State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100839, China.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210008, China.
Plant Sci. 2023 Apr;329:111605. doi: 10.1016/j.plantsci.2023.111605. Epub 2023 Jan 24.
The physiological and molecular mechanisms between phosphorus (P) and iron (Fe) interactions are still elusive although they have been extensively investigated. In this study, we uncovered that limiting P supply could alleviate Fe deficiency in Arabidopsis (Col-0). Under Fe deficiency, P deficiency (-Fe-P) decreased cell wall Fe accumulation in root, but elevated Fe accumulation in the shoot, implying that the reduced Fe retention in the root cell wall may contribute to the P-deficiency-alleviated Fe deficiency in the shoot. On the other hand, increasing P supply could mimic the degree of Fe deficiency in terms of the expressions of genes induced after Fe deficient treatment. The components of the root cell wall showed that there was no distinction in the pectin content and the Fe retention in pectin between -Fe and -Fe-P treatments, while hemicellulose 1 content and Fe retained in it were decreased significantly in -Fe-P treatment as compared with -Fe treatment. The time-course experiment showed that decreasing cell wall retained Fe was mainly from the corresponding decrease in hemicellulose 1 retained Fe. Furthermore, the up-regulation of IRT1 expression in -Fe-P was obviously lower than -Fe. All these suggest that the P deficiency-induced decrease of hemicellulose 1 component leads to reutilization of root cell wall Fe and improvement of Fe nutrition in shoot in Fe deficient Arabidopsis. Our results provide a novel explanation of the interplay between Fe and P in Arabidopsis.
尽管已经进行了广泛的研究，但磷 (P) 和铁 (Fe) 相互作用的生理和分子机制仍然难以捉摸。在这项研究中，我们发现限制磷供应可以缓解拟南芥（Col-0）的铁缺乏。在缺铁条件下，缺磷（-Fe-P）减少了根细胞壁中铁的积累，但增加了地上部的铁积累，这表明根细胞壁中铁的保留减少可能有助于减少地上部铁的保留。另一方面，增加磷供应可以模拟缺铁处理后基因表达诱导的缺铁程度。根细胞壁的组成表明，在果胶含量和果胶中铁的保留方面，-Fe 和 -Fe-P 处理之间没有区别，而 -Fe-P 处理中半纤维素 1 含量和其中保留的铁与 -Fe 处理相比显著降低。时程实验表明，减少细胞壁中保留的铁主要是由于半纤维素 1 保留的铁相应减少。此外，-Fe-P 中 IRT1 表达的上调明显低于 -Fe。所有这些都表明，缺磷诱导的半纤维素 1 成分减少导致缺铁拟南芥中根细胞壁铁的再利用和地上部铁营养的改善。我们的结果为拟南芥中铁和磷之间的相互作用提供了一个新的解释。
