Altered carbon status in Glycine max hairy roots induced by Agrobacterium rhizogenes

Plants fix CO₂ into carbohydrates through photosynthesis, and various organisms interact with plants to obtain carbohydrates. Agrobacterium rhizogenes is a soil bacterium known as a plant pathogen that induces hairy root disease. Through A. rhizogenes-plant interactions, transfer-DNA (T-DNA) of the Ri plasmid is inserted into the host plant genome, leading to excessive formation of hairy roots and the synthesis of opines that are carbon and nitrogen sources for A. rhizogenes. In this study, we analyzed the carbohydrate contents in soybean (Glycine max) hairy roots. We found that the starch content was strongly increased in hairy roots, whereas the glucose was significantly decreased. On the other hand, no significant differences were observed in sucrose levels between the main roots and hairy roots of A. rhizogenes-inoculated plants. This result suggests that A. rhizogenes infection caused a change in primary carbon metabolism in the host plant cells.