Root Growth and Enzymes Related to the Lignification of Maize Seedlings Exposed to the Allelochemical L-DOPA. (14th November 2013)

• Record Type: Journal Article
• Authors: Siqueira-Soares, Rita de Cássia; Soares, Anderson Ricardo; Parizotto, Angela Valderrama; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, Osvaldo
• Other Names: Bais H. P. Academic Editor.; Cresti M. Academic Editor.
• Is Part Of: TheScientificWorldjournal. Volume 2013(2013)
• Publication Date: 2013-11-14
• Subjects: Science -- Periodicals; Technology -- Periodicals; Medicine -- Periodicals; 505
• DOI: 10.1155/2013/134237
• Languages: English
• ISSNs: 2356-6140

Abstract

Abstract : L-3, 4-Dihydroxyphenylalanine (L-DOPA) is a known allelochemical exuded from the roots of velvet bean ( Mucuna pruriens L. Fabaceae). In the current work, we analyzed the effects of L-DOPA on the growth, the activities of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), and peroxidase (POD), and the contents of phenylalanine, tyrosine, and lignin in maize ( Zea mays ) roots. Three-day-old seedlings were cultivated in nutrient solution with or without 0.1 to 2.0 mM L-DOPA in a growth chamber (25°C, light/dark photoperiod of 12/12, and photon flux density of 280 μ mol m −2 s −1 ) for 24 h. The results revealed that the growth (length and weight) of the roots, the PAL, TAL, and soluble and cell wall-bound POD activities decreased, while phenylalanine, tyrosine, and lignin contents increased after L-DOPA exposure. Together, these findings showed the susceptibility of maize to L-DOPA. In brief, these results suggest that the inhibition of PAL and TAL can accumulate phenylalanine and tyrosine, which contribute to enhanced lignin deposition in the cell wall followed by a reduction of maize root growth.