Responses of Phragmites australis to copper stress: A combined analysis of plant morphology, physiology and proteomics

Abstract

Few relevant research attempts have been made to determine heavy metal resistance mechanisms of rhizomatous perennial plants. Thus, it is pertinent to investigate the physiological and biochemical changes in Phragmites australis under metal‐stressed conditions to facilitate the development of strategies to enhance copper (Cu) tolerance. We measured parameters related to plant growth and development, metal translocation and physiological responses of P. australis subjected to Cu stress. In addition, the differentially expressed proteins (DEP) were evaluated using the isobaric tag for relative and absolute quantification (iTRAQ) system. A large amount of copper accumulates in the roots of P.australis, but the growth parameters were not sensitive to Cu. However, the high concentration of Cu reduced the content of chlorophyll a and chlorophyll b, and the expression of important photosynthesis proteins PsbD, PsbO and PsaA were all down‐regulated, so photosynthesis was inhibited. In contrast, the content of ascorbic acid and proline both increased with the increase of copper stress. P.australis fixed a large amount of Cu in its roots, limiting the migration of Cu to other parts of the plant. Moreover, Cu stress can affect photosynthesis by inhibiting the activity of PSI, PSII and LHCII. In addition, P.australis synthesizes ascorbic acid through the D‐mannose/L‐galactose pathway, and synthesizes proline through the ornithine pathway. Ascorbic acid and proline can increase Cu tolerance and protect photosynthesis. These results provide a theoretical basis for understanding the tolerance and repair mechanisms of plants in response to heavy metal pollution.

Effects of abiotic stress on photosystem II proteins

“…Many other stresses can alter the structure and functionality of PSII proteins. For example, Wu et al (2021b) recorded the inhibition of the photosynthetic process in plants of Phragmites australis grown at high Cu concentrations related to a reduction in both Chl a and b contents but also a downregulation in the expression of PsbD, PsbO, and PsaA. Other trace elements such as Cd and Cr at toxic concentration induced negative effects on the structure of thylakoid complexes in Chlorella variabilis attributable to the generated oxidative stress (Zsiros et al 2020).…”

Development of a Site‐Specific Guideline Value for Copper and Aquatic Life in Tropical Freshwaters of Low Hardness

“…Other freshwater studies have reported the Cu sensitivity of cladocerans (Bossuyt & Janssen, 2005; De Schamphelaere et al, 2004; Hyne et al, 2005), algae (De Schamphelaere et al, 2003; Fawaz et al, 2018; Franklin et al, 2000; Macoustra et al, 2020; Wilde et al, 2006), and freshwater mussels (Augspurger et al, 2007; Gillis et al, 2008; Kleinhenz, 2019; March et al, 2007; Markich, 2017a). For plants, the influence of Cu on photosystems is well documented (Adams et al, 2016; Sameena & Puthur, 2021; Stauber & Florence, 1987; Wu et al, 2021), with Cu being a primary ingredient of algaecides used to control the growth of problem algae (Tsai, 2016). The adverse effect of Cu exposure on plant photosynthesis could also contribute to indirect toxicity for species that feed on alga (for the present study the cladoceran, hydra, and mussel).…”

Leucine Contributes to Copper Stress Tolerance in Peach (Prunus persica) Seedlings by Enhancing Photosynthesis and the Antioxidant Defense System

“…Wu et al found that Taxus chinensis var. chinensis synthesized a large amount of ASA, which was used to remove a large amount of H 2 O 2 accumulated in the root system to weaken high Cu toxicity [ 48 ]. In addition, plants can regulate the osmotic balance by increasing the contents of proline and other osmotic regulators, thus maintaining normal cell metabolism and improving plant stress resistance under heavy metal stress.…”