AUTHOR=Bilal Saqib , Khan Abdul L. , Shahzad Raheem , Asaf Sajjad , Kang Sang-Mo , Lee In-Jung 

TITLE=Endophytic Paecilomyces formosus LHL10 Augments Glycine max L. Adaptation to Ni-Contamination through Affecting Endogenous Phytohormones and Oxidative Stress

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00870

DOI=10.3389/fpls.2017.00870

ISSN=1664-462X

ABSTRACT=<p>This study investigated the Ni-removal efficiency of phytohormone-producing endophytic fungi <italic>Penicillium janthinellum</italic>, <italic>Paecilomyces formosus</italic>, <italic>Exophiala</italic> sp., and <italic>Preussia</italic> sp. Among four different endophytes, <italic>P. formosus</italic> LHL10 was able to tolerate up to 1 mM Ni in contaminated media as compared to copper and cadmium. <italic>P. formosus</italic> LHL10 was further assessed for its potential to enhance the phytoremediation of <italic>Glycine max</italic> (soybean) in response to dose-dependent increases in soil Ni (0.5, 1.0, and 5.0 mM). Inoculation with <italic>P. formosus</italic> LHL10 significantly increased plant biomass and growth attributes as compared to non-inoculated control plants with or without Ni contamination. LHL10 enhanced the translocation of Ni from the root to the shoot as compared to the control. In addition, <italic>P. formosus</italic> LHL10 modulated the physio-chemical apparatus of soybean plants during Ni-contamination by reducing lipid peroxidation and the accumulation of linolenic acid, glutathione, peroxidase, polyphenol oxidase, catalase, and superoxide dismutase. Stress-responsive phytohormones such as abscisic acid and jasmonic acid were significantly down-regulated in fungal-inoculated soybean plants under Ni stress. LHL10 Ni-remediation potential can be attributed to its phytohormonal synthesis related genetic makeup. RT-PCR analysis showed the expression of <italic>indole-3-acetamide hydrolase</italic>, <italic>aldehyde dehydrogenase</italic> for indole-acetic acid and <italic>geranylgeranyl-diphosphate synthase</italic>, <italic>ent-kaurene oxidase</italic> (<italic>P450-4</italic>), <italic>C13-oxidase</italic> (<italic>P450-3</italic>) for gibberellins synthesis. In conclusion, the inoculation of <italic>P. formosus</italic> can significantly improve plant growth in Ni-polluted soils, and assist in improving the phytoremediation abilities of economically important crops.</p>