The Ameliorative Effect of Coumarin on Copper Toxicity in : Insights from Growth, Nutrient Uptake, Oxidative Damage, and Photosynthetic Performance.

Excessive copper (Cu) has become a common physiological disorder restricting the sustainable production of citrus. Coumarin (COU) is a hydroxycinnamic acid that can protect plants from heavy metal toxicity. No data to date are available on the ameliorative effect of COU on plant Cu toxicity.

The adaptation of root cell wall pectin to copper toxicity in two citrus species differing in copper tolerance: remodeling and responding.

Citrus species are prone to suffer from copper (Cu) toxicity because of improper application of Cu-based agrochemicals. Copper immobilization mediated by pectin methylesterase (PME) in the root cell wall (CW) is effective for Cu detoxification. However, the underlying mechanisms of the structural modification and stress responses of citrus root CW pectin to Cu toxicity have been less discussed.

Physiological and Ultrastructural Responses to Excessive-Copper-Induced Toxicity in Two Differentially Copper Tolerant Citrus Species.

Over-applied copper (Cu)-based agrochemicals are toxic to citrus trees. However, less information is available discussing the ultrastructural alterations in Cu-stressed citrus species. In the present study, seedlings of and that differed in Cu-tolerance were sandy-cultured with nutrient solution containing 0.

High pH Alleviated Sweet Orange () Copper Toxicity by Enhancing the Capacity to Maintain a Balance between Formation and Removal of Reactive Oxygen Species and Methylglyoxal in Leaves and Roots.

The contribution of reactive oxygen species (ROS) and methylglyoxal (MG) formation and removal in high-pH-mediated alleviation of plant copper (Cu)-toxicity remains to be elucidated. Seedlings of sweet orange () were treated with 0.5 (non-Cu-toxicity) or 300 (Cu-toxicity) μM CuCl × pH 4.

Photosynthetic Characteristics and Chloroplast Ultrastructure Responses of Citrus Leaves to Copper Toxicity Induced by Bordeaux Mixture in Greenhouse.

Bordeaux mixture (Bm) is a copper (Cu)-based pesticide that has been widely used for controlling citrus scab and citrus canker. However, frequent spraying of Bm is toxic to citrus. To our knowledge, few studies are available that discuss how the photosynthetic characteristics and chloroplast ultrastructure of citrus leaves are affected by Cu toxicity induced by excessive Bm.

The aluminum distribution and translocation in two citrus species differing in aluminum tolerance.

Background: Many citrus orchards of south China suffer from soil acidification, which induces aluminum (Al) toxicity. The Al-immobilization in vivo is crucial for Al detoxification. However, the distribution and translocation of excess Al in citrus species are not well understood.

Adaptive Responses of Leaves to Copper Toxicity Revealed by RNA-Seq and Physiology.

Copper (Cu)-toxic effects on growth and Cu uptake, as well as gene expression and physiological parameters in leaves were investigated. Using RNA-Seq, 715 upregulated and 573 downregulated genes were identified in leaves of seedlings exposed to Cu-toxicity (LCGSEC). Cu-toxicity altered the expression of 52 genes related to cell wall metabolism, thus impairing cell wall metabolism and lowering leaf growth.

Excess Copper-Induced Alterations of Protein Profiles and Related Physiological Parameters in Citrus Leaves.

This present study examined excess copper (Cu) effects on seedling growth, leaf Cu concentration, gas exchange, and protein profiles identified by a two-dimensional electrophoresis (2-DE) based mass spectrometry (MS) approach after and seedlings were treated for six months with 0.5 (control), 200, 300, or 400 μM CuCl. Forty-one and 37 differentially abundant protein (DAP) spots were identified in Cu-treated and leaves, respectively, including some novel DAPs that were not reported in leaves and/or roots.

Analysis of Interacting Proteins of Aluminum Toxicity Response Factor ALS3 and CAD in .

Aluminum (Al) treatment significantly decreased the dry weight (DW) of stem, shoot and whole plant of both and , but did not change that of root. Al significantly decreased leaf DW of , increased the ratio of root to shoot and the lignin content in roots of both species. The higher content of Al in leaves and stems and lignin in roots of than that of might be due to the over-expression of Al sensitive 3 (ALS3) and cinnamyl alcohol deaminase (CAD) in roots of , respectively.

Excess copper effects on growth, uptake of water and nutrients, carbohydrates, and PSII photochemistry revealed by OJIP transients in Citrus seedlings.

Seedlings of 'Shatian pummelo' (Citrus grandis) and 'Xuegan' (Citrus sinensis) were supplied daily with nutrient solution at a concentration of 0.5 (control), 100, 200, 300, 400, or 500 μM CuCl for 6 months. Thereafter, seedling growth; leaf, root, and stem levels of nutrients; leaf gas exchange; levels of pigments; chlorophyll a fluorescence (OJIP) transients and related parameters; leaf and root relative water content; levels of nonstructural carbohydrates; HO production rate; and electrolyte leakage were comprehensively examined (a) to test the hypothesis that Cu directly damages root growth and function, thus impairing water and nutrient uptake and hence inhibiting shoot growth; (b) to establish whether the Cu-induced preferential accumulation of Cu in the roots is involved in Cu tolerance of Citrus; and (c) to elucidate the possible causes for the Cu-induced decrease in photosynthesis.