Optimization of potassium for proper growth and physiological response of Houttuynia cordata Thunb.

Abstract

a b s t r a c tHouttuynia cordata Thunb. is an edible herb with a variety of pharmacological activities, but only limited information is available about its response towards potassium supplementation. Sterile plantlets were cultured in media with different potassium levels, and parameters related to growth, foliar potassium, water and chlorophyll contents, photosynthesis, transpiration, H 2 O 2 contents and antioxidative enzyme activities were determined after a month. Results showed that 1.28 mM potassium was the optimum for H. cordata as highest values of dry weight, shoot height, root length and number were obtained at this concentration. The optimum potassium concentration resulted in the maximum net photosynthetic rate which could be associated with the highest chlorophyll content rather than limited stomatal conductance. The supply of surplus potassium resulted in higher content of foliar potassium, but negatively correlated with the biomass. Both potassium starvation (0 mM) and high potassium (>1.28 mM) could lead to water loss through high transpiration rate and low water absorption, respectively, and resulted in H 2 O 2 accumulation and increased activities of catalase and peroxidase, which suggested induction of oxidative stress. Moreover, H. cordata showed the minimum of H 2 O 2 content and the maximum of superoxide dismutase activity on 1.28 mM potassium, implying its role in inducing tolerance against oxidative stress.

Effects of Ascophyllum nodosum seaweed extracts on lettuce growth, physiology and fresh‐cut salad storage under potassium deficiency

“…In previous reports, antioxidant enzyme (SOD, CAT, peroxidase) activity was increased in K‐deficient bean ( Phaseolus vulgaris L.) leaves and chameleon plant ( Houttuynia cordata Thunb. ), being in accordance with the increased SOD activity found in K125 compared with K375 treatment (Fig. C).…”

Optimization of potassium fertilization/nutrition for growth, physiological development, essential oil composition and antioxidant activity of Lavandula angustifolia Mill

“…Shin et al (2005) (Hafsi et al, 2014). Although the increased K levels resulted in higher contents of leaf potassium as compared to lower K levels, the higher leaf potassium did not improve the plant biomass, being in accordance with previous studies (Xu et al, 2011). Potassium interacts with almost all essential elements.…”

“…H 2 O 2 can be removed through the ascorbate-glutathione cycle AsA-GSH whereas the APX and the SOD are the key enzymes in this cycle (Pasternak et al, 2005). Antioxidant enzymes (SOD, CAT, peroxidase) activity increased in K-deficient bean leaves (Cakmak, 2005) and Houttuynia cordata (Xu et al, 2011). Results of the present study showed that 325 mg L -1 of K application decreased the MDA content compared with the 275 mg L -1 of K, maybe by elimination of free radicals (Sharma et al, 2012).…”

Optimisation of Potassium Chloride Nutrition for Proper Growth, Physiological Development and Bioactive Component Production in Prunella vulgaris L

“…Potassium starvation and high potassium conditions cause oxidative stress due to the formation of reactive oxygen species (ROS; e.g., O 2 •− and H 2 O 2 ) [43], [59], [60], [61]. To protect themselves against the injurious effects of ROS, plants have evolved complex antioxidant system which includes enzymatic antioxidants and non-enzymatic antioxidants [62].…”