Article Evaluation

Pinaceae

I read the Wikipedia article on Pinaceae, a family of conifers. Overall, the information in this article is informative and stays on topic. However, there are a few problems with it. For example, one of the subfamilies, Abietoide, does not have a Wikipedia page, which is unfortunate. There is a lot of information on the cones that come from this family of conifers, however, there is little to no citations within the text. There are very few references (only 4) in the Reference list; so this article may need more references in order to be a verified article. There is also information on each of the subfamilies within Pinaceae, as well as links for each subfamily. However, when clicking on each link for the subfamilies, the information that is displayed on the Pinaceae page is not included and there aren't any in text citations either, which is problematic. I also think that information on the life cycle of this species is necessary. We have talked about the life cycle of pine trees in class, so adding this information should not be too difficult, as it is a well-known life cycle. I also think that a section on identifying features of this family would be helpful as well in order to make identification easier for the average citizen.

There is also no conversation on the Talk page for this article, but it is included in the WikiProject Plants page. This article is rated as a Start-Class on the project's quality scale and rated as high-importance on the project's importance scale.

Possible Topics

Pinaceae

I could add to the Wikipedia page on Pinaceae and verify references as well as add in more references to the reference page. In text citations also need to be added, which I should be able to do, as well as potentially add information on the life cycle of the family.

Taproot

I could help improve the Wikipedia page on Taproot because there is not a lot of in-text citations as well as references in the Reference List of the article. I can also fact check the information that is already included in this article and add the appropriate in-text citations.

Amaranthus hybridus

This Wikipedia page on Amaranthus hybridus lacks in-text citations as well as references in the Reference section of the article. There is also not a lot of information on the plant species in most of the sections which I can also attempt to improve.

Pinaceae Bibliography

*going to focus on the defense mechanisms of the pine family and background information (including life cycle)*

Eckert, A. J. and B. D. Hall. 2006. Phylogeny, historical biogeography, and patterns of diversification for Pinus (Pinaceae): phylogenetic tests of fossil-based hypotheses. Molecular Phylogenetics and Evolution 40:166-182.

Cherubini, P., G. Fontanta, D. Rigling, M. Dobbertin, P. Brang, and J. L. Innes. 2002. Tree-life history prior to death: two fungal root pathogens affect tree-ring growth differently. Journal of Ecology 90:839-850.

Lewinsohn, E., M. Gijzen, and R. Croteau. 1990. Defense mechanisms of conifers. Plant Physiology 96:44-49.

Franceschi, V. R., P. Krokene, T. Krekling, and E. Christiansen. 2000. Phloem parenchyma cells are involved in local and distance defense response to fungal inoculation or bark-beetle attack in Norway spruce (Pinaceae). American Journal of Botany 87:314-326.

Franceschi, V. R., P. Krokene, E. Christiansen, and T. Krekling. 2005. Anatomical and chemical defenses of conifer bark against bark beetles and other pests. The New Phytologist 167:353-375.

Gruwez, R., O. Leroux, P. De Frenne, W. Tack, R. Viane, and K. Verheyen. 2012. Critical phases in the seed development of common juniper (Juniperus communis). Plant Biology 15:210-219.

Harcombe, P. A. 1987. Tree life tables. Bioscience 37: 557-568.

Just, T. 1948. Gymnosperms and the origin of angiosperms. Botanical Gazette 110:91-103.

Walters, D. R., D. J. Kell. 1975. Vascular plant taxonomy. Kendall/ Hunt Publishing Company, Dubuque, Iowa.

Zulak, K. G. and J. Bohlmann. 2010. Terpenoid biosynthesis and specialized vascular cells of conifer defense. Journal of Integrative Biology 52:86-97.

Pinaceae Outline

Background Information (add to already existing section)

• The temperate areas of the Northern Hemisphere has 110-120 species of Pinus scattered throughout the region and several considerable differences have been identified within the genus. ^[1]

Life Cycle

• 3 seed phases: ^[2]
  • gamete development
  • fertilization and early embryo development
  • late-embryo development
• whole life cycle ^[3]

Defense Mechanisms (new section)

