Effects of Arbuscular Mycorrhizal Fungi on Growth and Physiological Performance of Catalpa bungei C.A.Mey. under Drought Stress

Abstract

Catalpa bungei C.A.Mey. is a common ornamental timber species. Its survival and growth are greatly affected by water scarcity in arid and semi-arid areas of Northwest China. Evidence suggests arbuscular mycorrhizal fungus (AMF) may improve plant drought resistance. However, there is limited information on the systematic effects of AMF on drought resistance in C. bungei seedlings. Here, a pot experiment was used to explore the effects of inoculation with the AMF Rhizophagus intraradices on the growth and physiological performance of C. bungei under different water treatment conditions. Three water levels and two mycorrhizal inoculation treatments were used with factorial design. The results showed that drought stress noticeably affected the growth and physiological performance of C. bungei seedlings. However, inoculation with R. intraradices significantly ameliorated the growth, and alleviated the effects of drought stress. The growth parameters of AMF-inoculated seedlings significantly increased regardless of water status. AMF changed the biomass allocation in seedlings by reducing the root mass ratio (RMR) and root/shoot ratio. AMF-inoculated seedlings displayed higher gas exchange parameters, photosynthetic pigment concentrations, specific leaf area (SLA), but lower specific leaf weight (SLW), regardless of water status. AMF alleviated drought-induced oxidative stress by attenuating the excess generation of reactive oxygen species (ROS), especially H2O2 and O2−, in leaves. Inoculation with AMF under drought stress also dramatically augmented indole-3-acetic acid (IAA) and gibberellins (GA3) levels and the IAA/abscisic acid (ABA) and GA3/ABA ratios, but reduced ABA and zeatin (ZT) levels in leaves. AMF symbiosis improved root morphology and promoted the absorption of nitrogen (N) and phosphorus (P) in seedlings. We conclude that inoculation with R. intraradices is potentially useful for afforestation and cultivation of C. bungei in Northwest China. Furthermore, AMF improved soil structure by increasing the glomalin-related soil protein (GRSP) contents and the proportion of macro-aggregates (0.25–0.5 mm) in the rhizosphere soil.

Alterations to arbuscular mycorrhizal fungal community composition is driven by warming at specific elevations

“…Mycorrhizal fungi have a vital impact on the composition of microbial and plant communities ( van der Heijden et al, 2015 ; Genre et al, 2020 ), and AMF symbiosis can also improve nutrient and water supply to host plants ( Parniske, 2008 ; Song et al, 2015 ; Wang, Pokharel & Chen, 2019 ; Sarmiento-López et al, 2020 ; Shi et al, 2020a ). Positive plant water relations by AMF have been demonstrated to improve plant drought resistance ( Chen et al, 2020 ) by enhancing the uptake of N and P under drought stress ( Hashem et al, 2018 ), alleviate soil water stress ( Mickan et al, 2016 ), and promote plants to deplete soil moisture to alleviate plant water stress ( Hardie, 1985 ). Many studies also suggested that AMF may promote plant growth through enhance tolerance to abiotic stress, such as drought and salinity ( Yang, Koide & Zhang, 2016 ; Xiang et al, 2016 ; Mckibben & Henning, 2018 ; Higo et al, 2019 ; Zhang et al, 2019a , 2019b ; Wu et al, 2021 ).…”

Effects of Severe Drought Stress on Some Physiological and Biochemical Parameters of AMF Inoculated C. arietinum

“…Under drought conditions, amount of some important macroelements such as phosphorus (P), calcium (Ca) and microelements such as iron (Fe), manganese (Mn), nickel (Ni), copper (Cu) and zinc (Zn) (Table1) increased by mycorrhizal symbiosis. Chen et al (2020) explained these results by extraradical hyphal network formed in the soil upon AMF colonization. P and Ca are the main mineral elements for plant growth.…”

Mycorrhizal Symbiosis for Better Adaptation of Trees to Abiotic Stress Caused by Climate Change in Temperate and Boreal Forests

“…Similarly, the water-use efficiency is in most cases improved in colonized plants, as observed in AM poplar and in ECM pine and oak trees exposed to drought (Li L. et al, 2021;Li Y. et al, 2021). This could be related to a better modulation of stomata closure and abscisic acid concentration and signaling (Wang et al, 2017;Ouledali et al, 2018;Chen et al, 2020).…”