No expression is universal across plants. Genetically they are too varied and adapted to too many environmental conditions. So the expression of any issue, logically is varied depending on the plant species background.

That’s why anyone that works with or knows a lot about plants uses qualifying terms like “usually, generally, most common, etc”. It’s always an educated guess.

Browning of leaves could be a sign of root rot. It also could be a sign of salt buildup in the soil. Insect feeding on the roots, different nutrient deficiencies/excesses, herbicide/pesticide damage, or even reactions to temperature, light and humidity. Yeah…