Department of Mycorrhizal Symbioses, Institute of Botany of the Czech Academy of Sciences, Průhonice, Czech Republic.
Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, FCEFyN, Universidad Nacional de Córdoba, Córdoba, Argentina.
Plant Cell Environ. 2022 Feb;45(2):512-527. doi: 10.1111/pce.14212. Epub 2021 Dec 3.
Nitrogen (N) and phosphorus (P) are among the most important macronutrients for plant growth and development, and the most widely used as fertilizers. Understanding how plants sense and respond to N and P deficiency is essential to optimize and reduce the use of chemical fertilizers. Strigolactones (SLs) are phytohormones acting as modulators and sensors of plant responses to P deficiency. In the present work, we assess the potential role of SLs in N starvation and in the N-P signalling interplay. Physiological, transcriptional and metabolic responses were analysed in wild-type and SL-deficient tomato plants grown under different P and N regimes, and in plants treated with a short-term pulse of the synthetic SL analogue 2'-epi-GR24. The results evidence that plants prioritize N over P status by affecting SL biosynthesis. We also show that SLs modulate the expression of key regulatory genes of phosphate and nitrate signalling pathways, including the N-P integrators PHO2 and NIGT1/HHO. The results support a key role for SLs as sensors during early plant responses to both N and phosphate starvation and mediating the N-P signalling interplay, indicating that SLs are involved in more physiological processes than so far proposed.
氮（N）和磷（P）是植物生长和发育最重要的大量营养素之一，也是最广泛用作肥料的元素。了解植物如何感知和响应 N 和 P 缺乏对于优化和减少化肥的使用至关重要。独脚金内酯（SLs）是植物激素，作为 P 缺乏响应的调节剂和传感器。在本工作中，我们评估了 SLs 在 N 饥饿和 N-P 信号相互作用中的潜在作用。在不同的 P 和 N 条件下生长的野生型和 SL 缺陷型番茄植物以及用合成 SL 类似物 2'-epi-GR24 进行短期脉冲处理的植物中，分析了生理、转录和代谢响应。结果表明，植物通过影响 SL 生物合成来优先考虑 N 而不是 P 状态。我们还表明，SLs 调节磷酸盐和硝酸盐信号通路的关键调节基因的表达，包括 N-P 整合因子 PHO2 和 NIGT1/HHO。结果支持 SLs 在植物对 N 和磷酸盐饥饿的早期响应中作为传感器的关键作用，并介导 N-P 信号相互作用，表明 SLs 参与的生理过程比目前提出的更多。
