Transcriptional and physiological analyses of Fe deficiency response in maize reveal the presence of Strategy I components and Fe/P interactions

BMC Genomics

Research Article

Anita Zamboni¹  Zeno Varanini¹  Laura Zanin²  Nicola Tomasi²  Roberto Pinton²  Silvia Venuti² 

[1] Dipartimento di Biotecnologie, University of Verona, Ca’ Vignal 1- Strada Le Grazie 15, I-37134, Verona, Italy;Dipartimento di Scienze Agroalimentari, Ambientali e Animali, University of Udine, via delle Scienze 206, I-33100, Udine, Italy;

关键词: Zea mays;    Iron;    Fe-source;    Gene expression;    Mineral nutrition;    NRAMP;    Phosphate transporter;    Phosphorous uptake;    Root acquisition;    Strategy II;   

DOI  :  10.1186/s12864-016-3478-4

 received in 2016-08-10, accepted in 2016-12-29,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundUnder limited iron (Fe) availability maize, a Strategy II plant, improves Fe acquisition through the release of phytosiderophores (PS) into the rhizosphere and the subsequent uptake of Fe-PS complexes into root cells. Occurrence of Strategy-I-like components and interactions with phosphorous (P) nutrition has been hypothesized based on molecular and physiological studies in grasses.ResultsIn this report transcriptomic analysis (NimbleGen microarray) of Fe deficiency response revealed that maize roots modulated the expression levels of 724 genes (508 up- and 216 down-regulated, respectively). As expected, roots of Fe-deficient maize plants overexpressed genes involved in the synthesis and release of 2’-deoxymugineic acid (the main PS released by maize roots). A strong modulation of genes involved in regulatory aspects, Fe translocation, root morphological modification, primary metabolic pathways and hormonal metabolism was induced by the nutritional stress. Genes encoding transporters for Fe2+ (ZmNRAMP1) and P (ZmPHT1;7 and ZmPHO1) were also up-regulated under Fe deficiency.Fe-deficient maize plants accumulated higher amounts of P than the Fe-sufficient ones, both in roots and shoots. The supply of 1 μM 59Fe, as soluble (Fe-Citrate and Fe-PS) or sparingly soluble (Ferrihydrite) sources to deficient plants, caused a rapid down-regulation of genes coding for PS and Fe(III)-PS transport, as well as of ZmNRAMP1 and ZmPHT1;7.Levels of 32P absorption essentially followed the rates of 59Fe uptake in Fe-deficient plants during Fe resupply, suggesting that P accumulation might be regulated by Fe uptake in maize plants.ConclusionsThe transcriptional response to Fe-deficiency in maize roots confirmed the modulation of known genes involved in the Strategy II and revealed the presence of Strategy I components usually described in dicots. Moreover, data here presented provide evidence of a close relationship between two essential nutrients for plants, Fe and P, and highlight a key role played by Fe and P transporters to preserve the homeostasis of these two nutrients in maize plants.

【 授权许可】

CC BY   
© The Author(s). 2017