TY - JOUR AU - NI, Qiu-Dan AU - ZOU, Ying-Ning AU - WU, Qiang-Sheng AU - HUANG, Yong-Ming PY - 2013/12/06 Y2 - 2024/03/29 TI - Increased Tolerance of Citrus (Citrus tangerina) Seedlings to Soil Water Deficit after Mycorrhizal Inoculation: Changes in Antioxidant Enzyme Defense System JF - Notulae Botanicae Horti Agrobotanici Cluj-Napoca JA - Not Bot Horti Agrobo VL - 41 IS - 2 SE - Research Articles DO - 10.15835/nbha4129218 UR - https://www.notulaebotanicae.ro/index.php/nbha/article/view/9218 SP - 524-529 AB - <p>Arbuscular mycorrhizal fungi (AMF) can enhance tolerance of plants to soil water deficit, whereas morphological observations of reactive oxygen species and antioxidant enzyme system are poorly studied. The present study thereby evaluated temporal variations of the antioxidant enzyme system in citrus (<em>Citrus tangerina</em>) seedlings colonized by Glomus etunicatum and<em> G. mosseae</em> over a 12-day period of soil drying. Root colonization by <em>G. etunicatum</em> and <em>G. mosseae</em> decreased with soil drying days from 32.0 to 1.0% and 50.1 to 4.5% in 0-day to 12-day, respectively. Compared to the non-AM controls, the AMF colonized plants had significantly lower tissue (both leaves and roots) hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and superoxide anion radical (O2•–) concentrations during soil water deficit, whereas 1.03–1.92, 1.25–1.84 and 1.18–1.69 times higher enzyme activity in superoxide dismutase, peroxidase (POD) and catalase. In situ leaf H2O2 and root POD location also showed that AM seedlings had less leaf H<sub>2</sub>O<sub>2</sub> but higher root POD accumulation. Furthermore, significantly higher root infection and antioxidant enzymatic activities in plants colonized with <em>G. mosseae</em> expressed than with<em> G. etunicatum</em> during the soil drying. These results demonstrated that the AMs could confer greater tolerance of citrus seedlings to soil water deficit through an enhancement in their antioxidant enzyme defence system whilst an decrease level in H<sub>2</sub>O<sub>2</sub> and O2•–.</p> ER -