The habituation of cell cultures to cellulose biosynthesis inhibitors such as dichlobenil (DCB) represents a valuable tool to improve our knowledge of the mechanisms involved in plant cell wall structural plasticity. Maize cell lines habituated to lethal concentrations of DCB were able to grow through the acquisition of a modified cell wall in which cellulose was partially replaced by a more extensive network of arabinoxylans. The aim of this work was to investigate the phenolic metabolism of non-habituated and DCB-habituated maize cell cultures. Maize cell cultures were fed [14C]cinnamate and the fate of the radioactivity in different intra-protoplasmic and wall-localized fractions throughout the culture cycle was analyzed by autoradiography and scintillation counting. Non-habituated and habituated cultures did not markedly differ in their ability to uptake exogenous [14C]cinnamic acid. However, interesting differences were found in the radiolabeling of low- and high-Mr metabolites. Habituated cultures displayed a higher number and amount of radiolabeled low-Mr compounds, which could act as reserves later used for polysaccharide feruloylation. DCB-habituated cultures were highly enriched in esterified [14C]dehydrodiferulates and larger coupling products. In conclusion, an extensive and early cross-linking of hydroxycinnamates was observed in DCB-habituated cultures, probably strengthening their cellulose-deficient walls.
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机译:细胞培养物对纤维素生物合成抑制剂(如二氯苯酚(DCB))的适应性代表了一种有价值的工具,可以提高我们对植物细胞壁结构可塑性机制的认识。适应致死浓度DCB的玉米细胞系能够通过获得修饰的细胞壁而生长,在该细胞壁中,纤维素被更广泛的阿拉伯木聚糖网络部分取代。这项工作的目的是研究非习惯和DCB习惯的玉米细胞培养物中的酚类代谢。玉米细胞培养物中加入了[ 14 sup> C]肉桂酸酯,并通过放射自显影和闪烁计数分析了整个培养周期中不同质内质和壁局部级分中放射性的命运。非习惯性和习惯性文化在吸收外源[ 14 sup> C]肉桂酸的能力上没有显着差异。然而,在低和高M r sub>代谢物的放射性标记中发现了有趣的差异。习性培养物显示出更高数量和数量的放射性标记的低M r sub>化合物,这些化合物可以用作后来用于多糖阿魏酸酯化的储备。 DCB习惯的培养物高度富含酯化的[ 14 sup> C]脱氢蝶呤和较大的偶联产物。总之,在DCB习惯的培养物中观察到了羟基肉桂酸酯的广泛而早期的交联,这可能增强了其纤维素不足的壁。
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