Nitrogen fixation and mucilage production on maize aerial roots is controlled by aerial root development and border cell functions

Autor: Vânia Carla Silva Pankievicz, Pierre-Marc Delaux, Valentina Infante, Hayley H. Hirsch, Shanmugam Rajasekar, Pablo Zamora, Dhileepkumar Jayaraman, Claudia Irene Calderon, Alan Bennett, Jean-Michel Ané
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Frontiers in Plant Science, Vol 13 (2022)
Druh dokumentu: article
ISSN: 1664-462X
DOI: 10.3389/fpls.2022.977056
Popis: Exploring natural diversity for biological nitrogen fixation in maize and its progenitors is a promising approach to reducing our dependence on synthetic fertilizer and enhancing the sustainability of our cropping systems. We have shown previously that maize accessions from the Sierra Mixe can support a nitrogen-fixing community in the mucilage produced by their abundant aerial roots and obtain a significant fraction of their nitrogen from the air through these associations. In this study, we demonstrate that mucilage production depends on root cap and border cells sensing water, as observed in underground roots. The diameter of aerial roots correlates with the volume of mucilage produced and the nitrogenase activity supported by each root. Young aerial roots produce more mucilage than older ones, probably due to their root cap’s integrity and their ability to produce border cells. Transcriptome analysis on aerial roots at two different growth stages before and after mucilage production confirmed the expression of genes involved in polysaccharide synthesis and degradation. Genes related to nitrogen uptake and assimilation were up-regulated upon water exposure. Altogether, our findings suggest that in addition to the number of nodes with aerial roots reported previously, the diameter of aerial roots and abundance of border cells, polysaccharide synthesis and degradation, and nitrogen uptake are critical factors to ensure efficient nitrogen fixation in maize aerial roots.
Databáze: Directory of Open Access Journals