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Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

brasilense when inoculated in Arabidopsis thaliana improved drought toler­

ance by upregulating ABA accumulation (Cohen et al., 2015). Trichoderma

isolated from Theobroma cacao induced drought tolerance by altering gene

expression pattern (Lata et al., 2018). In maize plant, Piriformospora indica

minimizes the effects of drought by enhanced proline accumulation, antioxi­

dant enzymes and also induced membrane stability (Xu et al., 2017).

3.4.1.2 ENDOPHYTES AND SALINITY TOLERANCE IN PLANTS

Increasing salinity in the soil is an emerging problem of the modern agricul­

tural system. It was estimated that by the year 2050, 50% of all the arable

lands will face severe saline condition (Zhang et al., 2019). In chickpea

plant salt tolerance is improved by Mesorhizobium ciceri and Bacillus

subtilis by decreasing oxidative stress and induced production of compatible

solute proline (Egamberdieva et al., 2017). In a study it was reported that

inoculation of tomato plant with Pseudomonas fluorescens and P. migulae

in a high saline condition induced salt stress tolerance by the activity of

ACC deaminase (Ali et al., 2014). Accumulation of excess amount of ROS

is a major problem plant generally faces during salinity stress. Endophytes

enhance the production of ROS scavengers like catalase, peroxidase, GRs,

and superoxide dismutases (SOD). In barley plant application of P. indica

minimizes the oxidative damages by enhancing antioxidant system in the

plant (Baltruschat et al., 2008). Achromobacter xylosoxidense promotes

growth under saline conditions by decreasing ethylene levels and inducing

antioxidant enzymes like SOD and APX in plants (Joe et al., 2012).

3.4.1.3 ENDOPHYTES-MEDIATED TEMPERATURE STRESS TOLERANCE

IN PLANTS

Temperature is one of the important factors for plant growth. Uncertain and

abnormal temperature exposure damages several crops worldwide. Various

studies have supported the fact that endophytes improved plant growth and

helped to minimize the impact of chilling and freezing stress (Zhang et al.,

2019). In a study when Lycopersicon esculentum was inoculated with three

bacterial endophyte Bacillus subtilis, B. cereus and Serratia sp. it increases

chilling stress tolerance by enhancing antioxidant enzyme system, accumu­

lating soluble sugar and induced expression of stress responsive genes (Wang

et al., 2016). In another report it was found that, grass species Dichanthelium