Preliminary Studies on Etiology of Summer Squash Bacterial Soft Rot Disease Preliminary Studies on Etiology of Summer Squash Bacterial Soft Rot Disease Erwinia carotovora ssp. carotovora Infection Induced “Defense Lignin” Accumulation and Lignin Biosynthetic Gene Expression in Chinese Cabbage (Brassica rapa L.ssp. pekinensis) Isolation and identification of four new Erwinia carotovora subsp. carotovora strains Simplification of vacuole structure during plant cell death triggered by culture filtrates of Erwinia carotovora