转变，即以牺牲根系代谢为代价维持块茎发育。这些发现突出了马铃薯对缺磷的代谢和分子反应的时空调控，并为提高作物养分利用效率和抗逆性提供了见解。
