$nif$ genes occur in

The enzyme nitrogenase is:

What is nitrogen fixation?

$N_2$ fixation is

$N_2 + 8e^- + X + 16 ATP \rightleftharpoons 2NH_3 + Y + 16 ADP + 16 Pi$

We find that $Rhizobium$ forms nodules on the roots of leguminous plants. Also,$Frankia$,another microbe,forms nitrogen-fixing nodules on the roots of the non-leguminous plant $Alnus$. Can we artificially induce the property of nitrogen fixation in a plant,whether leguminous or non-leguminous?