Damage suffered by swamp morning glory (Ipomoea aquatica Forsk) exposed to vanadium (V)

Abstract

To elucidate the physiological and morphological responses generated by vanadium (V) in plants, hydroponic culture experiments were performed with swamp morning glory (Ipomoea aquatica Forsk) exposed to 0 mg L À1 to 2.50 mg L À1 pentavalent V [V(V)] in Hoagland nutrient solutions. The concentration of chlorophyll a, chlorophyll b, and carotene peaked at a V(V) concentration of 0.05 mg L À1 and gradually decreased at higher V(V) concentrations. Similarly, the plant biomass was stimulated at low levels of V(V) and was inhibited when V(V) concentrations exceeded 0.1 mg L À1 . Pentavalent V had negative effects on the uptake of phosphorus (P) by roots, shoots, and leaves. The biological absorption coefficients of V of the roots were higher than those of the aerial parts. Under low concentrations of V(V) exposure, the predominant species of V in the aerial parts was tetravalent V [V(IV)], whereas V(V) became more prevalent when concentrations of V(V) in the solution was higher than 0.50 mg L À1. In the roots, however, the concentrations of V(V) were always higher than those of the V(IV), except in the control group. Organelles in the V(V)-treated leaves were distorted, and the periplasmic space became wider. These results indicate V(V) has concentration-dependent effects on the physiological properties of swamp morning glory, whereas the plant has the ability to develop self-protective function to adapt to the toxicity of V(V). Environ Toxicol Chem 2016;35:695-701. # 2015 SETAC

Vanadium stimulates pepper plant growth and flowering, increases concentrations of amino acids, sugars and chlorophylls, and modifies nutrient concentrations

“…In general, there was a higher V concentration in leaves, followed by roots, and less so in stems (leaves>roots>stems). These results differ from those reported in pennyroyal (roots>stems>leaves) [ 12 ], soybean (roots>leaves) [ 38 ], common bean (roots>leaves) [ 39 ], swamp morning glory (roots>leaves>stems) [ 42 ], and basil (roots>leaves>stems) [ 55 ], where a higher concentration of V was reported in roots in comparison to leaves. These findings indicate that different plant species have different V absorption and mobilization capacities, as well as diverse response mechanisms to the same stimulus (V).…”

“…In stems, the concentrations of chlorophyll a , b , and total chlorophylls were higher in plants treated with 15 μM V; the concentrations of chlorophylls in the other treatments were lower or equal to the control ( Table 2 ). Some of these results are similar to those obtained in swamp morning glory with the application of 0.5 to 2.5 mg L -1 V in a liquid medium in hydroponics, since as the V concentrations increased, the concentrations of chlorophyll a and b decreased [ 42 ]. Likewise, in chickpea, the concentrations of chlorophyll a and b decreased as the levels increased (15 to 120 mg L -1 V) [ 41 ].…”

“…In chickpea ( Cicer arietinum ), the application of 60 to 120 mg L -1 V resulted in root growth inhibition because of the stress caused by the doses [ 41 ]. The application of V in swamp morning glory ( Ipomoea aquatic ) caused the roots to decrease their growth and turn thicker and darker [ 42 ], which could be due to an accumulation of toxic pentavalent vanadium (V +5 ). This is the most toxic form of V, being more reactive with a number of essential enzymes [ 43 ], and affecting reproductive processes [ 44 ].…”

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“…V 4+ is the predominant form in the soil, which is less mobile and toxic than the pentavalent (V 5+ ) form (Tian et al, 2015). Small amounts of V stimulate plant biomass production, whereas root and leaf growth inhibition and morphological changes have been reported with high levels of this element in Ipomoea aquatica (Chen et al, 2016 (Nalewajko et al, 1995). Este elemento forma parte de varias metaloenzimas como nitrogenasas (en Azotobacter chroococcum) y haloperoxidasas.…”

“…La forma predominante en el suelo es V 4+ , la cual es menos móvil y tóxica que la forma pentavalente (V 5+ ) (Tian et al, 2015). En plantas se ha reportado que pequeñas cantidades de V estimulan la producción de biomasa, mientras que niveles altos de este elemento inhiben el crecimiento y causan cambios morfológicos en hojas y raíz de Ipomoea aquatica (Chen et al, 2016 antocianinas (Schiavon et al, 2016).…”