​Influence of Native Endophytes on Early Stages Growth of Vigna radiata (Moong) under Salt Stress Condition

Abstract

Background: Green gram (Vigna radiata) also known as moong bean is an annually cultivated in East Asia, Southeast Asia and Indian subcontinent. V. radiata is very important source for the protein as in our regular diet and it proved essential amino acid such as phenylalanine, leucine, isoleucine, valine, lysine, arginine, methionine, threonine and tryptophan. Methods: Here, we studied the influence of seed endophytes on germination and development under salinity stress condition. Seeds were treated with sodium hypochlorite for 30 min under shaking condition at 100 rpm for surface sterilization and treated with 70% ethanol for 2 min and followed five times rinse with autoclaved water. Surface sterilised seeds were homogenised in autoclaved water with the help of mortal-pestle. Homogenised seed solution made serial dilution and spreaded over nutrient agar for endophytic bacterial growth. Seeds were treated with bacteriocide and fungicide to make endophytes free, followed by sown for germination at 0mM, 50mM, 100mM and 150mM NaCl concentration. Result: Endophyte free seedlings were more susceptible against salt stress over normal seedlings. Therefore endophyte free seedling shoot and root biomass was 23.5% and 65.7% lower than control seedling biomass at 0mM salt respectively, while root length was 70% lower than control seedling root at 0mM salt concentration. Proline content in shoot and root observed an increase with increase of salt concentration. At 0mM salt, proline content was 0.00782±0.00043 and 0.00648±0.00017 (µmol/mg) in root of normal and endophyte free seedling respectively, while in shoot, it was non-significant difference. Glycine betaine content found to be increasing upto 100mM, followed by decreasing at 150mM in both root and shoot tissue. Glycine betaine content in endophyte free and control seedling shoot was 74.2±2.5 and 96.0±2.73 (µg/200mg) respectively at 100mM salt concentration. This result suggests, not only heritable genomic DNA but also endophytes associated with seed are very much important for the seedling growth and development which is also finally helps to combat abiotic stress situation.