• External stresses on plants have the ability to change the structure and composition of forest ecosystems. Diseases are very prevalent and cause tree death. ^[4] Trees need to adapt or evolved defenses against these stresses.
• Conifers have developed a large amount of different mechanical and chemical defenses to deal with herbivore and pathogen antagonism ^[5]
• defense combination of constitutive mechanical and chemical defenses with the ability to up-regulate further defenses. ^[6]
• bark of conifers
  • can contribute to a complex defensive boundary against potential. ^[7]
  • Secondary compounds compounds used for defense: secondary resins, synthesis of new phenolics, traumatic resin duct formation, and initiation of wound periderm. ^[7]
  • This boundary contains static and constitutive defenses. ^[7]
    • Constitutive defenses
      • permanently expressed and are a part of the first line of resistance. ^[8]
      • give immediate defense against invasion of the bark but organisms can adapt to these structures to get past this defense. ^[7]
      • phenolics/ polyphenols
        • stored in vacuoles of polyphenolic parenchyma cells (PP cells) in secondary phloem ^[9]
    • Inducible responses ^[7]
      • need to be activated in response biotic challenges or damage. ^[8]
      • resin
        • complicated combo of volatile mono- (C₁₀) and sesquiterpenes (C₁₅) and nonvolatile diterpene resin acids (C₂₀). ^{[5] [10]}
        • synthesized and stored in specialized secretory areas such as resin ducts, resin blisters, and resin cavities. ^[10]
          • short term ^[10]
          • resin induction and resin synthesis represents widespread defense mechanism in Pinaceae. Could have developed evolutionary adaptation in retaliation against bark-beetle attack ^[10]
        • can flush out or trap antagonists ^[9]
        • has toxic and inhibitory effects on insects and pathogens ^[11]
        • involved in wound sealing ^[9]
          • Oleoresin
            • a valuable part of the conifer defense mechanism against herbivores and pathogens. It is found in secretory tissues of the tree stems, roots, and leaves. Oleoresin is also crucial for conifer classification. ^[11]
• methyl jasmonate treatment
  • in stem ^[12]
  • induced resin production ^[12]

Defense draft for peer review

**grammar errors fixed** 4/10/18

***tried to find more on other defenses and I could only find articles on resins*** 4/17/18

Defense Mechanisms

External stresses on plants have the ability to change the structure and composition of forest ecosystems. Common external stress that Pinaceae experience are herbivore and pathogen attack which often leads to tree death. ^[4] In order to combat these stresses, trees need to adapt or evolve defenses against these stresses. Pinaceae have evolved a myriad of mechanical and chemical defenses, or a combination of the two, in order to protect themselves against antagonists. ^[5] Pinaceae have the ability to up-regulate a combination of constitutive mechanical and chemical strategies to further their defenses. ^[6]

Pinaceae defenses are prevalent in the bark of the trees. This part of the tree contributes a complex defensive boundary against external antagonists. ^[7] Constitutive and induced defenses are both found in the bark. ^{[7] [12] [13]}

Constitutive defenses

Constitutive defenses are typically the first line of defenses used against antagonists and can include sclerified cells, lignified periderm cells, and secondary compounds such as phenolics and resins. ^{[8] [7] [12]} Constitutive defenses are always expressed and offer immediate protection from invaders but could also be defeated by antagonists that have evolved adaptations to these defense mechanisms. ^{[8] [7]} One of the common secondary compounds used by Pinaceae are phenolics or polyphenols. These secondary compounds are preserved in vacuoles of polyphenolic parenchyma cells (PP) in the secondary phloem. ^{[9] [13]}

Induced Defenses

Induced defense responses need to be activated by certain cues, such as herbivore damage or other biotic signals. ^[8]

A common induced defense mechanism used by Pinaceae is resins. ^[10] Resins are also one of the primary defenses used against attack. ^[5] Resins are short term defenses that are composed of a complex combination of volatile mono- (C₁₀) and sesquiterpenes (C₁₅) and nonvolatile diterpene resin acids (C₂₀). ^{[5] [10]} They are produced and stored in specialized secretory areas known as resin ducts, resin blisters, or resin cavities. ^[10] Resins have the ability to wash away, trap, fend off antagonists, and are also involved in wound sealing. ^[9] They are are an effective defense mechanism because they have toxic and inhibitory effects on invaders, such as insects or pathogens. ^[11] Resins could have developed as an evolutionary defense against bark beetle attacks. ^[10] One well researched resin present in Pinaceae is oleoresin. Oleoresin had been found to be a valuable part of the conifer defense mechanism against biotic attacks. ^[11] They are found in secretory tissues in tree stems, roots, and leaves. ^[11] Oleoresin is also needed in order to classify conifers. ^[11]

Active research: methyl jasmonate (MJ)

The topic of defense mechanisms within family Pinaceae is a very active area of study with numerous studies being conducted. Many of these studies use methyl jasmonate (MJ) as an antagonist. ^{[12] [13] [14]} Methyl jasmonate is known to be able to induce defense responses in the stems of multiple Pinaceae species. ^{[12] [14]} It has been found that MJ stimulated the activation of PP cells and formation of xylem traumatic resin ducts (TD). These are structures that are involved in the release of phenolics and resins, both forms of defense mechanism. ^{[12] [13]}

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