Research Projects

Occurrence fluoride (F-) in the earth crust contaminates groundwater leading to soil contamination. 77 districts within 20 Indian states are reportedly facing varing degrees of F- (Jha et al., 2013) viz., 0.12 to 24.17 mg l-1 in groundwater (Kumar and Gopal, 2000) and as high as 48 mg L-1 soil (Susheela, 1999). Soil contamination with F- has been attributed to several anthropogenic sources viz. superphosphate fertilization, groundwater irrigation and non-ferrous metal metallurgy (Wang et al., 2013). Among the 75 districts of Uttar Pradesh, 19 districts have high F- concentrations ranging from 1.5 to 43 mg L-1. The districts with the highest F- levels are Bahraich, Balrampur, and Shravasti, with concentrations above 10 mg L-1. Agriculture in India has shifted from rainfed (traditional) to mechanized irrigation using groundwaters (intensive modern). The groundwater containing F-, used in irrigation systems often contaminates farm soils, affecting crop production negatively and food safety (Senanayake and Mukherji, 2014). Fluoride uptake in plants is reported to take place through roots Cl- channels (CLC1 and CLC2) (Banerjee and Roychoudhury, 2019b). Similarly, impairment of plasma membrane H+/ATPase (P-H+/ATPase) activity was observed in semi-arid plant species grown under F− stress (Baunthiyal and Sharma, 2014). However, mechanism and rate of the uptake of F- by plant roots and its transportation to the aerial parts through different transporters, has not been carried out in details. Aquaporins, H+/F- antiporters, and ABC transporters are important transporters, that play a critical role in plant physiology, uptake and transport of nutrients, water, and other essential solutes. The enzymes belonging to the Krebs cycle like pyruvate dehydrogenase (PyrDH), malate dehydrogenase (MDH) and succinate dehydrogenase (SDH), are strongly inhibited under F- stress. Brassica juncea L. (Indian mustard), ranks second oilseed in India, contributing to 27.8% of India’s oilseed economy (Shekhawat et al., 2012). Mustard is cultivated in ~6.8 Mha, primarily in the northern plains of India comprising seven states i.e., Rajasthan, Uttar Pradesh, Haryana and, Madhya Pradesh, incidentally, these states has high F- in their groundwater (Chakraborti et al., 2016). Experimental study show (unpublished) the fatty acid (FAs) composition in the seeds of Brassica juncea exposed to F- stress changes. The level of erucic acid (EA) increased while the level of palmitic acid (PA) declined. Erucic acid leads to myocardial lipidosis due to reduction of contractile force of heart muscle (Abbott et al., 2003). On the other hand, PA is a saturated FA, is a building block of sphingolipid of brain and nerve cell membrane, which reduced in seeds of B. juncea under F- stress.