The Endophytic Fungus Piriformospora indica Reprograms Banana to Cold Resistance

Abstract

Banana (Musa spp.), one of the most important fruits worldwide, is generally cold sensitive. In this study, by using the cold-sensitive banana variety Tianbaojiao (Musa acuminate) as the study material, we investigated the effects of Piriformospora indica on banana cold resistance. Seedlings with and without fungus colonization were subjected to 4 °C cold treatment. The changes in plant phenotypes, some physiological and biochemical parameters, chlorophyll fluorescence parameters, and the expression of eight cold-responsive genes in banana leaves before and after cold treatment were measured. Results demonstrated that P. indica colonization reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2) but increased the activities of superoxide dismutase (SOD) and catalase (CAT) and the contents of soluble sugar (SS) and proline. Noteworthily, the CAT activity and SS content in the leaves of P. indica-colonized banana were significant (p < 0.05). After 24 h cold treatment, the decline in maximum photochemistry efficiency of photosystem II (Fv/Fm), photochemical quenching coefficient (qP), efficient quantum yield [Y(II)], and photosynthetic electron transport rate (ETR) in the leaves of P. indica-colonized banana was found to be lower than in the non-inoculated controls (p < 0.05). Moreover, although the difference was not significant, P. indica colonization increased the photochemical conversion efficiency and electron transport rate and alleviated the damage to the photosynthetic reaction center of banana leaves under cold treatment to some extent. Additionally, the expression of the most cold-responsive genes in banana leaves was significantly induced by P. indica during cold stress (p < 0.05). It was concluded that P. indica confers banana with enhanced cold resistance by stimulating antioxidant capacity, SS accumulation, and the expression of cold-responsive genes in leaves. The results obtained from this study are helpful for understanding the P. indica-induced cold resistance in banana.

Influences of Serendipita indica and Dictyophorae echinovolvata on the Growth and Fusarium Wilt Disease Resistance of Banana

“…S. indica is an arbuscular mycorrhizal-like fungus that can colonize plant roots extensively and form a symbiotic relationship with its host. Accumulated evidence has shown that the colonization of S. indica could improve the nutrient absorption, promote plant growth and development, and enhance the resistance or tolerance of banana to abiotic and biotic stresses [5][6][7][8]. Bamboo fungus is a nutritious edible mushroom which not only has high medicinal value, but also has antioxidant and anti-microbial activities.…”

“…In addition to the growth promoting effect, S. indica can also enhance the resistance of banana to both abiotic and biotic stresses. For example, Li et al reported that colonization of S. indica improved the banana cold resistance by stimulating antioxidant capacity, improving SS accumulation, and by regulating the expression of cold-responsive genes in banana leaves [6]; Bodjrenou et al found that colonization of S. indica improved the thermal resistance of banana [7]; Cheng et al reported that the fungus could improve the resistance of banana to Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4) by regulating the antioxidant enzyme activities of banana root [8].…”

Environmental interference of plant−microbe interactions

“…Furthermore, beneficial microbes stimulate the formation of antioxidants in plants that efficiently neutralize ROS (Balestrini et al, 2018;Hamilton et al, 2012;Li et al, 2021;Noctor & Foyer, 1998). Antioxidants with major roles in plants include catalase, flavonoids, peroxidases, proline and superoxide dismutase (Noctor et al, 2018).…”

Effect of Piriformospora indica-Induced Systemic Resistance and Basal Immunity Against Rhizoctonia cerealis and Fusarium graminearum in Wheat

“…The P. indica is well-known to be able to establish beneficial interactions with many different hosts, including monocotyledons such as barley, wheat, rice, corn, and dicotyledons, such as Arabidopsis and tobacco ( Qiang et al, 2012 ). The P. indica serves as an excellent model for beneficial microbes since it: (1) is genetically transformable and culturable in axenic conditions ( Zuccaro et al, 2009 ); (2) promotes plant growth and yield ( Kundu et al, 2021 ); (3) enhances plant tolerance against abiotic stress ( Li et al, 2021a ); and (4) primes plants for disease resistance against biotrophic and necrotrophic fungi ( Stein et al, 2008 ), oomycetes ( Trzewik et al, 2020 ), and viruses ( Fakhro et al, 2010 ).…”