- J. Helder (1)
- L. Jeromel (1)
- G. Karssen (1)
- D. Mugniery (1)
- R. Mumm (1)
- P. Pelicon (1)
- P. Pongrac (1)
- P. Vavpetic (1)
- M.T. Villafort Carvalho (1)
Gomphrena claussenii, a novel metal-hypertolerant bioindicator species, sequesters cadmium, but not zinc, in vacuolar oxalate crystals
Villafort Carvalho, M.T. ; Pongrac, P. ; Mumm, R. ; Arkel, J. van; Aelst, A. van; Jeromel, L. ; Vavpetic, P. ; Pelicon, P. ; Aarts, M.G.M. - \ 2015
New Phytologist 208 (2015)3. - ISSN 0028-646X - p. 763 - 775.
Gomphrena claussenii is a recently described zinc (Zn)- and cadmium (Cd)-hypertolerant Amaranthaceae species displaying a metal bioindicator Zn/Cd accumulation response. We investigated the Zn and Cd distribution in stem and leaf tissues of G. claussenii at the cellular level, and determined metabolite profiles to investigate metabolite involvement in Zn and Cd sequestration. Gomphrena claussenii plants exposed to high Zn and Cd supply were analysed by scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) and micro-proton-induced X-ray emission (micro-PIXE). In addition, gas chromatography-time of flight-mass spectrometry (GC-TOF-MS) was used to determine metabolite profiles on high Zn and Cd exposure. Stem and leaf tissues of G. claussenii plants exposed to control and high Cd conditions showed the abundant presence of calcium oxalate (CaOx) crystals, but on high Zn exposure, their abundance was strongly reduced. Ca and Cd co-localized to the CaOx crystals in Cd-exposed plants. Citrate, malate and oxalate levels were all higher in shoot tissues of metal-exposed plants, with oxalate levels induced 2.6-fold on Zn exposure and 6.4-fold on Cd exposure. Sequestration of Cd in vacuolar CaOx crystals of G. claussenii is found to be a novel mechanism to deal with Cd accumulation and tolerance.
Description of Meloidoderita salina sp. n. (Nematoda, Sphaeronematidae) from a micro-tidal salt marsh at Mont-Saint-Michel Bay in France
Ashrafi, S. ; Mugniery, D. ; Heese, E. van; Aelst, A. van; Helder, J. ; Karssen, G. - \ 2012
ZooKeys 249 (2012). - ISSN 1313-2989 - p. 1 - 26.
atriplex-portulacoides l. - root-knot nematode - family heteroderidae - gene-sequences - ribosomal-rna - mixed models - tylenchida - tylenchoidea - criconematidae - tylenchulidae
Meloidoderita salina sp. n. is described and illustrated from the halophytic plant Atriplex portulacoides L. (sea purslane) growing in a micro-tidal salt marsh in the Mont-Saint-Michel Bay in France. This new species is the first member of Meloidoderita Poghossian, 1966 collected from a saline environment, and is characterized by the following features: sedentary mature femalesa small swollen body with a clear posterior protuberance; slightly dorsally curved stylet, 19.9 µm long, with posteriorly sloping knobs; neck region irregular in shape and twisted; well developed secretory-excretory (S–E) pore, with markedly sclerotized S-E duct running posteriorly; prominent uterus bordered by a thick hyaline wall and filled with eggs. The adult female transforms into a cystoid. Eggs are deposited in both egg-mass and cystoid. Cystoids of Meloidoderita salina sp. n. display a unique sub-cuticular hexagonal beaded pattern. Male without stylet, pharyngeal region degenerated, S-E duct prominent, deirids small, developed testis 97.5 µm long, spicules 18.4 µm long, cloacal opening ventrally protruded, small phasmids posterior to cloaca opening and situated at 5.9 (3.2–7.7) µm from tail end, and conical tail ending in a rounded terminus marked with one (rarely two) ventrally positioned mucro. Additionally, some young males of the new species were observed enveloped in the last J2 cuticle. Second-stage juvenile body 470 µm long, with a 16.4 µm long stylet, prominent rounded knobs set off from the shaft, hemizonid anterior and adjacent to S-E pore, small deirids located just above S-E pore level, genital primordium located at 68–77% of body length, phasmids small and located at about 19 µm from tail tip, and tail 38.7 µm long, tapering to finely pointed terminus with a finger-like projection. Phylogenetic analyses based on the nearly full length small subunit ribosomal DNA sequences of Meloidoderita salina sp. n. revealed a close relationships of the new species with Sphaeronema alni Turkina & Chizhov, 1986 and placed these two species sister to the rest of Criconematina.