today, biosphere pollution has accelerated strongly with start of industrial revolution by toxicity of heavy metals. one of existing pollution is soil pollution. unfortunately, soil pollution by metals is as intensive environmental stress for plant hence for human. plants, which are able to store heavy metals in their organs, can be used for phytoremediation of polluted soils and utilization of...

Molds, a subset of the fungi, are ubiquitous on our planet. Fungi are found in every ecological niche, and are necessary for the recycling of organic building blocks that allow plants and animals to live. Included in the group "fungi" are yeasts, molds and mildews, as well as large mushrooms, puffballs and bracket fungi that grow on dead trees. Fungi need external organic food sources and water...

The Athiorhodaceae are photosynthetic bacteria which grow anaerobically on media containing any one of a number of organic compounds, plus carbon dioxide and a source of growth factors, provided that the-cultures are illuminated. In contrast to the green plants, no oxygen is produced during photosynthesis. A number of strains will grow in the dark provided that oxygen is present. Themost genera...

Circadian clocks are believed to confer an advantage to plants, but the nature of that advantage has been unknown. We show that a substantial photosynthetic advantage is conferred by correct matching of the circadian clock period with that of the external light-dark cycle. In wild type and in long- and short-circadian period mutants of Arabidopsis thaliana, plants with a clock period matched to...

This review provides a good overview of biological nitrogen fixation in the growth of leguminous plants, particularly relating to fertilizer needs for crops. In addition to plants that form nodules that host nitrogen-fixing bacteria, other bacteria form different associations with plants, and this is currently under intense study to determine if there is significant nitrogen transfer to the pla...

In this review, plant-insect interaction is discussed as a dynamic system, subjected to continual variation and change. Plants developed different mechanisms to reduce insect attack, including specific responses that activate different metabolic pathways which considerably alter their chemical and physical aspects. On the other hand, insects developed several strategies to overcome plant defens...

Smirnovia iranica (Sabeti) synonym: Smirnovia turkestana (Bunge) is a deciduous perennial bushy species of the Fabaceae (Papilionaceae) family. The species grow on sand dunes of desert areas, having a deep vertical root and very long horizontal or lateral roots. They have an important role in natural vegetation of desert and sand dune stabilization. Limited growing areas, grazing due to good pa...

Asphaltenes are the n-pentane or n-heptane insoluble fractions of crude oil that remain in solution under reservoir temperature and pressure conditions. They are destabilized and start to precipitate when the pressure, temperature and/or composition changes occur during primary production. The precipitated asphaltene particles will then grow in size and may start to deposit onto the product...