Summary: In this account of the fine structure of a nitrogen-fixing clover nodule the interactions between host and bacteria have been particularly considered. It is suggested that the bacterial infection is located between the paired membranes of the endoplasmic reticulum, i.e. within the intra-reticular space. It is shown that the plant membrane around the infection thread is continuous with the plasmalemma, but that it is fragmentary around the thread tip. Bacteria emerging from the infection thread remain surrounded by a plant membrane, and their subsequent fate (division or rapid swelling) is controlled by the condition of the host cytoplasm. Structural changes occurring in the cytoplasm, nuclear region and wall of emerged bacteria during their transition to the bacteroid form are described, and the development of peripheral carbohydrate platelets in the host cell is illustrated. Supporting observations on two types of ineffective nodules are discussed.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error