Effects of Mycorrhizal Colonization on Transcriptional Expression of the Responsive Factor JERF3 and Stress-Responsive Genes in Banana Plantlets in Response to Combined Biotic and Abiotic Stresses

Abstract

Banana plants (Musa acuminata L.) are exposed to various biotic and abiotic stresses that affect their production worldwide. Banana plants respond to these stresses, but their responses to combined stresses are unique and differ from those to various individual stresses. This study reported the effects of the mycorrhizal colonization of banana roots and/or infection with root rot on the transcriptional expression of the responsive factor JERF3 and stress-responsive genes (POD, PR1, CHI, and GLU) under different salinity levels. Different transcriptional levels were recorded in response to the individual, dual, or triple treatments. All the applied biotic and abiotic stresses triggered the transcriptional expression of the tested genes when individually applied, but they showed different influences varying from synergistic to antagonistic when applied in combinations. The salinity stress had the strongest effect when applied in combination with the biotic stress and/or mycorrhizal colonization, especially at high concentrations. Moreover, the salinity level differentially affects the banana responses under combined stresses and/or mycorrhizal colonization in addition, the mycorrhizal colonization of banana plantlets improved their growth, photosynthesis, and nutrient uptake, as well as greatly alleviated the detrimental effects of salt and infection stresses. In general, the obtained results indicated that the responses of banana plantlets under the combined stresses are more complicated and differed from those under the individual stresses depending on the crosstalks between the signaling pathways.

Ascophyllum nodosum Extract and Mycorrhizal Colonization Synergistically Trigger Immune Responses in Pea Plants against Rhizoctonia Root Rot, and Enhance Plant Growth and Productivity

“…The obtained results showed the upregulating effect of this treatment on the studied defense-related genes. Jasmonate and ethylene-responsive factor 3 ( JERF3 ) is a transcription factor which controls the expression of a group of defense-related genes via both jasmonate and ethylene pathways in the plant, in response to different stresses [ 14 ]. The triggered expression of JERF3 , which was reported in this study, may discuss the resistance-inducing effect against Rhizoctonia root rot in pea.…”

“…In addition, it upregulated the expression of different defense-related genes. An analysis of the A. nodosum extract showed that it contains abscisic acid and ethylene, which are multifunctional phytohormones, and are involved in various processes including growth, development, and responses against different biotic and abiotic stresses [ 14 ]. Both hormones are known as key signaling molecules, which regulate many stress-responsive genes via abscisic acid and ethylene-signaling pathways, inducing the plant resistance via variable mechanisms [ 45 , 46 ].…”

“…Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs (subphylum Glomeromycotina) that live in a mutualistic relationship with roots of the majority of terrestrial plants [ 12 ]. Multiple benefits are received by the plant partner due to association with AMF, such as improving the plant growth [ 13 ], enhancing nutrients uptake, inducing plant tolerance to salinity and drought stresses [ 14 ], and triggering plant resistance against different plant diseases [ 15 ]. The application of AMF as a biocontrol agent against different plant diseases including Rhizoctonia root rot has been widely studied by many researchers all over the world [ 16 , 17 , 18 , 19 ].…”

“…Plants tend to activate multiple defense responses in order to defend themselves against pathogen attack. One of the main defense responses is triggering various signaling pathways such as salicylic acid, jasmonic acid, and ethylene pathways that regulate many defense-related genes in the plant [ 14 ]. Crosstalks between these signaling pathways may form the net plant resistance to the pathogen.…”

Exogenous Application of Melatonin and Methyl Jasmonate as a Pre-Harvest Treatment Enhances Growth of Barhi Date Palm Trees, Prolongs Storability, and Maintains Quality of Their Fruits under Storage Conditions

“…Methyl jasmonate (Mj), the methyl ester of jasmonic acid, is an important phytohormone, which has many physiological and developmental roles in plants, including growth promotion, signaling, fertility, stress tolerance, senescence, seed germination, formation of storage organs, fruit ripening, stimulation of antioxidant activities, nectar biosynthesis, and regulation of various defense-related genes [ 10 , 11 , 12 ]. Fan et al [ 13 ] reported that exogenous application of MJ at 5 mM inhibited ethylene accumulation, significantly delayed postharvest ripening and senescence in eggplant fruits, maintained their quality, and prolonged their postharvest life during storage.…”