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Role of Endophytes, Plant Growth Promoting Rhizobacteria

cucumber plant two fungal endophytes Penicillium sp. and Phoma glomerata

increased biomass yield by improved uptake of nutrients like magnesium,

calcium, and potassium and also reduced sodium ion toxicity under salinity

and drought stress (Waqas et al., 2012). An overall mechanism of endophyte­

mediated stress tolerance is presented in Figure 3.3.

FIGURE 3.3 Endophytes-mediated abiotic stress tolerance in plants.

3.4.1.1 ENDOPHYTES AND DROUGHT TOLERANCE IN PLANT

Drought is one of the main stressors responsible for low productivity of

many important crops. However, many plants evolved protective mecha­

nisms against drought stress. In this regard, endophytic microorganisms play

a significant role in adopting drought. Endophytes colonized rice, tomato,

panic grass and dune grass utilized less water under drought stress than

plants which do not have endophytic infection. Endophyte helps to accumu­

late different solutes in the plant tissue and also reduce water conductance

and transpiration by altering leaf morphology (Malinowski & Beleskey,

2000). Rhizobium etli a bacterial endophyte when inoculated in Phaseolus

vulgaris induced stress tolerance under drought condition by production of

trehalose-6-phosphate synthase enzyme (Suarez et al., 2008). Azospirillum