The symbiotic relationship between plants and microbes can generate low voltage at the plant rhizosphere (soil around the roots) region and this can be harnessed to stimulate the growth of the plant, say scientists of the CSIR-Indian Institute of Chemical Technology (IICT).
In the latest research work, scientists S. Venkata Mohan and D.K. Yeruva reported a nature-based method to stimulate plant growth and photosynthetic activity by channelising the electron flux in the plant rhizosphere area to create an electrical stimulus in their study on two model legumes — Vigna Radiata (mung bean) and Cicer Aarietinum (chick pea).
The in situ bio-potential was harnessed by strategically placing electrode assemblies in the plant rhizosphere where microbes and plant root cells prevail, which creates an ideal environment for microbial metabolism releasing protons and electrons leading to a potential gradient.
This low electric field has led to accelerated growth parameters with relatively higher plant height, node number, leaf area, flowering, podding, fresh and dry weight by the end of the vegetative phase, said the study.
Early flowering and podding showcased the rapid transitioning of the vegetative to the reproductive phase by 18 days, compared to the usual 40 days. The low electrical stimuli regulate plant physiological activities, influencing gene expression, nutrient flow, Co2 fixation, and gas exchange during photosynthesis.
Improved electron mobility was observed leading to the active transfer of nutrients and electrons across the cell membranes to the chloroplast pigments. This improved the rate of electron transport, and stimulated the production of various enzymes in the photosynthetic reaction centre.
This also resulted in improved carbon fixation efficiency while the presence of electrodes influenced gene expression patterns and abundance of different kinds of proteins enabling active transport of water, small molecules and nutrients.
Scientists said the technique has immediate and promising prospects for nursery-raised plantlets, transplanted crops, and for augmenting phytoremediation for effective pollution removal. Using low-cost electrodes and conductive materials within the soil rhizosphere could make this process feasible under field conditions.
The use of electrical stimulation for plant growth though at a nascent stage, could become a viable method for sustainable agriculture with further research though different plants may respond differently to electrical stimulation, observed the scientists.
The study, “In situ self-induced electrical stimulation to plants: Modulates morphogenesis, photosynthesis and gene expression in Vigna radiata and Cicer arietinum”, was published in the recent edition of Bio-electrochemistry Journal.
