Plant Physiology Laboratory, Faculty of Biological and Environmental Sciences, University of León, E-24071 León, Spain; Centre for Plant Biotechnology and Genomics (CBGP), Politechnical University of Madrid, E-28223 Madrid, Spain.
J Integr Plant Biol. 2015 Apr;57(4):357-72. doi: 10.1111/jipb.12346.
Maize (Zea mays L.) suspension-cultured cells with up to 70% less cellulose were obtained by stepwise habituation to dichlobenil (DCB), a cellulose biosynthesis inhibitor. Cellulose deficiency was accompanied by marked changes in cell wall matrix polysaccharides and phenolics as revealed by Fourier transform infrared (FTIR) spectroscopy. Cell wall compositional analysis indicated that the cellulose-deficient cell walls showed an enhancement of highly branched and cross-linked arabinoxylans, as well as an increased content in ferulic acid, diferulates and p-coumaric acid, and the presence of a polymer that stained positive for phloroglucinol. In accordance with this, cellulose-deficient cell walls showed a fivefold increase in Klason-type lignin. Thioacidolysis/GC-MS analysis of cellulose-deficient cell walls indicated the presence of a lignin-like polymer with a Syringyl/Guaiacyl ratio of 1.45, which differed from the sensu stricto stress-related lignin that arose in response to short-term DCB-treatments. Gene expression analysis of these cells indicated an overexpression of genes specific for the biosynthesis of monolignol units of lignin. A study of stress signaling pathways revealed an overexpression of some of the jasmonate signaling pathway genes, which might trigger ectopic lignification in response to cell wall integrity disruptions. In summary, the structural plasticity of primary cell walls is proven, since a lignification process is possible in response to cellulose impoverishment.
通过逐步适应纤维素生物合成抑制剂敌草隆（DCB），获得了纤维素含量降低至 70%的玉米（Zea mays L.）悬浮培养细胞。纤维素缺乏伴随着细胞壁基质多糖和酚类物质的显著变化，这一点通过傅里叶变换红外（FTIR）光谱得到了揭示。细胞壁成分分析表明，纤维素缺陷细胞壁表现出高度支化和交联的阿拉伯木聚糖的增强，以及阿魏酸、对香豆酸和 p-香豆酸含量的增加，以及对间苯三酚呈阳性染色的聚合物的存在。与此一致，纤维素缺陷细胞壁的 Klason 型木质素增加了五倍。纤维素缺陷细胞壁的硫代酸解/GC-MS 分析表明存在一种木质素样聚合物，其愈创木基/松柏基比率为 1.45，与短期 DCB 处理引起的严格意义上的应激相关木质素不同。对这些细胞的基因表达分析表明，木质素单体生物合成的基因表达过度。对应激信号通路的研究表明，一些茉莉酸信号通路基因的表达过度，这可能会触发细胞壁完整性破坏时的异位木质化。总之，由于对纤维素匮乏的响应，初生细胞壁的结构可塑性得到了证明，木质化过程是可能的。
