Ectomycorrhizal fungi reduce the light compensation point and promote carbon fixation of Pinus thunbergii seedlings to adapt to shade environments

Abstract

We examined the effects of three ectomycorrhizal (ECM) symbionts on the growth and photosynthesis capacity of Japanese black pine (Pinus thunbergii) seedlings and estimated physiological and photosynthetic parameters such as the light compensation point (LCP), biomass, and phosphorus (Pi) concentration of P. thunbergii seedlings. Through this investigation, we documented a new role of ectomycorrhizal (ECM) fungi: enhancement of the survival and competitiveness of P. thunbergii seedlings under low-light condition by reducing the LCP of seedlings. At a CO2 concentration of 400 ppm, the LCP of seedlings with ECM inoculations was 40–70 μmol photons m−2 s−1, significantly lower than that of non-mycorrhizal (NM) seedlings (200 μmol photons m−2 s−1). In addition, photosynthetic carbon fixation (Pn) increased with light intensity and CO2 level, and the Pn of ECM seedlings was significantly higher than that of NM seedlings; Pisolithus sp. (Pt)- and Laccaria amethystea (La)-mycorrhizal seedlings had significantly lower Pn than Cenococcum geophilum (Cg)-mycorrhizal seedlings. However, La-mycorrhizal seedlings exhibited the highest fresh weight, relative water content (RWC), and the lowest LCP in the mycorrhizal group. Concomitantly, ECM seedlings showed significantly increased chlorophyll content of needles and higher Pi concentrations compared to NM seedlings. Overall, ECM symbionts promoted growth and photosynthesis while reducing the LCP of P. thunbergii seedlings. These findings indicate that ECM fungi can enhance the survival and competitiveness of host seedlings under low light.

Ectomycorrhizal Inoculation Enhances the Salt Tolerance of Quercus mongolica Seedlings

“…In our study, the Chl content was higher in mycorrhizal Q. mongolica seedlings than in control group seedlings under NaCl treatment, and the decrease in the Chl content became less pronounced as the duration of stress increased, indicating that the chloroplasts of the mycorrhizal seedlings were less damaged. This is similar to the change in Chl content observed in the needles of P. thunbergii inoculated with C. geophilum under salt stress [42].…”

“…Under salt stress, plant chloroplasts tend to disintegrate, and the synthesis of chlorophyll and carotenoids is inhibited. Previous studies have shown that ectomycorrhizal fungi can increase the Chl content of P. thunbergii seedlings under salt stress [ 42 ]. In our study, the Chl content was higher in mycorrhizal Q. mongolica seedlings than in control group seedlings under NaCl treatment, and the decrease in the Chl content became less pronounced as the duration of stress increased, indicating that the chloroplasts of the mycorrhizal seedlings were less damaged.…”

Appraisal of Carbon Capture, Storage, and Utilization Through Fruit Crops

“…Therefore, apple production systems can be considered an important carbon sink in fruit culture (Wu et al, 2012). Similarly, many reports on carbon emission in various crops have been confirmed by other researchers globally (Piao et al, 2009;Bhatnagar et al, 2016;Marín et al, 2016;Shi et al, 2017;Khalsa et al, 2020). Kumar et al (2019) have used various models for estimating biomass of plants, i.e., 225 mg ha −1 with biomass accumulation and carbon storage reduced by roots followed by twigs and leaves and branches.…”

“…Literature available on carbon fluxes under fruit crop and NPP and GPP for horticultural crops, especially fruit crops (Ceschia et al, 2010;Marín et al, 2016;Shi et al, 2017;Khalsa et al, 2020), is summarized in Table 1. Fruit trees (woody, leaf, fruit, and roots) represent a valuable portion of land use in various areas and have an important role in capturing net carbon dioxide sink and storing carbon compounds in the permanent woody parts of the fruit tree (Scandellari et al, 2016;Chamizo et al, 2017;Tezza et al, 2019).…”

Evolutionary Insights Into Two Widespread Ectomycorrhizal Fungi (Pisolithus) From Comparative Analysis of Mitochondrial Genomes

“…The symbiosis of Pisolithus species with trees promotes the carbon and nutrient cycling of the forest ecosystem ( Cairney et al, 1989 ). In addition, the Pisolithus symbionts can promote the growth of plants, the absorption of mineral elements, and enhance the ability of plants to cope with abiotic stress, including drought, heavy metals and nutritional deficiencies ( Jourand et al, 2014 ; Shi et al, 2017 ; Sebastiana et al, 2018 ). Up to now, more than ten species have been described in the genus Pisolithus .…”