Contribution of N : P ratio and endogenous phytohormones during development of phosphorus toxicity in Brassica campestris spp. parachinensis

Abstract

Agricultural practices may lead to excessive phosphorus (P) accumulation in soil. The effects of excessive P on Chinese flowering cabbage (Brassica campestris spp. parachinensis) were investigated by exposing plants for 4 weeks in solution containing 1, 2, 3, 5, and 7 mM NaH2PO4. Phosphorus concentrations [P] greater than 3 mM produced significantly stunted growth, together with reduced appearance quality due to overaccumulation of anthocyanin in the epidermis of flower stalk. Nitrate concentrations in the flower stalk decreased with increasing solution [P]. Nitrogen (N) concentrations in the roots and potassium (K) concentrations in the leaves, stems, and roots all decreased at [P] higher than 3 mM. Increasing P supply caused great enhancement of root and stem [P], but decreased total plant and root N : P ratios. A positive linear relationship between solution [P] and anthocyanin concentration and a negative linear relationship between root N : P ratio and anthocyanin concentration were also observed. In addition, 3 to 7 mM P caused decreased levels of indole‐3‐acetic acid (IAA) and gibberellin (GA3) in the leaves, but promoted ethylene production. The average gibberellin concentration was generally correlated with the plant's relative growth rates. Ethylene was negatively correlated with plant growth parameters except for the last day of the experiment. In conclusion, N : P ratio and endogenous phytohormones may be involved in the development of P toxicity in Chinese flowering cabbage plants.

Effects of Iron Deficiency Stress on Plant Growth and Quality in Flowering Chinese Cabbage and Its Adaptive Response

“…The lack of Fe nutrition gradually becomes the key factor limiting the yield of flowering Chinese cabbage due to the continuous increase in multiple cropping index and the increasing degree of soil alkalization. Our previous study indicated that mineral nutrition had clear effects on the growth, yield, quality, and disease resistance of flowering Chinese cabbage [11][12][13][14]. However, the effects of Fe deficiency on the growth and development of flowering Chinese cabbage and its related physiological characteristics are still lacking an investigation.…”

Effects of Iron Deficiency Stress on Plant Growth and Quality in Flowering Chinese Cabbage and Its Adaptive Response

“…The lack of Fe nutrition gradually becomes the key factor limiting the yield of owering Chinese cabbage due to the continuous increase of multiple cropping index and the higher and higher degree of soil alkalization. Our previous study indicated that mineral nutrition has obvious effects on the growth, yield, quality, and disease resistance of owering Chinese cabbage (Chai et al 2013;Yang et al 2000Yang et al , 2004Yang et al , 2012.…”