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Cell wall modifications of bean ( Phaseolus vulgaris ) cell suspensions during habituation and dehabituation to dichlobenil
Author(s) -
Encina Antonio,
Sevillano José Manuel,
Acebes José Luis,
Alvarez Jesús
Publication year - 2002
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2002.1140204.x
Subject(s) - middle lamella , phaseolus , cell wall , lamella (surface anatomy) , xyloglucan , polysaccharide , biology , cell , cell culture , biophysics , botany , biochemistry , anatomy , genetics
Bean ( Phaseolus vulgaris L.) cell suspensions were adapted for growth in 12 µ M dichlobenil (2,6‐dichlorobenzonitrile or DCB) by a stepwise increase in the concentration of the inhibitor in each subculture. Non‐tolerant suspensions (I 50 = 0.3 µ M ) gave rise to single cells or small clusters while tolerant cell suspensions (I 50 = 30 µ M ) grown in DCB formed large clusters. The cells in these clusters were surrounded by a thick and irregular cell wall with a lamellate structure and lacking a differentiated middle lamella. Analysis of habituated cell walls by Fourier transform infrared spectroscopy and cell wall fractionation revealed: (1) a reduced amount of cellulose and hemicelluloses, mainly xyloglucan (2) qualitative and quantitative differences in pectin levels, and (3) a non‐crystalline and soluble β‐1,4‐glucan. When tolerant cells were returned to medium lacking DCB, the size of the cell clusters was reduced; the middle lamella was only partly formed, and the composition of the cell wall gradually reverted to that obtained with non‐tolerant cells. However, dehabituated cells (I 50 = 12 µ M ) were 40‐fold more tolerant to DCB than non‐tolerant cells and were only 2.5‐fold more sensitive than tolerant cells.