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Extracellular polymeric substances (EPS) are the giant polymers composed of polysaccharides, proteins, nucleic and humic acid with remarkable applications. This study was aimed to evaluate the binding efficacies of two EPS extracted from cyanobacterial strains (Microsystis aeruginosa and Microsystis ichthyoblabe) with four heavy metal ions (lead, cadmium, copper, and zinc) using excitation-emission matrix (EEM) spectroscopy with the main focus on the fluorescence properties of protein present in each EPS. Characterization of EPS showed that they were composed of > 90% of organic contents with higher carbohydrates (59.54 and 60.72%) than proteins (26.49% and 30.2%) and lower humic acid contents (8.29% and 6.96%). The amino acids profile revealed tryptophan at maximum (6.28% in EPS-A and 4.26% in EPS-I) followed by tyrosine (5.05% in EPS-A and 3.47% in EPS-I), glutamic acid (4.14% in EPS-A and 2.74% in EPS-I), leucine (3.92% in EPS-A and 2.82% in EPS-I) and phenylalanine (3.14% in EPS-A and 1.97% in EPS-I). The percentages of amino acids recorded were higher in EPS-A than EPS-I. A fluorescence peak at 280/350 nm (Ex/Em) was identified in the fluorescence spectrum for each EPS using EEM spectroscopy. Quenching experiments showed gradual decrease in EPS fluorescence intensity with increased metal concentration due to EPS-metal association. The Stern–Volmer plot displayed static quenching mechanism of metals in deactivating EPS fluorophores. Pb(II) and Cd(II) displayed superior quenching at 50 mg/L whereas Zn(II) and Cu(II) indicated lower quenching at 100 mg/L. The binding potencies of EPS from cyanobacteria with metal ions is a potential green biotechnological approach for toxic metals remediation from aqueous medium. [ABSTRACT FROM AUTHOR]

Artemisia chamaemelifolia Vill. is a perennial herb from the genus Artemisia of the Asteraceae family. This plant is mostly distributed in Armenia, Russia, Georgia and the Eurasian mountains including Cantabrian chain, Spanish Sierra Nevada, the Alps (France and Italy), Azerbaijan, Pyrenees, the Balkan range (Bulgaria), northeast and east Anatolia (Turkey) and the mountain regions of Northern Iran. In continuation of our preceding papers on Northeastern Pakistani Artemisia, here we report the local occurrence of A. chamaemelifolia from Pakistan by critically analyzing its geographical distribution. To date, we have found the species in 4 major areas of Ghizer, Gilgit, Hunza-Nagar and Skardu districts of Gilgit-Baltistan region of Pakistan. Phylogenetic analysis with maximum likelihood approach using the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA showed resemblance of northeastern Pakistani A. chamaemelifolia with other Artemisia species reported from other parts of the world. This species has been listed as critically endangered in the national IUCN red list of many countries. It is recommended that A. chamaemelifolia plant should be included in the rare plant species list in the flora of Pakistan. It will ensure conservation approaches to circumvent its extinction from the country. [ABSTRACT FROM AUTHOR]

Salt stress is the important abiotic stresses depressing gainful crop production. This study assessed rice morphologically with DREB1A gene under inducible and constitutive promoters against salinity. Non transgenic and transgenic rice plants with two transgenic events (35S-DREB1A and LIP-9 DREB1A) were assessed under salt stress and controlled conditions. The germinated healthy and uniform seedlings of rice plants with two events were transplanted in pots (25 × 35 cm) filled with soil and irrigated with tap water. Nitrogen and Phosphorus fertilizers were applied at the ratio of 100 kg/ha and 50 kg/ha respectively in the form of DAP and murate of potash. Sodium chloride (NaCl) in different increments was added in medium till stress level of 12 ± 2 dS m−1NaCl was obtained and maintained till maturity. The control medium without added salts, with an ECw of 0.50-0.90 dSm−1 was also maintained. After maturity, harvesting was done and yield components data were recorded. Results showed significant decrease in all morphological parameters of transgenic rice. Among the tested rice plants, lowest reduction in whole plant weight was observed in Lip-9 DREB1A while the most sensitive were 35S-DREB1A and wild type. Plants with Lip9-DREB1A and 35S-DREB1A gene exhibited increased fertility than in wild type but eventually Lip9-DREB1A plants with Lip-9 promoter produced higher yield than 35S-DREB1A plants under salt stress. It indicated that Lip9 promoter helped in steady increase in transcription under salinity giving capability to produce more seeds that increases final yield. Conventional PCR system confirmed the presence of transgene (DREB1A) in all transgenic rice plants that give tolerance against salt stress. STIs values showed salt tolerance among rice plants which nominates Lip9-DREB1A to be the more salt tolerant transgenic rice line than wild type and 35S-DREB1A. Exploitation of inducible promoter (Lip9) in plants for abiotic stress tolerance may be more helpful than constitutive promoters (35S). [ABSTRACT FROM AUTHOR]