Figure 1.

Schematic representation of IKK/NκFB-like signaling pathway regulating NO levels in tomato seedlings. The sites of action of the pharmacological inhibitors as derived from existing mammalian models are indicated. The putative role of native SHR as a repressor of a NFκB-like molecule is also indicated. The mutation in shr presumably results in the removal of this negative regulator thereby resulting in the constitutive transcriptional activation of a NOS-like enzyme. The increase in NOS-like activity leads to increase in NO levels in the mutant resulting in inhibition of root elongation.