Plant Immunity and Potential of Plant Extracts in Management of Parasitic Nematodes

Abstract
One major challenge that agricultural production faces is the presence of plant-parasitic nematodes in crop fields. Plant-parasitic nematodes cause serious plant physical injuries, the inability of plants to acquire nutrients from the soil, and weaken the plant immune system. However, plants respond in several ways by producing hormones, anti-nematocidal proteins, repellents, nemastatic compounds, or inhibiting the feeding cell formation and development that minimize attack and injuries by the nematodes. Sometimes these mechanisms fail and therefore plant growers have to use plant management practices to prevent and suppress the presence of parasitic nematodes. The development and use of synthetic nematicides have limitations associated with costs and environmental pollution. Therefore, the use of plant extracts that contains anthelmintic compounds has proved to be successful in suppressing parasitic nematodes while maintaining environmental safety for living organisms. However, the relationship between plant immunity and the applications of plant extracts has not been well documented. It is against this background that this minireview explains the mechanism of plant immunity and the potential of plant extracts in enhancing plants to resist and suppress parasitic nematodes. The research progress and challenges of using the plant extracts have also been discussed thus creating potential areas of future research on applications of plant extracts in parasitic nematodes management. Furthermore, this minireview has recommended the use of sustainable integrated management of plant-parasitic nematodes approach.