Soybean root growth inhibition and lignification induced by p-coumaric acid

Benzoxazolin-2(3H)-one inhibits soybean growth and alters the monomeric composition of lignin

“…Indeed, previous results revealed that the reduced growth of soybean roots caused by hydroxycinnamic derivative allelochemicals was associated with an effective performance of the phenylpropanoid pathway and premature cell wall lignification. [21][22][23] Increases in the content of H, G and S monomers and HCGCS, which is a reasonable estimate of the degree of condensation of the lignin polymer, 7 suggest that structural properties of the cell wall can be adversely affected by BOA. It is clear that such effects can significantly limit cell expansion and compromise plant growth.…”

Allelopathic Compounds as Oxidative Stress Agents: Yes or NO

“…The second enzyme POX, acts at the last step of phenypropanoid pathway forming H, G and S lignin units. Exogenously applied caffeic acid (1 and 2 mM), ferulic acid (1 mM), and p-coumaric acid (at !0.5 mM) significantly inhibited soybean root growth (Bubna et al 2011;Zanardo et al 2009;dos Santos et al 2008). These cinnamic acid derivatives have similar modes of action in acceptor plants.…”

“…Cinnamic acid derivatives (e.g., ferulic, caffeic, and p-coumaric acids) usually induce premature lignification of root cell wall (dos Santos et al 2008;Zanardo et al 2009). Phenolics can be channeled into the phenylpropanoid pathway contributing to the excess synthesis of lignin monomers and in this way increasing lignification (dos Santos et al 2008).…”

“…Influx of more phenolic compounds into phenylpropanoid pathway increased lignin production via enlarged amount of lignin monomer H, G and S in case of caffeic acid; H, G for p-coumaric acid and G for ferulic acid. In spite of modified lignin monomer composition, PAL activity has been reduced (Bubna et al 2011;Zanardo et al 2009). The activity of POX significantly increased after caffeic, ferulic and p-coumaric acid treatment with simultaneous decline in H 2 O 2 concentration (Bubna et al 2011;dos Santos et al 2008;Zanardo et al 2009).…”

“…In spite of modified lignin monomer composition, PAL activity has been reduced (Bubna et al 2011;Zanardo et al 2009). The activity of POX significantly increased after caffeic, ferulic and p-coumaric acid treatment with simultaneous decline in H 2 O 2 concentration (Bubna et al 2011;dos Santos et al 2008;Zanardo et al 2009). Cinnamic acid derivatives accumulate in cell wall which supports the idea that apoplastic POX may be directly engaged in cell wall lignification (Kovácik et al 2009).…”