DOI: 10.36347/sjavs.2017.v04i05.001

Pages: 175-185

Abstract: Varieties of mechanisms have been developed by plants to adapt, cope with, defend and ward off different arrays of invasion; this includes aggressive invasions from pathogenic organisms that cause diseases. The plant upon sensing danger activates certain signaling pathways within them, this leads to the induced gene expressions with different defensive roles. Their system that activates immunity within and the ability to detect microbial pathogens will be presented. For an infection to occur there must be a close ecological relationship that will be established between the host plants and the pathogens. Attention is also drawn to how pathogens produce plant penetrating mechanisms to invade and bring down the plants defensive structures and the various types of plant pathogens that invade host plants. This paper also reviews the current knowledge of defense mechanisms in host plants among which includes cell wall fortification, defense genes and its activation, secondary metabolites synthesis and defense hormones generation. Resistance and defense can be manipulated to develop varieties of crops which easily fight and inhibit infectious pathogenic stress, as it can also be used as a part of integrated disease management for productive crop production. The knowledge derived from this work together with other research studies in this area will help to draw highlight on the major components in plant defense responses and to design strategies to enhance resistance to pathogen invasion in plants.