Arbuscular mycorrhizal fungi and foliar phosphorus inorganic supply alleviate salt stress effects in physiological attributes, but only arbuscular mycorrhizal fungi increase biomass in woody species of a semiarid environment

Abstract

Salinity may limit plant growth especially in arid and semiarid regions. Arbuscular mycorrhizal fungi (AMF) and the supply of inorganic phosphorus (Pi) could alleviate the negative effects of such stress by improvement in stomatal conductance, photosynthesis and biomass. The aim of this study is to evaluate the ecophysiological performance of Cenostigma pyramidale (Tul.) E. Gagnon & G. P. Lewis (Fabaceae) in a greenhouse under salinity conditions in combination with the supply of AMF and leaf Pi. The experiment was conducted in a factorial design considering two levels of salinity (+NaCl and -NaCl), two levels of AMF (+AMF and -AMF) and two levels of leaf Pi supply (+Pi and -Pi). The variables gas exchange, leaf primary metabolism, dry biomass and nutrients were measured. Plants with AMF under non-saline conditions presented a high photosynthesis and biomass. In saline conditions, AMF promoted lower decrease in photosynthesis, high shoot dry matter and low content of leaf and root Na+ and Cl-. Plants treated with leaf Pi increased biomass and photosynthetic pigments under both conditions and accumulated more Cl- in shoots under salinity conditions. When combined, AMF * Pi increased photosynthesis only in non-saline conditions. Plants under salinity conditions without AMF and Pi had higher decreases in gas exchange and high content of Cl- in roots. Therefore, C. pyramidale plants improved their metabolism under both growth conditions in the presence of AMF, Pi or a combination of both. However, the greatest increases in growth and tolerance to salinity occurred in the isolated presence of AMF.

Arbuscular Mycorrhizal Fungi Effectively Enhances the Growth of Gleditsia sinensis Lam. Seedlings under Greenhouse Conditions

“…Macronutrients, especially P, N, and K, are of vital importance in the growth of plants. Numerous studies have reported that AMF increased nutrient (P, N, K) uptake by various plant species under particular conditions [23,28,29]. Mycorrhizae create links between roots and the soil, with the fungal hyphae being functionally analogous to fine root hairs, and acquire nutrients (especially relatively immobile elements such as P) by altering the uptake dynamics, whereas mycelia extend the effective absorption surfaces of plant roots [30].…”

Stomatal Conductance and Morphology of Arbuscular Mycorrhizal Wheat Plants Response to Elevated CO2 and NaCl Stress

“…In the present study, the g s of the adaxial and abaxial leaf surfaces in the AM wheat plants was higher than in non-AM plants. AM plants often show higher g s than non-AM plants under unstressed conditions, elevated CO 2 concentration and salt stress (Aroca et al, 2013 ; Goicoechea et al, 2014 ; Augé et al, 2016 ; Frosi et al, 2018 ). A meta-analysis by Augé et al ( 2015 ) indicated that the g s in AM plants was increased by an average of 24% compared with non-AM plants for sufficiently watered and drought-stressed plants.…”

“…Some studies have reported that AMF influences the stomatal behavior of leaves exposed to salinity stress or elevated CO 2 regime. Under salinity stress, AM plants showed higher g s and lower intercellular CO 2 concentration and water potential, hereby maintaining a favorable gas exchange capacity and water use efficiency (Sheng et al, 2008 ; Evelin et al, 2009 ; Kapoor et al, 2013 ; Frosi et al, 2018 ). At elevated CO 2 , the response of g s to AM symbiosis varies.…”

Arbuscular mycorrhizal fungi (AMF) enhance the tolerance of Euonymus maackii Rupr. at a moderate level of salinity

“…Our research showed that the enhanced nutrient absorption observed with AMF inoculation was manifested in the N, P and K contents. Many researchers hold the opinion that the improvement of plant P acquisition is the most important mechanism in mycorrhizal plants under salt stress [42], such as Frosi et al [43] found that P can be transported into the root via protoplasmic circulation, greatly reducing the transport resistance and increasing the transport speed for the continuous mycelium of AMF. However, some other studies found that even if mycorrhizal and nonmycorrhizal plants have a similar P status under unstressed conditions, mycorrhizal plants still grow better than nonmycorrhizal plants under salt stress [44].…”