RESUMO
The governing principles and suites of genes for lateral elongation or incorporation of new cell wall material along the length of a rod-shaped cell are well described. In contrast, relatively little is known about unipolar elongation or incorporation of peptidoglycan at one end of the rod. Recent work in three related model systems of unipolar growth (Agrobacterium tumefaciens, Brucella abortus, and Sinorhizobium meliloti) has clearly established that unipolar growth in the Hyphomicrobiales order relies on a set of genes distinct from the canonical elongasome. Polar incorporation of envelope components relies on homologous proteins shared by the Hyphomicrobiales, reviewed here. Ongoing and future work will reveal how unipolar growth is integrated into the alphaproteobacterial cell cycle and coordinated with other processes such as chromosome segregation and cell division.
Assuntos
Brucella abortus , Brucella abortus/crescimento & desenvolvimento , Brucella abortus/genética , Brucella abortus/metabolismo , Sinorhizobium meliloti/genética , Sinorhizobium meliloti/crescimento & desenvolvimento , Sinorhizobium meliloti/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/crescimento & desenvolvimento , Agrobacterium tumefaciens/metabolismo , Parede Celular/metabolismo , Peptidoglicano/metabolismo , Divisão CelularRESUMO
Bacillus subtilis uses swarming motility and biofilm formation to colonize plant roots and form a symbiotic relationship with the plant. Swarming motility and biofilm formation are group behaviours made possible through the use of chemical messengers. We investigated whether chemicals applied to plants would interfere with the swarming motility and biofilm-forming capabilities of B. subtilis in vitro. We hypothesized that pesticides could act as chemical signals that influence bacterial behaviour; this research investigates whether swarming motility and biofilm formation of B. subtilis is affected by the application of the commercial pesticides with the active ingredients of neem oil, pyrethrin, or malathion. The results indicate that all three pesticides inhibit biofilm formation. Swarming motility is not affected by the application of pyrethrin or malathion, but swarm expansion and pattern is altered in the presence of neem oil. Future studies to investigate the mechanism by which pesticides alter biofilm formation are warranted.
