Silicon application enhances resistance to xanthomonas wilt disease in banana

Abstract

Silicon (Si) has been reported to be a beneficial element and shown to enhance disease resistance in many crops, although it is not regarded to be critical for plant growth and development. In this study, the potential effect of Si supplementation on resistance to banana xanthomonas wilt (BXW) disease was evaluated using various banana cultivars. Si application at a concentration of 200 mg per plant per week was found to be optimal in enhancing resistance to BXW without any detrimental effects on plant growth. The effect of varying the duration of Si application showed continuous supply of Si before and after pathogen inoculation led to a significantly higher level of resistance to BXW in all the banana cultivars tested in comparison to non-Si-treated inoculated plants. Banana plants treated with Si before pathogen inoculation only, also exhibited high protection against BXW similar to plants treated continuously with Si. The total Si content in leaves increased significantly in Si-treated plants in comparison to non-Si-treated control plants. The amount of Si accumulation was directly correlated to the duration of application; plants treated with Si continuously showed significantly higher amounts of Si accumulation in leaves than plants where Si application was terminated following bacterial inoculation or when Si application started immediately after pathogen inoculation. The Si-treated plants also showed higher activity of the peroxidase enzyme in comparison to non-Si-treated control plants. This study confirms that application of Si enhances resistance to BXW and may provide an alternative disease management strategy.

Silicon induces hormetic dose-response effects on growth and concentrations of chlorophylls, amino acids and sugars in pepper plants during the early developmental stage

“…Thus, the application of Si can differentially affect plant growth and development, depending on the internal mechanisms that the genotype has to metabolize this element (Ouellette et al, 2017). Biological responses of plants to Si can be a consequence of the apoplastic obstruction caused by excesive Si deposition in the cell wall (Coskun et al, 2019), which can trigger hormetic effects (Mburu et al, 2016;Agathokleous & Calabrese, 2020). In plants, Si is deposited as the solid, hydrated oxide SiO 2 •nH 2 O, known as silica gel, following polymerization of orthosilicic acid (Si(OH) 4 or H 4 SiO 4 ; the only form of Si available to plants) (Gropper & Smith, 2018).…”

“…In banana (Musa spp. L.), the application of 200 mg Si per week resulted in a stimulatory effect leading to the beneficial growth attributes, whereas treatments with 500 and 1,000 mg Si per week triggered inhibitory responses, resulting in detrimental effects evidenced by stunting and discoloration of the leaf edges (Mburu et al, 2016). Negative effects such as stunting, deformed flowers and delay in flowering were also observed in sunflowers at high concentrations of Si, thus suggesting Si application can vary from beneficial to detrimental depending on the source and concentration used (Kamenidou, Cavins & Marek, 2008;Kamenidou, Cavins & Marek, 2010).…”

Xanthomonas campestris pv. musacearum: a major constraint to banana, plantain and enset production in central and east Africa over the past decade

“…These recommendations are founded on the management principles used to deal with other banana bacterial wilt diseases, such as Moko disease (Thwaites et al, 2000). Recent reports have indicated that silicon concentrations above 200 mg/week induce resistance to BXW and thus may augment existing control measures through integrated Xcm management options (Mburu et al, 2016).…”

Exploration of silicon functions to integrate with biotic stress tolerance and crop improvement

“… Upgrade/maintain leaf cuticle thickening and leaf stomata crystals [ 121 ] Stalk borer ,, Decreased % stalks and length bored [ 122 ] Brown rust ,, Physical and biochemical [ 123 ] Euschistusheros Soybean ( Glycine max ) Upregulated non-preference and antibiosis resistances [ 124 ] Powdery mildew Arabidopsis ( Arabidopsis thaliana) Physio-biochemical activities increased and/or balanced [ 58 , 75 , 125 ] Black sigatoka Fusarium wilt Root rot Xanthomonas wilt Banana ( Musa spp.) ,, [ 126 – 129 ] Powdery mildew Barley ( Hordeum vulgare ) Improve physiological performance [ 130 ] Angular leaf spot Bean ( Phaseolus vulgaris ) ,, [ 131 ] Powdery mildew Black gram ( Vigna mungo ) Enhanced expression of genes [ 132 ] Dollar spot Bentgrass ( Agrostis stolonifera ) Improve physiological and biochemical characteristics [ 90 , 133 ] …”