Glomeromycota consists of arbuscular mycorrhizal fungi (AMF), a major monophyletic group characterized by what relationship with other organisms?
1. They cause athlete's foot, yeast, and worse infections in their human hosts.
2. They provide key nutrients to tree, grass, and shrub roots in exchange for sugar.
3. They can cause blight in crops and trees.
4. They are predatory on amoeba and other unicellular protists.