Exogenous hydrogen sulphide alleviates copper stress impacts in Artemisia annua L.: Growth, antioxidant metabolism, glandular trichome development and artemisinin biosynthesis.

A supply of plant micronutrients (some of which are metals) is necessary to regulate many plant processes; their excess, however, can have detrimental consequences and can hamper plant growth, physiology and metabolism. Artemisia annua is an important crop plant used in the treatment of malaria. In this investigation, the physio-biochemical mechanisms involved in exogenous hydrogen sulphide-mediated (H2 S) alleviation of copper (Cu) stress in A. annua were assessed.. Two different levels of Cu (20, 40 mg·kg-1 ), one H2 S treatment (200 µm) and their combinations were introduced while one set of plants was retained as control. Results showed that the presence of excess Cu in the soil reduced growth and biomass, photosynthetic parameters, chlorophyll content and fluorescence, gas exchange parameters and induced antioxidant enzyme activity. Copper stress enhanced the production of thiobarbituric acid reactive substances (TBARS) and increased Cu content in both roots and shoots of affected plants. Exogenous application of H2 S restored the physio-biochemical characteristics of Cu-treated A. annua plants by reducing lipid peroxidation and enhancing the activity of antioxidant enzymes in Cu-stressed plants as compared with the controls. Hydrogen sulphide also reduced the Cu content in different plant parts, increased photosynthetic efficiency, trichome density, average area of trichomes and artemisinin content. Therefore, our results provide a comprehensive assessment of the defensive role of H2 S in Cu-stressed A. annua.

Draft Genome Sequence of the Plant Growth-Promoting Bacterium Pseudomonas pseudoalcaligenes KB-10.

Pseudomonas pseudoalcaligenes KB-10 can enhance salinity tolerance in coriander plants. We report a draft genome sequence of P. pseudoalcaligenes KB-10, comprising a 5,241,174-bp circular chromosome containing 4,921 genes, with a GC content of 62.97%.

Genetic heterogeneity in Pakistani microcephaly families revisited.

Autosomal recessive primary microcephaly (MCPH) is a rare and heterogeneous genetic disorder characterized by reduced head circumference, low cognitive prowess and, in general, architecturally normal brains. As many as 14 different loci have already been mapped. We recruited 35 MCPH families in Pakistan and could identify the genetic cause of the disease in 31 of them. Using homozygosity mapping complemented with whole-exome, gene panel or Sanger sequencing, we identified 12 novel mutations in 3 known MCPH-associated genes - 9 in ASPM, 2 in MCPH1 and 1 in CDK5RAP2. The 2 MCPH1 mutations were homozygous microdeletions of 164,250 and 577,594 bp, respectively, for which we were able to map the exact breakpoints. We also identified four known mutations - three in ASPM and one in WDR62. The latter was initially deemed to be a missense mutation but we demonstrate here that it affects splicing. As to ASPM, as many as 17 out of 27 MCPH5 families that we ascertained in our sample were found to carry the previously reported founder mutation p.Trp1326*. This study adds to the mutational spectra of four known MCPH-associated genes and updates our knowledge about the genetic heterogeneity of MCPH in the Pakistani population considering its ethnic diversity.

Regional permeability of coenzyme Q10 in isolated rat gastrointestinal tracts.

The objective of the study was to identify the region with the maximum permeability for low bioavailable coenzyme Q10 (CoQ) in the gastrointestinal tract. To evaluate the regional differences in permeability, male Sprague-Dawley rats, 250-300 g, were anesthetized and the gastrointestinal segments were isolated. Stomach, duodenum, jejunum, ileum and colon tissues were mounted on a Navicyte side-by-side diffusion apparatus. Radiolabeled CoQ (1 microM in DMEM, pH 7.4, 37 degrees C was added to the donor side and the samples withdrawn from the receiver compartment at predetermined time intervals were analyzed using a scintillation counter. Membrane integrity was monitored by 14C-mannitol permeability. The apical to basal permeability coefficients (Papp x 10(-6), cm/s) were 0.32 +/- 0.13, 3.14 +/- 0.89, 1.36 +/- 1.4, 0.83 +/- 0.40, and 1.59 +/- 0.13, for CoQ through rat stomach, duodenum, jejunum, ileum, and colon tissues respectively. The basolateral to apical permeability coefficients (Papp x 10(-6), cm/s) were 1.6 +/- 0.2, 2.2 +/- 1.2, 0.88 +/- 0.12, 1.6 +/- 0.42, and 1.9 +/- 0.41 respectively. Therefore the region of maximum CoQ permeability is duodenum followed by colon and ileum. Jejunum and stomach regions also have fairly high permeability. Therefore CoQ formulations should be made with an aim to target the duodenum to get maximum dosage effect.