Engineer Nodule Organogenesis

The symbiotic nodule provides a location suitable for Nitrogen fixation and nutrient exchange

Why Engineer an Organ?

The nodule essentially amplifies the number of cells that can be colonised by the nitrogen-fixing bacteria, increasing the overall levels of nitrogen fixation.

Nodules show some similarities to lateral roots but clear differences exist in the mature structure.

24 hour old Lateral Root
72 hour old Lateral Root
24 hour old Nodule
72 hour old Nodule

In both lateral organ types, plant hormones initiate cell division in the inner root tissues. Proliferating cells are organised into a primordia that will emerge from the outer cell layers. During development, the shapes and functions of the organs diverge.

Organ conversion is already possible in certain circumstances. Shown below is a nodule that has converted to a lateral root in a loss function mutant.

Engineering Scheme

Organ conversion is already possible in certain circumstances. Shown below is a nodule that has converted to a lateral root in a loss function mutant.

We know that changes in the plant hormones cytokinin and auxin underpin the development of a nodule. These same hormones are involved in lateral root development and we are exploring whether comparable perturbations to cytokinin and auxin in a cereal can drive cell divisions. Alternatively, we are exploring whether we can hijack lateral root development in cereals to provide an environment suitable for accommodating nitrogen-fixing bacteria. In both scenarios we envision utilising many aspects intrinsic to cereal root development for production of nodules or psuedonodules in cereal roots.