Plant growth, ion accumulation, and antioxidant enzymes of endophyte-infected and endophyte-free tall fescue to salinity stress

Abstract

Endophyte-mediated salinity tolerance is largely unknown in tall fescue [Schedonorus arundinaceus (Schreb.)]. The experiment was designed to characterize growth, ion accumulation, and antioxidant metabolism of tall fescue infected by the endophyte Epichloë coenophiala to different levels of salinity stress. Endophyte-infected (E +) and endophyte-free (E−) tall fescue (cv Kentucky 31) plants were exposed to 10 d of 0 (unstressed control), 100 and 200 mM NaCl treatments in a greenhouse, respectively. Salinity stress caused reductions in plant height, leaf fresh weight (LFW), leaf dry weight (LDW), and leaf water content (LWC), and increased Na + concentration, but E + plants had significantly higher LFW, LDW, and LWC under both NaCl treatments and lower Na + than E− plants under 200 mM NaCl. Salinity stress decreased K + and Mg 2+ and did not alter P, and increased Ca 2+ in E + plants and caused no change in Ca 2+ in E− plants; however, endophyte had no effects on these elements. Chlorophyll fluorescence (Fv/Fm), malondialdehyde (MDA) concentration, and activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) remained unchanged in E + plants, but Fv/Fm was reduced and MDA level and enzyme activities were elevated in E− plants under 200 mM NaCl, where E + plants had significantly higher Fv/Fm and lower MDA, SOD, and APX activities than E− plants. Peroxidase activities increased in E + plants under 200 mM NaCl and in E− plants under both NaCl treatments. The results indicated that endophyte promoted salinity tolerance in tall fescue through maintaining higher growth and photochemical efficiency and lowering Na + accumulation and lipid peroxidation. The significantly induced antioxidant enzyme activities and lipid peroxidation in E− plants suggested a possible enhanced oxidative injury in endophyte-free plants exposed to a high level of salinity stress.

Endophytic Fungus <i>Glomerella</i> sp. JP4 Alleviated the Phytotoxic Effects in Rice Seedlings Exposed to Aluminum Stress

“…SOD, POD and CAT activity was higher in the EI plants compared to the EF plants under Al stress, which is consistent with our previous study on the endophyte-infected rice under Cd stress [20]. Pan et al also reported that endophytic infection increased antioxidant enzyme activity in tall fescue under salinity stress [36]. Plants combat the adverse effects of stress by increasing the activity of antioxidant enzymes [37].…”

Liquid fertilizers on photochemical efficiency and gas exchange in yellow passion fruit under saline stress

“…However, this can limit the entry of CO 2 and its assimilation (Seifikalhor et al, 2019). Despite that, the increases in Fv and Fw indicate full operation of the PSII reaction centers and stability of the photosynthetic apparatus under water restrictions (Pan et al, 2021). The values in Figure 2C suggest no photoinhibition damage to the PSII in yellow passion fruit seedlings treated with liquid fertilizers, as the range from 0.75 to 0.85 indicates optimal functioning of the photosynthetic apparatus (Ramos et al, 2022).…”

“…Irrigation with high-salinity water leads to a gradual accumulation of salts in substrates, thereby compromising the stabilization and productivity of yellow passion fruit seedlings (Bezerra et al, 2014). A quality decline in seedlings is attributed to osmotic factors, as roots struggle to absorb water from substrate, and ionic factors, causing nutritional imbalances and specific toxicity, especially due to sodium (Na + ) and chloride (Cl -) ions (Zörb et al, 2019;Arif et al, 2020;Pan et al, 2021).…”

Accumulation of Alkaloids in Different Tall Fescue KY31 Clones Harboring the Common Toxic Epichloë coenophiala Endophyte under Field Conditions

“…While general climatic conditions affect the overall fitness of the genotypes, specific environmental factors likely condition the yearly alkaloid levels, as seen in the ergot alkaloid levels observed between years in the current study. It is well documented that abiotic factors such as pasture management, fertilization and water availability influence the accumulation of the different alkaloids [49][50][51][52][53][54]. Simultaneously, the presence of the endophyte has also been demonstrated to change the physiological and metabolic profile of plants harboring endophytes when compared to endophyte-free plants [51,[55][56][57][58][59].…”