Souza Beatriz C O Q, Andrade Eduarda S, Ribeiro Clara C, Santos Rayssa P S S, Costa Lucas C, Tsehaye Yemane, Silva Maria Lígia S, Araújo Wagner L, Marchiori Paulo E R, Nascimento Vitor L
Department of Biology-Institute of Natural Sciences, Universidade Federal de Lavras, 37200-900, Lavras, MG, Brazil.
Department of Botany-Institute of Biological Sciences, Universidade de Brasilía, 70910-900, Brasília, DF, Brazil.
Plant Physiol Biochem. 2025 Jul 3;228:110213. doi: 10.1016/j.plaphy.2025.110213.
Phosphorus (P) is a macronutrient required as a structural and functional component of biomolecules; P homeostasis interacts with phytohormone signaling pathways, such as ethylene, leading to responses in plant growth and development. Tomato plants (Solanum lycopersicum L.) have been used as a model for physiological and biochemical studies, and the ethylene-insensitive mutant Never ripe (Nr) is useful for understanding how ethylene interferes and coordinates biological processes, including responses to nutritional stresses with P. Here we aimed to evaluate how the Nr plants respond to P stresses (absence - no P - and excess - 2× P), to understand how the crosstalk between ethylene signaling and P homeostasis works. For this, tomato plants of the wild type (WT) and Nr genotypes were submitted to fertigation with an adapted Hoagland solution in growth room conditions, two factors in a factorial arrangement, distributed in six treatments, two (genotypes) x three (P levels): (i) WT in P absence; (ii) WT in control; (iii) WT in P excess; (iv) Nr in P absence; (v) Nr in control; and (vi) Nr in P excess. Plant growth and yield, photosynthetic, biochemical, and nutritional parameters were quantified. The highest values of the biometric parameters were found mostly in Nr in all treatments, and fruit production was affected, being higher in the mutant than in WT in the P absence. Some photosynthetic parameters, such as CO assimilation and stomatal conductance, were higher in P absence for both genotypes. Nr plants showed lower levels of carbohydrates, increased amino acids and proteins, and better both P accumulation and efficiency. Nr plants also demonstrated higher vigor when exposed to P stresses, as verified by their highest biometric attributes. Increased levels of nitrogen compounds in Nr, especially proline, indicate that these plants have an intrinsic ability to accumulate these substances, might using them to better osmoregulate and resist P stress. These results demonstrate that ethylene perception plays an essential role in the signaling of P stresses, with the insensitive plants presenting a mitigation of the stress effects.
磷（P）是一种大量营养素，作为生物分子的结构和功能成分；磷稳态与植物激素信号通路相互作用，如乙烯，从而导致植物生长发育的响应。番茄植株（Solanum lycopersicum L.）已被用作生理和生化研究的模型，乙烯不敏感突变体“永不成熟”（Nr）有助于理解乙烯如何干扰和协调生物过程，包括对磷营养胁迫的响应。在这里，我们旨在评估Nr植株对磷胁迫（缺磷 - 无磷 - 和高磷 - 2倍磷）的反应，以了解乙烯信号与磷稳态之间的相互作用机制。为此，在生长室条件下，将野生型（WT）和Nr基因型的番茄植株用改良的霍格兰溶液进行滴灌施肥，采用二因素析因设计，分为六种处理，两（基因型）×三（磷水平）：（i）缺磷的WT；（ii）对照的WT；（iii）高磷的WT；（iv）缺磷的Nr；（v）对照的Nr；（vi）高磷的Nr。对植株的生长和产量、光合、生化和营养参数进行了量化。在所有处理中，生物统计学参数的最高值大多出现在Nr植株中，果实产量受到影响，在缺磷条件下，突变体的果实产量高于WT。两种基因型在缺磷时，一些光合参数，如二氧化碳同化和气孔导度较高。Nr植株的碳水化合物水平较低，氨基酸和蛋白质增加，磷积累和效率均较好。Nr植株在受到磷胁迫时也表现出更高的活力，这通过其最高的生物统计学属性得到验证。Nr中氮化合物水平的增加，尤其是脯氨酸，表明这些植株具有积累这些物质的内在能力，可能利用它们更好地进行渗透调节并抵抗磷胁迫。这些结果表明，乙烯感知在磷胁迫信号传导中起着至关重要的作用，乙烯不敏感植株表现出胁迫效应的减轻。
