Phytotoxicity of cobalt ions on the duckweed Lemna minor - Morphology, ion uptake, and starch accumulation.
Chemosphere
; 131: 149-56, 2015 Jul.
Article
en En
| MEDLINE
| ID: mdl-25840119
Cobalt (Co2+) inhibits vegetative growth of Lemna minor gradually from 1 µM to 100 µM. Fronds accumulated up to 21 mg Co2+ g(-1) dry weight at 10 µM external Co2+ indicating hyperaccumulation. Interestingly, accumulation of Co2+ did not decrease the iron (Fe) content in fronds, highlighting L. minor as a suitable system for studying effects of Co2+ undisturbed by Fe deficiency symptoms unlike most other plants. Digital image analysis revealed the size distribution of fronds after Co2+ treatment and also a reduction in pigmentation of newly formed daughter fronds unlike the mother fronds during the 7-day treatment. Neither chlorophyll nor photosystem II fluorescence changed significantly during the initial 4d, indicating effective photosynthesis. During the later phase of the 7-day treatment, however, chlorophyll content and photosynthetic efficiency decreased in the Co2+-treated daughter fronds, indicating that Co2+ inhibits the biosynthesis of chlorophyll rather than leading to the destruction of pre-existing pigment molecules. In addition, during the first 4d of Co2+ treatment starch accumulated in the fronds and led to the transition of chloroplasts to chloro-amyloplasts and amylo-chloroplasts, while starch levels strongly decreased thereafter.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Contaminantes Químicos del Agua
/
Cobalto
/
Araceae
Idioma:
En
Revista:
Chemosphere
Año:
2015
Tipo del documento:
Article
País de afiliación:
India
Pais de publicación:
Reino Unido