Open Access

ARTICLE

Mycorrhiza improves cold tolerance of Satsuma orange by inducing antioxidant enzyme gene expression

MING-AO CAO¹, FEI ZHANG², ELSAYED FATHI ABD_ALLAH³, QIANGSHENG WU^1,*

1 College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, China
2 College of Biology and Agricultural Resources, Huanggang Normal University, Huanggang, 438000, China
3 Plant Production Department, College of Food and Agricultural Sciences, King Saud University, Riyadh, 11451, Saudi Arabia

* Corresponding Author: Qiangsheng Wu,

(This article belongs to the Special Issue: Mycorrhizal Fungal Roles in Stress Tolerance of Plants)

BIOCELL 2022, 46(8), 1959-1966. https://doi.org/10.32604/biocell.2022.020391

Received 21 November 2021; Accepted 06 January 2022; Issue published 22 April 2022

Abstract

A potted experiment was carried out to study the effect of an arbuscular mycorrhizal fungus (Diversispora versiformis) and arbuscular mycorrhizal like fungus (Piriformospora indica) on antioxidant enzyme defense system of Satsuma orange (Citrus sinensis cv. Oita 4) grafted on Poncirus trifoliata under favourable temperature (25°C) and cold temperature (0°C) for 12 h. Such short-term treatment of cold temperature did not cause any significant change in root fungal colonization and spore density in soil. Under cold stress, D. versiformis inoculation did not change the activity of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in leaves and roots, whereas P. indica inoculation significantly increased the activity of CAT in roots and POD in leaves only. In addition, inoculation of two mycorrhizal fungi under cold stress significantly increased the relative expression levels of PtPOD and PtF-SOD in leaves, P. indica up-regulated the expression levels of PtCu/Zn-SOD in leaves, and D. versiformis also induced the expression levels of PtMn-SOD and PtCAT1 in leaves. In addition, inoculated Oita 4 trees maintained significantly lower hydrogen peroxide levels and malondialdehyde contents in leaves and roots under cold temperature, suggesting lower oxidative damage. Therefore, we concluded that arbuscular mycorrhizal fungi (especially P. indica) mainly induced the expression of antioxidant enzyme genes, depending on the fungal species, and thus mitigated oxidative damage for higher cold resistance in inoculated plants.

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Keywords

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