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.
