Frei Michael
Division of Abiotic Stress Tolerance in Crops, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Karlrobert-Kreiten Straße 13, 53115 Bonn, Germany.
ScientificWorldJournal. 2013 Nov 14;2013:436517. doi: 10.1155/2013/436517.
Lignin is a plant component with important implications for various agricultural disciplines. It confers rigidity to cell walls, and is therefore associated with tolerance to abiotic and biotic stresses and the mechanical stability of plants. In animal nutrition, lignin is considered an antinutritive component of forages as it cannot be readily fermented by rumen microbes. In terms of energy yield from biomass, the role of lignin depends on the conversion process. It contains more gross energy than other cell wall components and therefore confers enhanced heat value in thermochemical processes such as direct combustion. Conversely, it negatively affects biological energy conversion processes such as bioethanol or biogas production, as it inhibits microbial fermentation of the cell wall. Lignin from crop residues plays an important role in the soil organic carbon cycling, as it constitutes a recalcitrant carbon pool affecting nutrient mineralization and carbon sequestration. Due to the significance of lignin in several agricultural disciplines, the modification of lignin content and composition by breeding is becoming increasingly important. Both mapping of quantitative trait loci and transgenic approaches have been adopted to modify lignin in crops. However, breeding goals must be defined considering the conflicting role of lignin in different agricultural disciplines.
木质素是一种对多种农业学科具有重要意义的植物成分。它赋予细胞壁刚性，因此与植物对非生物和生物胁迫的耐受性以及机械稳定性相关。在动物营养中，木质素被认为是饲料中的一种抗营养成分，因为它不易被瘤胃微生物发酵。就生物质的能量产出而言，木质素的作用取决于转化过程。它所含的总能比其他细胞壁成分更多，因此在热化学过程（如直接燃烧）中能提高热值。相反，它会对生物能量转化过程（如生物乙醇或沼气生产）产生负面影响，因为它会抑制细胞壁的微生物发酵。作物残茬中的木质素在土壤有机碳循环中起着重要作用，因为它构成了一个难降解的碳库，影响养分矿化和碳固存。由于木质素在多个农业学科中的重要性，通过育种来改变木质素含量和组成变得越来越重要。数量性状位点定位和转基因方法都已被用于改变作物中的木质素。然而，在确定育种目标时，必须考虑木质素在不同农业学科中的矛盾作用。
