Topic
Bark
About: Bark is a research topic. Over the lifetime, 12004 publications have been published within this topic receiving 147931 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: The induction of a complex defense response in Norway spruce by methyl jasmonate application provides new avenues to evaluate the role of resin defenses for protection of conifers against destructive pests such as white pine weevils, bark beetles, and insect-associated tree pathogens.
Abstract: Norway spruce (Picea abies L. Karst) produces an oleoresin characterized by a diverse array of terpenoids, monoterpenoids, sesquiterpenoids, and diterpene resin acids that can protect conifers against potential herbivores and pathogens. Oleoresin accumulates constitutively in resin ducts in the cortex and phloem (bark) of Norway spruce stems. De novo formation of traumatic resin ducts (TDs) is observed in the developing secondary xylem (wood) after insect attack, fungal elicitation, and mechanical wounding. Here, we characterize the methyl jasmonate-induced formation of TDs in Norway spruce by microscopy, chemical analyses of resin composition, and assays of terpenoid biosynthetic enzymes. The response involves tissue-specific differentiation of TDs, terpenoid accumulation, and induction of enzyme activities of both prenyltransferases and terpene synthases in the developing xylem, a tissue that constitutively lacks axial resin ducts in spruce. The induction of a complex defense response in Norway spruce by methyl jasmonate application provides new avenues to evaluate the role of resin defenses for protection of conifers against destructive pests such as white pine weevils (Pissodes strobi), bark beetles (Coleoptera, Scolytidae), and insect-associated tree pathogens.
518 citations
TL;DR: Results from the in vitro antiamoebic activity of some Congolese plant extracts used as antidiarrhoeic in traditional medicine indicated that of 45 plant extracts tested, 35 (77.78%) exhibited an antiamoscular activity and 10 (22.22%) were inactive.
481 citations
TL;DR: Experimental studies in the Pacific Northwest and the southeast U.S.A., and in Norway, are drawn upon to show that tree resistance to attack may be closely related to the amount of current and stored photosynthate that is available for defense.
479 citations
TL;DR: To identify promising sources of antioxidants, some food and medicinal plants were studied for total phenolic contents and antioxidant activity and found that Leaves of Eucalyptusglobulus were a rich source of rutin and aerial parts of Centella asiatica for quercetin.
Abstract: To identify promising sources of antioxidants, some food and medicinal plants were studied for total phenolic contents and antioxidant activity. The leaves, bark and fruits of Terminalia arjuna, Terminalia bellerica, Terminalia chebula and Terminalia muelleri, the leaves and fruits of Phyllanthus emblica, and the seeds of Syzygium cumini were found to have high total phenolic contents (72.0–167.2 mg/g) and high antioxidant activity (69.6–90.6%). Leaves of Eucalyptusglobulus were a rich source of rutin, Moringa oleifera for kaempferol, aerial parts of Centella asiatica for quercetin, fruits of T. bellerica and T. chebula for gallic acid, and bark of T. arjuna, leaves and fruits of T. bellerica and bark, leaves and fruits of T. muelleri for ellagic acid.
385 citations
01 Jan 1989
347 citations