Arbuscular mycorrhizal association enhances drought tolerance potential of promising bioenergy grass (Saccharum arundinaceum retz.)

Abstract

The influence of arbuscular mycorrhizal fungi (AMF) (Glomus spp.) on some physiological and biochemical characteristics of bioenergy grass Saccharum arundinaceum subjected to drought stress was studied. The symbiotic association of Glomus spp. was established with S. arundinaceum, a potential bioenergy grass as evident from the increase in percentage of root infection and distribution frequency of vesicles when compared with non-arbuscular mycorrhizal plants. AMF-treated plants exhibited an enhanced accumulation of osmolytes such as sugars and proline and also increased protein content under drought. AMF association significantly increased the accumulation of non-enzymatic antioxidants like phenols, ascorbate and glutathione as well as enhanced the activities of antioxidant enzymes such as SOD (superoxide dismutase), APX (ascorbate peroxidase) and GPX (guaiacol peroxidase) resulting in reduced lipid peroxidation in S. arundinaceum. AMF symbiosis also ameliorated the drought-induced reduction of total chlorophyll content and activities of photosystem I and II. The maximum quantum efficiency of PS II (F v/F m) and potential photochemical efficiency (F v/F o) were higher in AMF plants as compared to non-AMF plants under drought stress. These results indicate that AMF association alleviate drought stress in S. arundinaceum by the accumulation of osmolytes and non-enzymatic antioxidants and enhanced activities of antioxidant enzymes, and hence, the photosynthetic efficiency is improved resulting in increased biomass production. AMF association with energy grasses also improves the acclimatization of S. arundinaceum for growing in marginal lands of drought-affected soils.

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Special issue in honour of Prof. Reto J. Strasser - Chlorophyll fluorescence, leaf gas exchange, and genomic analysis of chromosome segment substitution rice lines exposed to drought stress

“…Moreover, Fm of CSSL4 was higher than KDML105 and CSSL1 (Table 2). This phenomenon was similar to that found in rice under high light stress, thus, Chl a fluorescence parameters can be used to distinguish between the stress-tolerant and stress-susceptible lines (Mirshad andPuthur 2016, Faseela andPuthur 2017). The photosynthetic characteristics of CSSL1 and CSSL4 plants were compared to those of their parents, KDML105 and DH212, to investigate whether the maintenance of PSII efficiency under drought stress conditions at the seedling stage continued in the vegetative stage (i.e., tillering).…”

Arbuscular Mycorrhizal Fungi Mediate Drought Tolerance and Recovery in Two Contrasting Carob (Ceratonia siliqua L.) Ecotypes by Regulating Stomatal, Water Relations, and (In)Organic Adjustments

“…This difference in increase of protein levels could, at least partially, explain the ability of AMF to enhance the non-enzymatic antioxidant defense system [77,78]. Drought stress impedes plant growth through peroxidative damage [79]; nonetheless, AMF can reduce oxidative stress by increasing antioxidant enzyme activities in host plants [39,80,81]. MDA levels could indicate the magnitude of a plant's exposure to peroxidative damage caused by drought stress [82].…”