Research Proposal For Aspects Of Arabidopsis Thaliana

Essay, Research Paper

Research Proposal for Aspects of Arabidopsis thaliana Introduction The mouse

ear cress Arabidopsis thaliana is a member of the Brassicaeae that lends

itself well to genetic study in that it has only a small quantity of DNA. The

plant itself has little commercial value aside from that as a research tool,

and it has no aesthetic horticultural value at all. It is a small plant that

can be grown by the hundreds in cells on a laboratory bench, and its small

quantity of DNA makes it useful in identifying genes of other organisms

(Wheeler, 1994). Normal

flower color varies between solid white petals to green petals only tinged with

white. Manipulation of flower color is of interest not because of any potential

ornamental value, but because of the mechanisms of gene expression in the

visible appearance of the yellow pigment anthocyanin. In like

manner, information regarding cold tolerance and the biochemical changes that

occur within the plant in response to cold are not of interest primarily for

culture of the plant itself except as it applies to cultural conditions that

need to be maintained for optimum life cycle completion time. Rather, Arabidopsis?

response to cold stress is of interest because facts learned from it can be

applied to investigations in human systems (Stockinger, Gilmour and Thomashow,

1997). This investigation seeks to determine if enough anthocyanin can be

concentrated in petal cells so that they express a visible yellow color, and if

cold stress has any effect on visible levels of anthocyanin concentrations in

petal cells. Literature

Review

Arabidopsis

naturally contains anthocyanin, and Lloyd, Walbot and Davis (1992) were able to

cause anthocyanin "pathway-specific transcriptional activators R and C1

from the monocot maize were expressed in two dicots, Arabidopsis thaliana

and Nicotiana tabacum. Expression of R caused augmented anthocyanin

pigmentation in both plant species and augmented trichome (hair) production in Arabidopsis"

(p. 1773), but C1 had no effect alone. Expression of both in Arabidopsis

resulted in expression of anthocyanins in tissues that normally contain none,

such as root, petal and stamen tissues. In more recent research, Walker,

Davison, Bolognesi-Winfield, James, Srinivasean, Blundell, Esch, Marks and Gray

(1999), the researchers isolated by positional cloning the transparent testa

glabra1 (TTG1) locus they had previously determined as regulating development

of anthocyanins in Arabidopsis.