Manganese accumulation and plant physiology behavior of <i>Camellia oleifera</i> in response to different levels of potassium fertilization
Fangming Yu, Xueru Wang, Yawei Yao, Jiamin Lin, Yuanyuan Huang, Dongyu Xie, Kehui Liu, Yi Li
Abstract
The effects of potassium (K) fertilization (KCl, analytically pure; 0, 60, 200, and 400 mg kg−1) on the growth and Mn accumulation of Camellia oleifera in two types of Mn-contaminated soils were investigated. The potential mechanisms underlying the impacts of K fertilization were explored. C. oleifera accumulated high amounts of Mn in both soil conditions. The addition of K fertilizer decreased the soil pH and promoted Mn accumulation in C. oleifera. However, the plant biomass decreased significantly under the high level of K fertilization (400 mg kg−1), and the oxidative stress was stimulated under Mn contamination. But an appropriate concentration of K fertilizer (200 mg kg−1) was necessary for the formation of photosynthesis pigments, nonenzymatic antioxidants and antioxidant enzymes, metabolic processes, and nutrient uptake. Furthermore, when plants supplemented with a low level of K fertilization (200 mg kg−1), the catalase activity in C. oleifera leaves was enhanced to alleviate oxidative stress and protect the plant from Mn contamination. Our study demonstrated that 200 mg kg−1 of K fertilizer has the potential to further enhance the efficiency of Mn phytoremediation by C. oleifera.