Foliar heavy metal uptake, toxicity and detoxification in plants: A comparison of foliar and root metal uptake

Abstract

Anthropologic activities have transformed global biogeochemical cycling of heavy metals by emitting considerable quantities of these metals into the atmosphere from diverse sources. In spite of substantial and progressive developments in industrial processes and techniques to reduce environmental emissions, atmospheric contamination by toxic heavy metals and associated ecological and health risks are still newsworthy. Atmospheric heavy metals may be absorbed via foliar organs of plants after wet or dry deposition of atmospheric fallouts on plant canopy. Unlike root metal transfer, which has been largely studied, little is known about heavy metal uptake by plant leaves from the atmosphere. To the best of our understanding, significant research gaps exist regarding foliar heavy metal uptake. This is the first review regarding biogeochemical behaviour of heavy metals in atmosphere-plant system. The review summarizes the mechanisms involved in foliar heavy metal uptake, transfer, compartmentation, toxicity and in plant detoxification. We have described the biological and environmental factors that affect foliar uptake of heavy metals and compared the biogeochemical behaviour (uptake, translocation, compartmentation, toxicity and detoxification) of heavy metals for root and foliar uptake. The possible health risks associated with the consumption of heavy metal-laced food are also discussed.

Effects of cadmium-induced stress on essential oil production, morphology and physiology of lemon balm (Melissa officinalis L., Lamiaceae)

“…Cd directly or indirectly affects photosynthesis by reducing or preventing the uptake of elements like Zn, Fe and Cu, and in turn blocking enzyme activation and respiration (Seregin and Ivanov, 2001). Therefore, destructive effects of heavy metals on some physiological processes of plants such as photosynthesis, water relations, and mineral nutrition (Zouari et al, 2016) As the duration and degree of the stress increases, these structures gradually degrade, and a morphological, physiological and biochemical decay process which ends with the plant's death begins (Shahid et al, 2017). In the present study, the number of stomata on both surfaces of the lemon balm leaves decreased parallel to the increase in the concentration of Cd.…”

Multielements determination and metal transfer investigation in herb medicine Bupleuri Radix by inductively coupled plasma‐mass spectrometry

“…In Shanxi, the coal industry is vigorously developing; air and soil pollution is therefore widespread in the province (Wu, Zhang, Pei, Chen, & Zheng, 2014). As many studies have shown, the difference in geographical environments is an important cause behind element levels in plants (Kaličanin, Velimirović, Arsić, & Đorđević, 2014; Shahid et al., 2017; Wu et al., 2014); the uptake of metal elements by plants is influenced by various factors, including the nature of soil, climate, and agriculture practices (Hu et al., 2017; Imtiaz et al., 2016). The elements (including Mn, Ni, and Cu) in Gansu were shown to be at higher levels than in the Shanxi provinces.…”

Avaliação Da Qualidade De Um Afluente Utilizado Para Irrigação Na Região Semiárida De Pernambuco (Nordeste Do Brasil)

“…O consumo de plantas com elevados teores de metais como Pb, Cu, Zn, Cr e Mn é uma importante via de contaminação para seres humanos e animais e a absorção destes compostos por vegetais pode variar de acordo com a espécie, idade fisiológica e exposição destes organismos (SHAHID et al, 2017). Em seres humanos metais como cobre podem desencadear doenças neurodegenerativas, como a doença de Alzheimer, distúrbios na eritropoiese e a exposição a níveis elevados de manganês pode causa desordem neurológica chamada manganismo que tem semelhanças com a doença de Parkinson (MOHMAND et al, 2015).…”