Soybean Ureases, but Not That of Bradyrhizobium japonicum, Are Involved in the Process of Soybean Root Nodulation

作者：Medeiros Silva Monica; Franck William L; Borba Marcela P; Pizzato Sabrina B; Strodtman Kent N; Emerich David W; Stacey Gary; Poacco Joseph C^*; Carlini Celia R

来源：Journal of Agricultural and Food Chemistry, 2014, 62(16): 3517-3524.

DOI：10.1021/jf5000612

• B. japonicum
• soybean urease
• leghemoglobin
• nitrogen fixation

Ureases are abundant in plants, bacteria, and in the soil, but their role in signaling between soybean and soil microorganisms has not been investigated. The bacterium Bradyrhizobium japonicum forms nitrogen-fixing nodules on soybean roots. Here, we evaluated the role(s) of ureases in the process of soybean nodulation. Chemotaxis assays demonstrated that soybean and jack bean ureases were more chemotactic toward bacterial cells than the corresponding plant lectins. The eu1-a,eu4 soybean, deficient in urease isoforms, formed fewer but larger nodules than the wild-type, regardless of the bacterial urease phenotype. Leghemoglobin production in wild-type plants was higher and peaked earlier than in urease-deficient plants. Inhibition of urease activity in wild-type plants did not result in the alterations seen in mutated plants. We conclude that soybean urease(s) play(s) a role in the soybean-B. japonicum symbiosis, which is independent of its ureolytic activity. Bacterial urease does not play a role in nodulation.

• 出版日期2014-4-23