Role of rice heme oxygenase in lateral root formation

Lateral roots (LRs) play important roles in increasing the absorptive capacity of roots as well as to anchor the plant in the soil. In rice, exposure to auxin, methyl jasmonate (MJ), apocynin, and CoCl₂ has been shown to increase LR formation. This review provides evidence showing a close link between rice heme oxygenase (HO) and LR formation. The effect of auxin and MJ is nitric oxide (NO) dependent, whereas that of apocynin requires H₂O₂. The effect of CoCl₂ on the LR formation could be by some other pathway unrelated to NO and H₂O₂. This review also highlights future lines of research that should increase our knowledge of HO-involved LR formation in rice.