Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, Morelia, Michoacán C.P. 58030, Mexico.
Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, Morelia, Michoacán C.P. 58030, Mexico.
Plant Sci. 2024 May;342:112028. doi: 10.1016/j.plantsci.2024.112028. Epub 2024 Feb 14.
Iron (Fe) and phosphate (Pi) are two essential nutrients that are poorly available in the soil and should be supplemented either as fertilizers or organic amendments to sustain crop production. Currently, determining how rhizosphere bacteria contribute to plant mineral nutrient acquisition is an area of growing interest regarding its potential application in agriculture. The aim of this study was to investigate the influence of root colonization by Pseudomonas putida for Arabidopsis growth through Fe and Pi nutritional signaling. We found that root colonization by the bacterium inhibits primary root elongation and promotes the formation of lateral roots. These effects could be related to higher expression of two Pi starvation-induced genes and AtPT1, the major Pi transporter in root tips. In addition, P. putida influenced the accumulation of Fe in the root and the expression of different elements of the Fe uptake pathway. The loss of function of the protein ligase BRUTUS (BTS), and the bHLH transcription factors POPEYE (PYE) and IAA-LEUCINE RESISTANT3 (ILR3) compromised the root branching stimulation triggered by bacterial inoculation while the leaf chlorosis in the fit1 and irt1-1 mutant plants grown under standard conditions could be bypassed by P. putida inoculation. The WT and both mutant lines showed similar Fe accumulation in roots. P. putida repressed the expression of the IRON-REGULATED TRANSPORTER 1 (IRT1) gene suggesting that the bacterium promotes an alternative Fe uptake mechanism. These results open the door for the use of P. putida to enhance nutrient uptake and optimize fertilizer usage by plants.
铁（Fe）和磷酸盐（Pi）是两种在土壤中含量较低的必需营养物质，应作为肥料或有机改良剂进行补充，以维持作物的生产。目前，确定根际细菌如何促进植物矿质养分的获取是一个日益受到关注的领域，因为它在农业中的应用具有潜力。本研究的目的是研究根际细菌 Pseudomonas putida 通过 Fe 和 Pi 营养信号对拟南芥生长的影响。我们发现，细菌对根的定殖抑制了主根的伸长，并促进了侧根的形成。这些影响可能与两个 Pi 饥饿诱导基因和根尖主要 Pi 转运体 AtPT1 的更高表达有关。此外，P. putida 影响了根中 Fe 的积累和 Fe 吸收途径不同元素的表达。蛋白连接酶 BRUTUS（BTS）的功能丧失，以及 bHLH 转录因子 POPEYE（PYE）和 IAA-LEUCINE RESISTANT3（ILR3）的功能丧失，削弱了细菌接种触发的根分枝刺激，而在标准条件下生长的 fit1 和 irt1-1 突变体植物的叶片黄化可以通过 P. putida 接种来绕过。WT 和两种突变体在根中都表现出相似的 Fe 积累。P. putida 抑制了 IRON-REGULATED TRANSPORTER 1（IRT1）基因的表达，这表明该细菌促进了一种替代的 Fe 吸收机制。这些结果为利用 P. putida 来增强植物的养分吸收和优化肥料使用开辟了道路。
