Abstract：
Metabolic cross-feeding is a pervasive interaction between bacteria to acquire novel phenotypes. However, our current understanding of the survival mechanism for cross-feeding in cocultured bacterial biofilms under heavy-metal conditions remains limited. Herein, we found that Comamonas sp. A23 produces L-phenylalanine to activate the L-phenylalanine degradation pathway in Enterobacter sp. A11, enhancing biofilm formation and cadmium [Cd(II)] immobilization in A11. The genes responsible for L-phenylalanine-degradation (paaK) and cell attachment and aggregation (csgAD) are essential for biofilm formation and Cd(II) immobilization in A11 induced by L-phenylalanine. The augmentation of A11 biofilms, in turn, protects A23 under Cd(II) and H2O2 stresses. The plant-based experiments demonstrate that the induction of two rice Cd(II) transporters, OsCOPT4 and OsBCP1, by A11 and A23 enhances rice resistance against Cd(II) and H2O2 stresses. Overall, our findings unveil the mutual dependence between bacteria and rice on L-phenylalanine cross-feeding for survival under abiotic stress.
摘要：
代谢交叉进食是细菌之间普遍的相互作用，以获得新的表型。然而,我们目前对重金属条件下共培养细菌生物膜中交叉饲养的存活机制的理解仍然有限.在这里，我们发现Comamonassp.A23产生L-苯丙氨酸以激活肠杆菌中的L-苯丙氨酸降解途径。A11，增强生物膜的形成和镉[Cd(Ⅱ)]在A11中的固定。负责L-苯丙氨酸降解（paaK）和细胞附着和聚集（csgAD）的基因对于L-苯丙氨酸诱导的A11中的生物膜形成和Cd（II）固定至关重要。A11生物膜的增强，反过来,在Cd（II）和H2O2应力下保护A23。基于植物的实验表明，两种水稻Cd（II）转运蛋白的诱导，OsCOPT4和OsBCP1通过A11和A23增强了水稻对Cd（II）和H2O2胁迫的抗性。总的来说,我们的发现揭示了细菌和水稻之间在非生物胁迫下通过L-苯丙氨酸交叉饲养生存的相互依赖性。
