Impact of Moisture Stress and Bacillus altitudinis FD48 on Physiological Modulation and Seed Germination in Rice (Oryza sativa L.)

Sivakumar Uthandi,Shobana Narayanasamy

doi:10.29321/maj.2020.000331

Abstract

The impact of moisture stress tolerant Bacillus altitudinis FD48 in promotingseed germination and physiological phenomenon under water deficit wasevaluated. Rice seeds (Var CO51) biotized with B.altitudinis FD48 enhancedthe seed germination and seedling vigor index by 51.05% followed byMethylobacterium sp.,(37.3%) moisture stress seedlings (-0.7 Mpa osmoticpotential). Plant biomass, accumulation of proline and compatible sugars alsoincreased in FD48 treated seeds under moisture stress. Further, the alphaamylase activity also accelerated with increase in moisture stress intensity. GCMSprofiling of bacterial primed seed exudates revealed 35 diverse compoundsbelonging to the class viz., sugars, aminoacids, organic acids, flavones, prenollipids and fatty acids. The B. altitudinis FD48 primed seeds alone releasedmethoxy flavone which may act as a lure for recruiting beneficial rhizosphericbacteria. Hence, this study implies that seed priming with B.altitudinis FD48is a promising approach for enhancing seed germination and seedlingestablishment in rice for drought prone areas and subsequent recruitment ofbeneficial bacteria that promotes plant growth and fitness.

Highlights

Rice (Oryza Sativa L.) is an important cereal crop, serves as a staple food for more than half billion people across the globe contributing 20%80% of daily calorie requirement
The present study aims to demonstrate the efficacy of B. altitudinis FD48 on seed germination under induced moisture stress
Bacillus altitudinis FD48 used in this study, was obtained from the Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore

Summary

Introduction

Rice (Oryza Sativa L.) is an important cereal crop, serves as a staple food for more than half billion people across the globe contributing 20%80% of daily calorie requirement. The present study aims to demonstrate the efficacy of B. altitudinis FD48 on seed germination under induced moisture stress. 10 germinated seeds from each treatment with different stress levels with PEG 6000 (0, 5, 10, 15, 20, 25) were homogenized in 1:4 w/v distilled water using chilled pestle and mortar. Osmotic stress imposed seeds treated with FD48 and Methylobacterium sp at -0.7 MPa accounted for 44% and 32% increase in germination percent respectively over uninoculated control.

Results

Conclusion