Ustilago maydis

Ustilago maydis is a pathogenic plant fungus that causes smut disease in maize and teosinte. The fungus is commonly referred to as corn smut in the United States and huitlacoche in Mexico.

Life Cycle

The life cycle of Ustilago maydis is complex, involving both asexual and sexual phases. The fungus exists primarily as a haploid yeast-like form that can reproduce asexually by budding. However, when two compatible strains come into contact, they can fuse to form a dikaryotic hyphae, which is the pathogenic form of the fungus. This form can penetrate the plant tissue, causing disease.

Disease Symptoms

The most noticeable symptom of Ustilago maydis infection is the formation of large, tumor-like galls on the ears, tassels, and stalks of the infected plant. These galls are initially white and soft, but as they mature, they become dark and hard, filled with black, powdery spores. When the galls burst, the spores are released and can infect other plants.

Economic Impact

While Ustilago maydis can cause significant yield losses in maize crops, the fungus is not always considered a pest. In Mexico, the galls caused by the fungus are considered a delicacy and are harvested and sold in markets as huitlacoche. This has led to some farmers intentionally infecting their crops to increase their income.

Control

Control of Ustilago maydis is primarily achieved through the use of resistant maize varieties. However, the fungus is highly adaptable and new strains can overcome resistance. Other control methods include crop rotation and the use of fungicides.

Research

Ustilago maydis is also an important model organism in fungal genetics and plant pathology. Its genome has been fully sequenced, providing valuable insights into fungal pathogenicity and plant-fungus interactions.

This article is a stub. You can help WikiMD by registering to expand it. Editing is available only to registered and verified users. WikiMD is a comprehensive, free health & wellness encyclopedia.