Soybean (Glycine max) Root Lignification Induced by Ferulic Acid. The Possible Mode of Action

Abstract

Ferulic acid, in the form of feruloyl CoA, occupies a central position as an intermediate in the phenylpropanoid pathway. Due to the allelopathic function, its effects were tested on root growth, H(2)O(2) and lignin contents, and activities of cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) and peroxidase (POD, EC 1.11.1.7) from soybean (Glycine max (L.) Merr.) root seedlings. Three-day-old seedlings were cultivated in half-strength Hoagland's solution (pH 6.0), with or without 1.0 mM ferulic acid in a growth chamber (25 degrees C, 12/12 hr light/dark photoperiod, irradiance of 280 micromol m(-2) s(-1)) for 24 or 48 hr. Exogenously supplied ferulic acid induced premature cessation of root growth, with disintegration of the root cap, compression of cells in the quiescent center, increase of the vascular cylinder diameter, and earlier lignification of the metaxylem. Moreover, the allelochemical decreased CAD activity and H(2)O(2) level and increased the anionic isoform PODa5 activity and lignin content. The lignin monomer composition of ferulic acid-exposed roots revealed a significant increase of guaiacyl (G) units. When applied jointly with piperonylic acid (an inhibitor of the cinnamate 4-hydroxylase, C4H), ferulic acid increased lignin content. By contrast, the application of 3,4-(methylenedioxy) cinnamic acid (an inhibitor of the 4-coumarate:CoA ligase, 4CL) with ferulic acid did not. Taken together, these results suggest that ferulic acid may be channeled into the phenylpropanoid pathway (by the 4CL reaction) and, further, may increase the lignin monomer amount solidifying the cell wall and restricting the root growth.

Ferulic acid and derivatives: molecules with potential application in the pharmaceutical field

“…PAL, phenylalanine ammonia-lyase; C4H, cinnamate-4-hydroxylase; 4CL, 4-coumarate:CoA ligase; HCT, hydroxycinnamoyl CoA: quinate/shikimate hydroxycinnamoyl transferase; C3H, coumarate-3-hydroxylase; CCoAOMT, caffeoyl coenzyme A 3-O-methyltransferase; CCR, cinnamoyl CoA reductase; F5H, ferulate 5-hydroxylase; COMT, caffeic acid 3-O-methyltransferase; CAD, cinnamyl alcohol dehydrogenase; ALDH, aldehyde dehydrogenase (Santos et al, 2008). 1997; Zhao et al, 2005;Mattila et al, 2005;Matilla et al, 2006;Liyana, Shahidi, 2006;Mattila et al, 2007).…”

“…Ferulic acid (FA) is an important biological and structural component of the plant cell wall. Due to its ability to stop radical chain reactions by resonance followed by polymerization, FA offers protection against UV-radiation and is responsible for cross-linking polysaccharides and other cell wall polymers (Sánchez et al, 1996;Kroon et al, 1999, Santos et al, 2008.…”

“…Ferulic acid (FA) is an important biological and structural component of the plant cell wall. Due to its ability to stop radical chain reactions by resonance followed by polymerization, FA offers protection against UV-radiation and is responsible for cross-linking polysaccharides and other cell wall polymers (Sánchez et al, 1996;Kroon et al, 1999, Santos et al, 2008.FA can be obtained from plant cell walls via alkaline chemical (Taniguchi et al, 1999) or biotechnological treatments employing feruloyl esterases (EC 3.1.1.73) a subclass of the carboxylesterases produced by microorganisms that are able to hydrolyze ester bonds formed between cell wall polysaccharides and FA or its dimers, but more research is necessary to make biotechnological route economically attractive Kroon et al, 1999;Wong, 2005; Damásio et al, 2012). These enzymes have been produced and purified from a wide range of microorganisms, including bacteria and fungi such as Pseudomonas fluorescens, Penicilium funiculosum, Talaromyces stipitatus, Aspergillus niger (Faulds et al, 1995;De Vries et al, 2002).…”

Transcription factors expressed in soybean roots under drought stress

“…For example, reduction in lignin content which is a phenylpropanoid compound may promote growing of the roots. On the other hand, increases in lignin content may reinforce cell walls for mechanical strength and for water conductance (Andrade, 2006;Fan et al, 2006;dos Santos et al, 2008). These are both desirable characteristics for acquisition of drought stress tolerance depending on when the changes in lignifications occur.…”

Allelopathic Compounds as Oxidative Stress Agents: Yes or NO

“…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).…”