Arsenic Toxicity-Induced Physiological and Metabolic Changes in the Shoots of Pteris cretica and Spinacia oleracea

Arsenic is a ubiquitous toxic element that can be accumulated into plant parts. The present study investigated the response of Pteris cretica and Spinacia oleracea to As treatment through the analysis of selected physiological and metabolic parameters. Plants were grown in pots in As(V) spiked soil (20 and 100 mg/kg). Plants’ physiological condition was estimated through the determination of elements, gas-exchange parameters, chlorophyll fluorescence, water potential, photosynthetic pigments, and free amino acid content. The results confirmed differing As accumulation in plants, as well as in shoots and roots, which indicated that P. cretica is an As-hyperaccumulator and that S. oleracea is an As-root excluder. Variations in physiological and metabolic parameters were observed among As treatments. Overall, the results revealed a significant effect of 100 mg/kg As treatment on the analysed parameters. In both plants, this treatment affected growth, N, Mg, S, Mn, and Zn content, as well as net photosynthetic rate, chlorophyll fluorescence, and total free amino acid content. In conclusion, the results reflect the similarity between P. cretica and S. oleracea in some aspects of plants’ response to As treatment, while physiological and metabolic parameter changes related to As treatments indicate the higher sensitivity of S. oleracea.

A taxonomic study on Pteris L. (Pteridaceae) of Bangladesh

Bangladesh lies in Indian subcontinent, an area rich in Pteris species. However, so far there is no modern account on the species diversity of Pteris in Bangladesh. Based on a thorough study of literature and limited specimens available to us, we currently recognize 15 species of Pteris in Bangladesh. Among these species, P. giasii is currently known only from Bangladesh; P. longipinnula, which has not been collected since 1858, was recently rediscovered in Sylhet. Pteris cretica, P. pellucida, P. quadriaurita var. quadriaurita, and P. quadriaurita var. setigera are excluded for the fern flora of Bangladesh. To facilitate the recognition of species, a key to species and brief notes for each species are provided. Bangladesh J. Plant Taxon. 28(1): 131-140, 2021 (June)

The first register of the weed fern Pteris cretica var. laeta (Pteridaceae) in central Argentina

Pteris cretica L. var. laeta is recorded for the first time in the Comechingones biogeographic province in central Argentina. This is the first record of P. cretica in central Argentina, and P. cretica var. laeta for the country. Until now Pteris cretica has only been known to occur, in America, in North America (Florida), Central America and South America in Neotropical biomes from Peru, Chile, Brazil, Paraguay, Uruguay and northern Argentina as established in the Yungas biogeographic province, and as ruderal in Buenos Aires. An updated description is provided, along with pictures, differences with P. cretica var. cretica, and characteristic of the novel habitat of the species.

Free amino acid regulation in fronds and roots of two Pteris cretica L. ferns under arsenic stress

In the present study, free amino acid (AA) regulation in the arsenic (As) hyperaccumulating ferns was evaluated in a pot experiment to determine the relationship between As stress and the characteristic change in metabolism of AAs. The ferns Pteris cretica cv. Albo-lineata (Pc-Al) and cv. Parkerii (Pc-Pa) were exposed to As treatments at 0, 20, 100, and 250 mg As/kg for 90 days. Greater As content, as well as higher biomass production, were identified in Pc-Al compared with Pc-Pa. Ferns showed changes in the stress metabolism of free AA homeostasis. These results indicate a disturbance in nitrogen metabolism and depletion of pool assimilated carbon metabolism. In the fronds and roots, Pc-Pa accumulated higher amounts of free AAs than Pc-Al. The total free AA content, as well as the ratio of the main AA family pathway (glutamate family), were increased by the accumulation of toxic As in the ferns. Results suggest that Pc-Al tolerates higher As doses better due to changes in AA biosynthesis; however, at higher As doses, Pc-Pa upregulated AA biosynthesis due to As toxicity. The most abundant free AAs of ferns was glutamine, which was enhanced by As. Furthermore, the ratios of selected individual free AAs revealed a characteristic phenotype difference between ferns.

Kelimpahan Tumbuhan Paku (Pteridophyta) di Hutan Desa Tanglapui, Kecamatan Alor Timur, Kabupaten Alor

This study aims to determine the composition of species, diversity, and density of ferns in the Forest area of ​​Tanglapui Village, East Alor District, Alor Regency. To make observations and divide the study site into 4 stations, namely: stasium 1 east, stasium 2 south, stasium 3 north, and stasium 4 western parts, which contained nail plants (pteridophyta). At each station two observation plots were installed for sampling. Placement of the observation plot using purposive sampling by determining the starting point and installing a plot measuring 20 m long and 10 m wide. Every nail plant found at the study site was recorded. The data obtained is then processed to see the number of nail species found, the abundance of each fern, and the index of diversity of ferns using the Shannon-Wiener diversity formula. The results showed that 22 species of ferns were found, namely Diplazium esculentum, Cyathea contaminans, Lygodium venustum sw, Drynaria quercifolia, Platycerium bifurcatum, Microsorum punctatum, Equisetum debile, Pteris biaurita L, Pytirogramma calomelanos, Polypodium virginianum sp. cuneatum, Pteris cretica L, Davallia denticulate, Asplenium attenuatum, Psilotum nudum L, Marsilia polycarpa, Pteris vittata, Nephrolepis biserrata, Pyrrosia piloselloidesi L MG, Macrothelipteris torresiana. One of the ferns that dominates the tanglapui forest area is Cyathea contaminans with a total of 509 individuals with a density of 0.32 individuals / m2. The value of diversity in the lowland tanglapui forests is 0.77.