Farmers, gardeners, and botanists have long observed that plant diseases tend to flare up during periods of high humidity, particularly after rainfall. Humid conditions help bacteria enter plant leaves, and once inside, certain species create a waterlogged internal environment known as “water-soaking.” This dilutes the plant’s defenses and essentially turns the leaf into a bacterial incubator. Central to this process is the hormone abscisic acid (ABA), which controls the release of water via tiny leaf pores called stomata.
How plants fight back against bacteria that promote waterlogging in leaves
