What is the primary function of a necrotroph in relation to its host?

The primary function of a necrotroph in relation to its host is to kill host cells for its survival. Necrotrophic pathogens, such as certain fungi and bacteria, rely on the death of host tissues in order to obtain nutrients. They produce enzymes and toxins that break down host tissue, leading to cell death, which then allows them to absorb the released nutrients. This process can cause significant damage to the host organism.

In contrast, mutualistic or beneficial organisms would aim to provide nutrients or stimulate growth in the host instead of harming it. This is not the case for necrotrophs, as their survival is directly linked to the destruction of living plant cells. The relationship is one of parasitism, where the pathogen benefits at the expense of the host, making the action of killing host cells a critical aspect of their life cycle.