AUTHOR=Han Li-Na , Wang Si-Jia , Chen Hui , Ren Ying , Xie Xian-An , Wang Xing-Yang , Hu Wen-Tao , Tang Ming 

TITLE=Arbuscular mycorrhiza mitigates zinc stress on Eucalyptus grandis through regulating metal tolerance protein gene expression and ionome uptake

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1022696

DOI=10.3389/fpls.2022.1022696

ISSN=1664-462X

ABSTRACT=<p>Arbuscular mycorrhizal (AM) fungi are symbionts of most terrestrial plants and enhance their adaptability in metal-contaminated soils. In this study, mycorrhized and non-mycorrhized <italic>Eucalyptus grandis</italic> were grown under different Zn treatments. After 6 weeks of treatment, the growing status and ionome content of plants as well as the expression patterns of metal tolerance proteins and auxin biosynthesis–related genes were measured. In this study, mycorrhized <italic>E</italic>. <italic>grandis</italic> showed higher biomass and height at a high level of Zn compared with non-mycorrhized plants. In addition, AM plants accumulated P, Mg, and Mn in roots and P, Fe, and Cu in shoots, which indicate that AM fungi facilitate the uptake of ionome nutrients to promote plant growth. In addition, mycorrhiza upregulated the expression of <italic>EgMTP1</italic> and <italic>EgMTP7</italic>, whose encoding proteins were predicted to be located at the vacuolar membrane. Meanwhile, Golgi membrane transporter <italic>EgMTP5</italic> was also induced in AM shoot. Our results suggest that AM likely mitigates Zn toxicity through sequestrating excess Zn into vacuolar and Golgi. Furthermore, the expression of auxin biosynthesis–related genes was facilitated by AM, and this is probably another approach for Zn tolerance.</p>