Work

Photosynthesis, photosystem II efficiency, amino acid metabolism and ion distribution in rice (Oryza sativa L.) in response to alkaline stress

Year: 2013

Type: article

Abstract: Alkalies are important agricultural contaminants complexly affecting plant metabolism. In this study, rice seedlings were subjected to alkaline stress (NaHCO3:Na2CO3 = 9:1; pH 8.9) for 30 days. The results showed that stress mightily reduced net photosynthetic rate (P N), but slightly decreased transpiration rate and stomatal conductance. This indicated that decline of P N might be a result of nonstomatal factors. Alkaline stress caused a large accumulation of Na+ in leaves up to toxic concentration, which possibly affected chloroplast ultrastructure and photosynthesis. We found that alkaline stress reduced chlorophyll fluorescence parameters, such as ratios of Fv'/Fm', Fv/Fm, photosystem (PS) II efficiency, and electron transport rates in rice plants, i.e. it influenced the efficiencies of photon capture and electron transport by PSII. This might be a main reason for the decrease of P N under such conditions. Deficiency of minerals could be another reason for the decline of P N. Alkaline stress lowered contents of N, K, Cu, Zn, P, and Fe in rice plants. In addition, the stress strongly affected metabolism of amino acids. This might be caused by imbalance in carbon metabolism as a result of photosynthesis reduction.

Source: Photosynthetica

DOI: 10.1007/s11099-014-0002-4

Authors: Z. H. Wu, C. W. Yang, M. Y. Yang

Institutions: Jilin Agricultural University, Northeast Normal University

Language: English

Topic: Plant Stress Responses and Tolerance

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: bronze

Funder: National Natural Science Foundation of China