Impact of Arbuscular Mycorrhizal Fungi on Photosynthesis, Water Status, and Gas Exchange of Plants Under Salt Stress–A Meta-Analysis

Abstract

Soil salinization is one of the most serious abiotic stress factors affecting plant productivity through reduction of soil water potential, decreasing the absorptive capacity of the roots for water and nutrients. A weighted meta-analysis was conducted to study the effects of arbuscular mycorrhizal fungi (AMF) inoculation in alleviating salt stress in C 3 and C 4 plants. We analyzed the salt stress influence on seven independent variables such as chlorophyll, leaf area, photosynthetic rate ( Amax ), stomatal conductance ( Gs ), transpiration rate ( E ), relative water content (RWC), and water use efficiency (WUE) on AMF inoculated plants. Responses were compared between C 3 and C 4 plants, AMF species, plant functional groups, level of salinity, and environmental conditions. Our results showed that AMF inoculated plants had a positive impact on gas exchange and water status under salt stress. The total chlorophyll contents of C 3 plants were higher than C 4 plants. However, C 3 plants responses regarding Gs, Amax , and E were more positive compared to C 4 plants. The increase in G s mainly maintained E and it explains the increase in Amax and increase in E . When the two major AMF species ( Rhizophagus intraradices and Funnelliformis mosseae ) were considered, the effect sizes of RWC and WUE in R. intraradices were lower than those in F. mosseae indicating that F. mosseae inoculated plants performed better under salt stress. In terms of C 3 and C 4 plant photosynthetic pathways, the effect size of C 4 was lower than C 3 plants indicating that AMF inoculation more effectively alleviated salt stress in C 3 compared to C 4 plants.

The Effect of Arbuscular Mycorrhizal Fungi on Photosystem II of the Host Plant Under Salt Stress: A Meta-Analysis

“…Random-effects model meta-analyses were conducted for each of the categorical independent variables to test the effect size of AMF inoculation on chlorophyll fluorescence under salt stress using MetaWin2.1 software [23], following the calculation method described by Chandrasekaran et al [21]. Effect sizes were considered to be significant if their bias-corrected bootstrap 95% confidence intervals (CI) did not include zero.…”

“…Meta-analysis is an effective way to merge data from independent studies, which can be used to estimate the effect sizes and find potentially contributing variations across similar studies [26]. Previous studies have used meta-analysis to unveil the effects of AMF inoculation on host plants under salt stress, including AMF's ability to increase P and K assimilation, antioxidant enzyme activities, gas exchange, and ionic adjustment by changing the root and mycorrhizal morphological traits [19][20][21]. In the present meta-analysis study, we provided sufficient evidence to confirm that AMF inoculation has a significant impact on the performance of PSII in host plants under salt stress.…”

“…Auge et al performed a meta-analysis and reported that AMF inoculation could improve ion balance and osmotic adjustment to relieve salt stress [20]. In addition, a weighted meta-analysis was also conducted to explore the effects of AMF inoculation on gas exchange in C3 and C4 plants under salt stress [21]. Many studies came to the conclusion that AM symbiosis alters the photosynthetic capacity of host plants [1,7].…”

Improving plant growth and alleviating photosynthetic inhibition from salt stress using AMF in alfalfa seedlings

“…AMF inoculation can maintain the K + / Na + balance under salt stress (Evelin et al 2012;Garg and Bhandari 2016a). AMF infection effectively improves plant photosynthetic capacity (Birhane et al 2012;Chandrasekaran et al 2019;Li et al 2019), and stomatal conductance under salt stress (Lin et al 2017). AMF also improves salt tolerance by reducing non-photochemical quenching of rice leaves under salt stress (Porcel et al 2015).…”

Nondestructive Evaluation of Inoculation Effects of AMF and Bradyrhizobium japonicum on Soybean under Drought Stress From Reflectance Spectroscopy

“…The results of Auge et al [6] and Abdel-Salam et al [9] provide evidences that AMF improved drought tolerance of rose plants. Many researchers have found that a series of leaf parameters including chlorophyll a and chlorophyll b contents, LCC, LWC, and leaf area of AMF inoculated plants had increased, compared to non-inoculated plants under abiotic stresses [10][11][12]. Given the sensitivity of LCC and LWC to the inoculation, they are considered as the main biochemical parameters to indicate the inoculation effects of AMF and BJ on plant growth.…”