AUTHOR=Kong Wei-Liang , Wang Ya-Hui , Wu Xiao-Qin 

TITLE=Enhanced Iron Uptake in Plants by Volatile Emissions of Rahnella aquatilis JZ-GX1

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.704000

DOI=10.3389/fpls.2021.704000

ISSN=1664-462X

ABSTRACT=<p>Iron deficiency in soil has crucially restricted agricultural and forestry production. Volatile organic compounds (VOCs) produced by beneficial microorganisms have been proven to play an important role in inducing abiotic stress tolerance in plants. We investigated the effects of VOCs released by the rhizobacterium <italic>Rahnella aquatilis</italic> JZ-GX1 on the growth and root parameters of <italic>Arabidopsis thaliana</italic> under iron deficiency. The effect of the rhizobacterial VOCs on the gene expression in iron uptake and hormone signaling pathways were detected by RT-qPCR. Finally, the VOCs of the JZ-GX1 strain that could promote plant growth under iron deficiency stress were screened. The results showed that the JZ-GX1 strain could induce <italic>A. thaliana</italic> tolerance to iron deficiency stress by promoting the development of lateral roots and root hairs and increasing the activities of H<sup>+</sup> ATPase and Fe<sup>3+</sup> reductase. In addition, the <italic>AHA2</italic>, <italic>FRO2</italic>, and <italic>IRT1</italic> genes of <italic>A. thaliana</italic> exposed to JZ-GX1-emitted VOCs were upregulated 25-, 1. 81-, and 1.35-fold, respectively, and expression of the abscisic acid (ABA) synthesis gene <italic>NCED3</italic> was upregulated on both the 3rd and 5th days. Organic compounds were analyzed in the headspace of JZ-GX1 cultures, 2-undecanone and 3-methyl-1-butanol were found to promote <italic>Medicago sativa</italic> and <italic>A. thaliana</italic> growth under iron-limited conditions. These results demonstrated that the VOCs of <italic>R. aquatilis</italic> JZ-GX1 have good potential in promoting iron absorption in plants.</p>