Plant pathogenic bacteria are mostly:
1.  Gram + Non-spore forming
2.  Gram – Non-spore forming
3.  Gram + spore forming
4.  Gram (–) spore forming

The difference in gram ⊕ and gram $\Theta$ bacteria is due to:
1. Cell wall
2. Cell membrane
3. Ribosome
4. Cytoplasm