Abstract
A Tn5-induced mutant strain (TL68) of Mesorhizobium ciceri unable to grow with ammonium as the sole nitrogen source was isolated and characterized. Unlike its wild-type parent (strain TAL620), the mutant had an absolute dependence on serine to grow. Cloning of the DNA region containing Tn5 and sequence analysis showed that Tn5 was inserted into the gene coding for 3-phosphoglycerate dehydrogenase, which catalyses the first step in the serine biosynthetic pathway. The role of serine biosynthesis of M. ciceri in the establishment of nitrogen-fixing symbiosis with chickpea (Cicer arietinum L) was investigated using the mutant TL68. The serA(-) mutant (TL68) was unable to elicit the development of efficient nodules on the roots of Cicer arietinum L. The addition of serine to the plant-growth medium restored the ability of the mutant to nodulate Cicer arietinum, and the nodules were able to fix nitrogen.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.