Drought and salinity limit crop yields throughout the world, and understanding the plant response mechanisms to these stresses can provide new insights into how to breed stress-tolerant genotypes. The leaf and root responses of five different licorice (Glycyrrhiza glabra) genotypes to drought and salinity stresses were investigated in field conditions, using control conditions and five stress levels (slight, moderate and intense drought; moderate and intense salinity). Parameters measured include leaf and root macronutrient concentrations, leaf photosynthetic pigment concentrations, leaf and root total antioxidant and phenolic compound concentrations and root concentrations of the secondary metabolites glycyrrhizin and glabridin. Drought and salt stresses caused progressive decreases in leaf photosynthetic pigment concentrations, accompanied by major changes in macronutrient concentrations in leaves (including increases in Na, Cl, K and Ca and decreases in Mg) and roots (including increases in Na and Cl, and decreases in K, Ca and Mg). Increases in leaf antioxidant enzyme activities (CAT and APX), leaf and root total antioxidant activity and total phenolics were also observed with both stresses. Multiple regression analysis suggest that it could be possible to make a fair estimation of the root glycyrrhizin concentrations using parameters that can be measured more easily, such as the leaf concentrations of macronutrients and photosynthetic pigments.

干旱和盐分限制了全世界的农作物产量，了解植物对这些胁迫的反应机制可以为如何培育耐逆基因型提供新的见解。五个不同甘草（甘草）的叶和根响应在田间条件下，使用控制条件和五个胁迫水平（轻度，中度和强烈干旱；中度和强烈盐度）研究了干旱和盐分胁迫的基因型。测得的参数包括叶和根的宏观营养素浓度，叶光合色素的浓度，叶和根的总抗氧化剂和酚类化合物的浓度以及次生代谢产物甘草甜素和加拉普丁的根浓度。干旱和盐胁迫导致叶片光合色素的浓度逐渐降低，并伴随着叶片中常量营养素含量的重大变化（包括Na，Cl，K和Ca的增加，而Mg减少）和根部（包括Na和Cl的增加，以及下降）在K，Ca和Mg中）。增加叶片抗氧化酶活性（CAT和APX），在两种胁迫下也观察到叶和根的总抗氧化剂活性和总酚类。多元回归分析表明，可以使用更容易测量的参数（例如叶片中的大量营养素和光合色素的浓度）来合理估算根甘草甜素的浓度。