Drenched Silicon Suppresses Disease and Insect Pests in Coffee Plant Grown in Controlled Environment by Improving Physiology and Upregulating Defense Genes

Abstract

Plant disease and insect pests are major limiting factors that reduce crop production worldwide. The ornamental indoor cultivation cash crop dwarf coffee Punica arabica ‘Pacas’ is also troubled by these issues. Silicon (Si) is one of the most abundant elements in the lithosphere and positively impacts plant health by effectively mitigating biotic and abiotic stresses. Several studies have shown that Si activates plant defense systems, although the specific nature of the involvement of Si in biochemical processes that lead to resistance is unclear. In our study, Si significantly promoted the growth and development of dwarf coffee seedlings grown in plant growth chambers. More than that, through natural infection, Si suppressed disease and insect pests by improving physiology (e.g., the strong development of the internal structures of roots, stems, and leaves; higher photosynthetic efficiency; more abundant organic matter accumulation; the promotion of root activity; the efficient absorption and transfer of mineral elements; and various activated enzymes) and up-regulating defense genes (CaERFTF11 and CaERF13). Overall, in agriculture, Si may potentially contribute to global food security and safety by assisting in the creation of enhanced crop types with optimal production as well by mitigating plant disease and insect pests. In this sense, Si is a sustainable alternative in agricultural production.

Advances in the Involvement of Metals and Metalloids in Plant Defense Response to External Stress

“…At the physiological level, the addition of Si promotes various plant organ activities, including structural architecture, photosynthetic efficiency, and enzyme synthesis [ 153 ]. When plants face attacks from arthropod pests, the synergic action between Si and JA induces the accumulation of secondary metabolites known as herbivore-induced plant volatiles (HIPV).…”

“…Notably, the emission of HIPV can attract the predator Helicoverpa armigera to Dicranolaius bellulus and the predator Manduca sexta to Geocoris spp., subsequently deterring pest attacks on plants [ 156 , 157 ]. At the molecular level, Si can upregulate defense genes to enhance plant resistance against insect attacks effectively [ 153 ]. The introduction of Si amendments also induces the transcript levels of genes responsible for Si transport and plant defense regulation.…”