Herbaspirillum sp. strain GW103 alleviates salt stress in Brassica rapa L. ssp. pekinensis.

Mutual interactions between plant and rhizosphere bacteria facilitate plant growth and reduce risks of biotic and abiotic stresses. The present study demonstrates alleviation of salt stress in Brassica rapa L. ssp. perkinensis (Chinese cabbage) by Herbaspirillum sp. strain GW103 isolated from rhizosphere soil of Phragmites australis. The strain was capable of producing plant beneficial factors, such as auxin, siderophore, and 1-aminocylopropane-1-carboxylic acid deaminase. Treatment of strain GW103 on Chinese cabbage under salt stress increased K(+)/Na(+) ratio in roots generating balance in the ratio of ion homeostasis and consequently contributed to the increase of biomass. In addition, root colonization potential of the strain was observed by green fluorescent protein (GFP)-tagging approach. These results strongly suggest the beneficial impact of strain GW103 by inducing the alleviation of salt stress and development of stress tolerance in Chinese cabbage via plant-microbe interaction.