Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria that help plants grow better without the need for harmful chemicals. They colonize the roots of plants and improve growth by producing substances like nitrogen-fixing enzymes and growth hormones. PGPR also help plants fight off diseases by producing antibiotics and other protective compounds. By using PGPR, farmers can promote healthy plant growth and reduce the use of chemical fertilizers and pesticides, leading to more sustainable agriculture.