Give the biochemical events occurring in the root nodule of a pulse plant. What is the end product? What is its fate?
Biochemical events occurring in the root nodule of a pulse plant are –
A) Rhizobium bacteria comes into contact with a susceptible root hair and begins to colonize the area of the roots.
B) The root hairs curl up after being invaded by the bacteria.
C) The infected thread formed in the roots carries the bacteria into the cortical tissue of the roots. The bacteria modify itself to Bacteroides which is rod-shaped, and as a result, the cortex and pericycle cells present in the roots divide.
D) The division of the two cells in the cortex leads to the formation of nodules.
E) A nodule is matured when it forms vascular tissues in continuation with the vascular tissues in the roots. Nitrogenase and leghaemoglobin present in the root nodules catalyze the conversion process in which atmospheric nitrogen is converted into ammonia. Ammonia is the end product of this fixation.
Equation: N2 + 8e- + 8H- + 16ATP 2NH3 + H2 + 16 ADP + 16Pi
Fate of Ammonia: Ammonia that is produced is converted into ammonium ions, which can be assimilated by plants. But since the ammonium ions are very toxic and should not be accumulated in plants, they get converted into amino acids through transamination and reductive amination.