Identification, transcriptional and functional analysis of heat‐shock protein 90s in banana (Musa acuminata L.) highlight their novel role in melatonin‐mediated plant response to Fusarium wilt

Abstract

As one popular fresh fruit, banana (Musa acuminata) is cultivated in the world's subtropical and tropical areas. In recent years, pathogen Fusarium oxysporum f. sp. cubense (Foc) has been widely and rapidly spread to banana cultivated areas, causing substantial yield loss. However, the molecular mechanism of banana response to Foc remains unclear, and functional identification of disease-related genes is also very limited. In this study, nine 90 kDa heat-shock proteins (HSP90s) were genomewide identified. Moreover, the expression profile of them in different organs, developmental stages, and in response to abiotic and fungal pathogen Foc were systematically analyzed. Notably, we found that the transcripts of 9 MaHSP90s were commonly regulated by melatonin (N-acetyl-5-methoxytryptamine) and Foc infection. Further studies showed that exogenous application of melatonin improved banana resistance to Fusarium wilt, but the effect was lost when cotreated with HSP90 inhibitor (geldanamycin, GDA). Moreover, melatonin and GDA had opposite effect on auxin level in response to Foc4, while melatonin and GDA cotreated plants had no significant effect, suggesting the involvement of MaHSP90s in the cross talk of melatonin and auxin in response to fungal infection. Taken together, this study demonstrated that MaHSP90s are essential for melatonin-mediated plant response to Fusarium wilt, which extends our understanding the putative roles of MaHSP90s as well as melatonin in the biological control of banana Fusarium wilt.

RAV transcription factors are essential for disease resistance against cassava bacterial blight via activation of melatonin biosynthesis genes

“…Plant melatonin level was extracted from leave samples using extraction mixture (acetone:methanol:water (v:v:v) = 89:10:1). After centrifugation, the endogenous melatonin was quantified in the supernatant using melatonin enzyme‐linked immunosorbent assay (ELISA) kit (Jianglai Biotechnology, Shanghai, China) as Wei et al described …”

“…In recent years, accumulated evidence has confirmed that melatonin ( N ‐acetyl‐5‐methoxytryptamine) is involved in plant against various pathogen bacterials and fungers, including Diplocarpon mali , Fusarium oxysporum f. sp. cubense , and Pseudomonas syringe pv. tomato DC3000 .…”

Overexpression of rice serotonin N‐acetyltransferase 1 in transgenic rice plants confers resistance to cadmium and senescence and increases grain yield

“…Since the first discovery of melatonin in plants in 1995, many pharmacological studies have been performed to investigate its functional and physiological significance . Large numbers of experiments involving exogenous application of melatonin to a series of plant species indicated that melatonin acts as a biostimulator in plants by enhancing a myriad of defense responses against abiotic stresses, including oxidative stress, high temperature, cold, senescence, drought, and salt, as well as biotic stress such as pathogen attacks . In addition to the defense responses, melatonin has also been implicated in promoting plant growth processes, such as seedling growth, flowering, nutrient absorption, and fruit ripening, suggesting a potential role of melatonin as a plant growth factor .…”

Synergistic anti‐oomycete effect of melatonin with a biofungicide against oomycetic black shank disease

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