User:AustinRyder117/sandbox

Adding to: Plant Molecular Biology of Trichomes, under the main trichome Wikipedia page.

Will focus on the genetic and biochemical interactions between the trichome and the whole plant system. Further, we will look at the metabolic pathways of trichomes and their metabolic derivative's fates in the plant. Note: The project will either build off the pre existing "Molecular Biology" subparagraph, or incorporate a new paragraph on "Biochemistry and Metabolic Derivatives."

Review Paper: Understanding the Genetic pattern of differentiation in trichome genesis on the plant stem. Main take aways from the abstract: Random unicellular origination from an non differentiated epidermal cell. There are 20 known genes that influence trichome development. Trichome differentiation is not a cell lineage related pathway, but may possibly involve intercellular communication. This was accomplished using a GUS reporter gene insertion on the Ac transposon.

Mutations of genes controlling trichome production (ttg, gl1, dis1 etc) have affect on non-trichome related processes. Gl1 and Ttg epistatically control all other trichome transcription factors, as double mutants of both alleles are glabrous (hairless). Double recessive mutants for gl2 & gl3 show distorted morphology in trichome development when compared to wild type plants. Ttg mutants do not synthesize de novo anthocyanin flavonoid pigments, resulting in a brownish color and less protection from harmful environmental stressors (UV, temperature, herbivory). Ttg mutants also lack the ability to synthesize mucilage, a polysaccharide found on the outer embryo of plant seedlings. By studying Ttg , it was ascertained that trichome development is initiated in the tip (older tissue) and transcended to the base (younger tissue). The RTN allele is responsible in temporal activation of trichome synthesis by manipulating the length of time necessary in trichome induction signal pathways.

Findings from the primary research article "Morphology and Biochemistry of Non-Glandular Trichomes in Cistus salvifolius L. Leaves Growing in Extreme Habitats of the Mediterranean Basin".

Model Organsim: Cistus salvifolius

Main hypothesis, quoted: "Here, the hypothesis was tested that non-glandular trichomesmay have a role in the adaptive strategies ofC. salvifolius,asclerophyll shrub inhabiting seashore dunes of Italian coastalareas (Pignatti, 1982), against both high-light stress and thescarcity of soil nutrients (Margaris, 1981; Sandquist and Ehler-inger, 2003)."

Personal Notes

Ellagitannins are polyphenols that were identified by the researcher using coupling liquid chromatography and fluorescence. The processes of trichome metabolism was studied in reference to the impact on soil nitrogen composition after ellagitannin release and UV-A/UV-B absorption by monohydroxy B-ring substituted flavonoid, which is a mono/di-coumaryl monolignol derivative. Locating the polyphenols was the main contribution to the understanding of non-glandular trichome biochemistry.

Important note: The discussion here is focusing on the capacity of non-glandular (non secreting) trichomes to prevent against harmful UV exposure, as studied in extreme levels of heat and solar radiance. It has been shown that non-glandular trichomes are capable of this in previous species, but the exact mechanism was not elucidated. Presence of potential molecules in the trichome was found using epifluorescence microscopy and diphenylboric acid 2-amino-ethyl ester stains.

Data

The researchers data showed that the ellagitannins are responsible for coloration in the trichomes, indicating that non-glandular stellate and dendritic trichomes do in fact synthesize/store polyphenols ( kaempferol 3-O-gluco-side derivatives) used in solar radiance absorbance and plant protection from desiccation. Flavonoids were also located in trichrome arms of C. salvifolius, which were seen by using HPLC-DAD analysis (High-Performance Liquid Chromatography with Diode-Array Detection). They also confirmed that these flavonoids were coumaryl derivatives by using chromatographic profiling and UV-vis spectra. Autofluorescence absorption spectra were nearly identical to the kaempferol 3-O-gluco-side standard, indicating that the flavonoids were in fact derivatives of this molecule. Note: Acetylated Flavonoids have the ability to absorb short wavelength light of th UV-B spectrum compared to their non-acetylated counterparts.

Discussion and Implications

Flavonoids localized to the stellate and dendritic trichome structures protect the plant stem and leaves from penetrating and energetic UV-A and UV-B wavelength spectra. This may be the result of an adaptive mechanism in high solar radiation exposed plants. Further, trichomes are a necessary aspect of plant morphology in defense as leaves are often incapable of shielding the organism from harmful wavelengths as the cross sectional area of leaves do not suffice for efficient flavonoid distribution and thus absorption.