Effects and Mechanisms of Arsenic on Plant Growth and Physiological- Biochemical Characteristics: A Review.

The intensive mining activities, industrial sewage discharges and agricultural sewage irrigations lead to large amounts of arsenic (As) entering into soils, inducing increased soil As pollution. Arsenic and phosphorus (P), belonging to the same group, exhibit similar chemical properties and behaviors. Arsenic is taken up by plants via root P transporters. After entering into plants, As competes and replace P in compounds, and binds with sulfhydryl groups causing protein inactivation, affecting plant growth and normal physiological metabolism. However, studies showed that As at specific levels affected plant physiological processes and plant growth. Therefore, this paper reviews the differences of As content and distribution in plants, illustrates the effects and mechanisms of As on plant biomass, nutrient uptake, growth or metabolism-related physiological and biochemical indexes (endogenous hormones, photosynthesis parameter, malondialdehyde, antioxidant enzymes, and osmotic substances), and rhizosphere properties and microbial community of plant growth promotion bacteria. The information helps to better understand the mechanisms for As-promoted plant growth in hyperaccumulators, and provides theoretical supports to develop strategies to improve plants As detoxicity and resistant ability. [ABSTRACT FROM AUTHOR]