Investigating the microbial stimulated phytoremediation potentials of Sunflower in cadmium contaminated soil

Abstract

With the rapid rise in the soil environmental pollution, it is crucial to develop sustainable strategies for effective soil cleanup. Hyperaccumulator plants are long term energy sources and an excellent choice for remediating soil enriched with heavy metals. Often such plants, when exposed to heavy metals hyperaccumulate them in their vital organs leading to poor quality yield thus reducing their nutritional value. Sunflower is an important oil seed crop that can hyperaccumulate heavy metals into its tissues which when consumed by living beings enter the food chain. Microbe assisted bioremediation is a sustainable solution for reducing cadmium toxicity I plants and rending them suitable for consumption. This research has been designed to analyze various combinations of microbial inoculation for reducing cadmium toxicity in plants. For experiments six different treatments compensated with bacteria with and without cadmium were established alongside a negative control (plant only) and a positive control (plant + cadmium) using freshly developed sunflower hybrid SMH1900K. Analysis of morphophysiological responses reveals that the cadmium stress causes impairment in plant growth and disrupts its physiological performance while bacteria co-inoculation elevates the toxicity by reducing the cadmium toxicity. Biochemical profiles of different treatment groups showed that bacterial amendment mitigate cadmium stress by modulating the activities of antioxidant enzymes. Gene expression profiling of cadmium chelator peptides shows their production is significantly reduced in the coincoulation treatments because of reduced cadmium bioavailability. Research findings suggest that the coincoualtion showed a superior performance to heavy metal stress. This proves that coioculation of strains can elevate heavy metal stress in hyperaccumulator plants which can be in helpful in reducing heavy metal toxicity various agricultural crops.