miRNAs: Major modulators for crop growth and development under abiotic stresses

Cumulatively, biotic and abiotic stresses of various magnitudes can decrease the production of crops by 70%. miRNAs have emerged as a genetic tool with enormous potential that can be exploited to understand stress tolerance at the molecular level and eventually regulate stress in crops. Plant miRNA targets frequently fit into diverse families of TFs that control the expression of genes related to a certain trait. As key machinery in gene regulatory networks, it is agreed that a broad understanding of miRNAs will greatly increase our understanding of plant responses to environmental stresses. miRNA-led stress regulatory networks are being considered as novel tools for the development of abiotic stress tolerance in crops. At this time, we need to expand our knowledge about the modulatory role of miRNAs during environmental fluctuations. It has become exceedingly clear that with increased understanding of the role of miRNAs during stress, the techniques for using miRNA-mediated gene regulation to enhance plant stress tolerance will become more effective and reliable. In this review we present: (1) miRNAs as a potential avenue for the modulation of abiotic stresses, and (2) summarize the research progress regarding plant responses to stress. Current progress is explained through discussion of the identification and validation of several miRNAs that enhance crop tolerance of salinity, drought, etc., while missing links on different aspects of miRNAs related to abiotic stress tolerance are noted.     

Expression studies of stress responsive genes in cotton Gossypium hirsutum L.

Molecular Biology Reports - Cotton is the world’s richest source of natural fiber. Meanwhile cotton plant is top ranked stress sensitive plant thereby affecting its yield and fiber quality....     

Bluejay 1.0: genome browsing and comparison with rich customization provision and dynamic resource linking

Background  

The Bluejay genome browser has been developed over several years to address the challenges posed by the ever increasing number of data types as well as the increasing volume of data in genome research. Beginning with a browser capable of rendering views of XML-based genomic information and providing scalable vector graphics output, we have now completed version 1.0 of the system with many additional features. Our development efforts were guided by our observation that biologists who use both gene expression profiling and comparative genomics gain functional insights above and beyond those provided by traditional per-gene analyses.     

Natural enemies ofChenopodium spp. in Pakistan with notes onTrioza Chenopodii [Hem.: Psyllidae], a promising biocontrol agent

Investigations on the natural enemies ofChenopodium spp. in Pakistan showed that 40 insects and a fungus were associated with this weed. Of these, 3 insects,Trioza chenopodii Reuter,Gasteroclisus auriculatus Sahlb.Hayhustria? atriplicis (L.) and a fungusPhysoderma pulposum have some potential as beneficial control agents.T. chenopodii was the most effective destroyer of the weed. It developed 5 generations per year and was restricted to the generaChenopodium, Atriplex andHalimione.     

Processing liquid-based gynecologic specimens: comparison of the available techniques.

OBJECTIVE: To develop a cytopreparation protocol suitable for satisfactory processing by the AutoCyte PREP System with the gynecologic specimens collected in PreservCyt fluid for the ThinPrep machine. STUDY DESIGN: The residue of a number of gynecologic specimens collected in PreservCyt and processed by ThinPrep were processed by AutoCyte PREP. Some modifications were made in the cytopreparatory protocol in order to obtain satisfactory specimens. RESULTS: The ThinPrep and AutoCyte PREP specimens were examined independently. The results were comparable, with a high degree of concordance between the two techniques. CONCLUSION: Gynecologic specimens collected in PreservCyt and following the ThinPrep specimen collection protocol can be processed using the AutoCyte PREP System. Minor protocol modifications provided comparable diagnostic material. Additional studies are needed to explore the feasibility of this approach and fulfill the various U.S. regulatory agency requirements for the liquid-based Pap test.     

Biological control ofCuscuta spp. III. Phenology,biology and host-specificity ofHerpystis cuscutae Bradley [Lep., Tortricidae]

Life history and status ofHerpystis cuscutae as biological control agent have been investigated. Of the tenCuscuta spp. in Pakistan it infested onlyC. reflexa on six host plants of whichAdhatoda vasica andDodonaea viscosa were the most preferred. Variations in its period of activity in different areas were attributed to the differences in the fruiting periods of its host. It was found to have a tolerance for extremes of climates, was multivoltine, could complete development on some convolvules, legumes and umbellifers among the plants of 28 families tested and was apparently free from natural enemies.     

Ontogenesis of the murine hepatic extracellular matrix: an immunohistochemical study

To define the role of the extracellular matrix (ECM) in hepatogenesis, we examined the temporal and spatial deposition of fibronectin, laminin and collagen types I and IV in 12.5-21.5 day fetal and 1, 7 and 14 day postnatal rat livers. In early fetal liver, discontinuous deposits of the four ECM components studied were present in the perisinusoidal space, with laminin being the most prevalent. All basement membrane zones contained collagen type IV and laminin, including those of the capsule (mesothelial), portal vein radicles and bile ductules. Fibronectin had a distribution similar to that of collagen type IV early in gestation. However, at later gestational dates, fibronectin distribution in the portal triads approached that of collagen type I, being present in the interstitial connective tissues; whereas, collagen type IV and laminin were restricted to vascular and biliary basement membrane zones in those regions. The cytoplasm of some sinusoidal lining cells and hepatocytes reacted with antibodies to extracellular matrix components. By electron microscopy the immunoreactive material was localized in the endoplasmic reticulum, indicating the ability of these cells to synthesize these ECM proteins. Biliary ductular cells had prominent intracytoplasmic staining for laminin and collagen type IV from day 19.5 gestation until 7 days of postnatal life, but lacked demonstrable fibronectin or collagen type I. These results demonstrate that by 12.5 days of gestation the rat liver anlage has deposited a complex extracellular matrix in the perisinusoidal space. The prevalence of laminin in the developing hepatic lobules suggests a possible role for this glycoprotein in hepatic morphogenesis. In view of the intimate association of the hepatic lobular extracellular matrix with the developing vasculature, we hypothesize that laminin provides a scaffold of the developing liver, but once the ontogenesis is complete, intrahepatic perisinusoidal laminin expression is suppressed.