Synergistic effect of endophytic selenobacteria on biofortification and growth of Glycine max under drought stress

Abstract

Some of the plant endophytes have ability to accumulate selenium from soil and provide it to the plant in turn benefiting plant's growth, such microbes are known as selenobacteria. Application of such endophytic selenobacteria may improve selenium biofortification in Glycine max crops under drought stress. Under present research we studied such phenomenon and claim the use of selenobacteria to have significant biotechnological application in agriculture. For this study, we isolated bacterial endophytes from the various tissues of Ricinus communis plant that was originally experimented for selenium enrichment. These isolates were assessed to reduce sodium selenite into elemental selenium and the efficient strains were tested on the growth of soybean plant grown under drought stress. Impact of selenobacteria on biofortification of selenium in plant tissues of Glycine max were assessed by HG-AAS. Moreover, selenobacteria also improved the growth of Glycine max plants was also observed under drought. Molecular identification using 16S rRNA gene sequence analysis suggested the potential strains MGT9, MGT16 and MGT18 to be Paraburkholderia megapolitana, Alcaligenes faecalis and Stenotrophomonas maltophilia respectively. From all the strains under study, Paraburkholderia megapolitana MGT9 was found to be most effective in improving the growth of Glycine max plant under drought along with showing exceptional selenium fortification that was 7.4 folds higher when compared to control. There was also an increase in the activity of plant stress markers, SOD, POD, CAT and GR in the fruit of Glycine max treated with MGT9 suggestive of better management of oxidative stress in plant induced by drought.