Plant transposons: contributors to evolution?

Lönnig, Wolf-Ekkehard; Saedler, Heinz

doi:10.1016/s0378-1119(97)00397-1

Cited by 37 publications

(30 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An unusual feature of Tpn1 is that it contains a segment of DNA consisting of four exons that encode part of an HMG-box (High Mobility Group DNA-binding proteins) (29). This finding is consistent with the observation that transposable elements can cause rearrangements of the genome (30). Not only did Inagaki et al (28) establish that the observed sectoring phenotype was caused by the movement of this new transposable element, but the finding also established that, of the three DFR genes characterized, only one gene family member (DFR-B) is responsible for pigment production in the floral limb.…”

Section: Most Mutant Phenotypes Appear To Be the Results Of Transposonsupporting

confidence: 85%

Flower color variation: A model for the experimental study of evolution

Clegg

Durbin

2000

Proc. Natl. Acad. Sci. U.S.A.

143

View full text Add to dashboard Cite

We review the study of flower color polymorphisms in the morning glory as a model for the analysis of adaptation. The pathway involved in the determination of flower color phenotype is traced from the molecular and genetic levels to the phenotypic level. Many of the genes that determine the enzymatic components of flavonoid biosynthesis are redundant, but, despite this complexity, it is possible to associate discrete floral phenotypes with individual genes. An important finding is that almost all of the mutations that determine phenotypic differences are the result of transposon insertions. Thus, the flower color diversity seized on by early human domesticators of this plant is a consequence of the rich variety of mobile elements that reside in the morning glory genome. We then consider a long history of research aimed at uncovering the ecological fate of these various flower phenotypes in the southeastern U.S. A large body of work has shown that insect pollinators discriminate against white phenotypes when white flowers are rare in populations. Because the plant is selfcompatible, pollinator bias causes an increase in self-fertilization in white maternal plants, which should lead to an increase in the frequency of white genes, according to modifier gene theory. Studies of geographical distributions indicate other, as yet undiscovered, disadvantages associated with the white phenotype. The ultimate goal of connecting ecology to molecular genetics through the medium of phenotype is yet to be attained, but this approach may represent a model for analyzing the translation between these two levels of biological organization.flavonoid biosynthesis ͉ transposon ͉ spatial autocorrelation ͉ pollinator behavior ͉ morning glory T he study of adaptation is a problem that intersects all disciplines of biology. The study of adaptation is also among the most difficult and challenging areas of experimental research because a complete causal analysis of adaptation involves a translation between different levels of biological organization, the ecological, the phenotypic, and the molecular level (1). In this article we review more than 20 years of research on flower color polymorphisms in the common morning glory [Ipomoea purpurea (L.) Roth] that was aimed at exploring this interface.When the morning glory research program was initiated in the late 1970s, flower color polymorphisms appeared to be a natural starting point because (i) they represented simple discrete phenotypes that were susceptible to genetic analysis; (ii) a substantial body of work existed on the biochemistry of plant secondary metabolism; (iii) flower color was known to be important in insect pollinator behavior; and (iv) selection on reproductive performance should be among the most effective forms of selection, and, as a consequence, it should be the component of selection most likely to yield to experimental analysis. Virtually nothing was known in the late 1970s about the molecular biology of the genes that determine the anthocyanin pigments responsible for...

show abstract

Section: Most Mutant Phenotypes Appear To Be the Results Of Transposonsupporting

confidence: 85%

Flower color variation: A model for the experimental study of evolution

Clegg

Durbin

2000

Proc. Natl. Acad. Sci. U.S.A.

143

View full text Add to dashboard Cite

show abstract

“…The simplest interpretation of this finding is that T7 was transposed into the Tomato II segment after tomato and Arabidopsis diverged. Such a transposition may have been transposon-mediated-a mechanism well documented in plants (31,32).…”

Section: Evidence For a Transposition Event Into Tomato Ii?mentioning

confidence: 99%

Comparing sequenced segments of the tomato and Arabidopsis genomes: Large-scale duplication followed by selective gene loss creates a network of synteny

Vision

Liu

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

364

260

View full text Add to dashboard Cite

A 105-kilobase bacterial artificial chromosome (BAC) clone from the ovate-containing region of tomato chromosome 2 was sequenced and annotated. The tomato BAC sequence was then compared, gene by gene, with the sequenced portions of the Arabidopsis thaliana genome. Rather than matching a single portion of the Arabidopsis genome, the tomato clone shows conservation of gene content and order with four different segments of Arabidopsis chromosomes 2-5. The gene order and content of these individual Arabidopsis segments indicate that they derived from a common ancestral segment through two or more rounds of large-scale genome duplication eventspossibly polyploidy. One of these duplication events is ancient and may predate the divergence of the Arabidopsis and tomato lineages. The other is more recent and is estimated to have occurred after the divergence of tomato and Arabidopsis Ϸ112 million years ago. Together, these data suggest that, on the scale of BAC-sized segments of DNA, chromosomal rearrangements (e.g., inversions and translocations) have been only a minor factor in the divergence of genome organization among plants. Rather, the dominating factors have been repeated rounds of large-scale genome duplication followed by selective gene loss. We hypothesize that these processes have led to the network of synteny revealed between tomato and Arabidopsis and predict that such networks of synteny will be common when making comparisons among higher plant taxa (e.g., families). genome evolution ͉ polyploidy

show abstract

“…In different accessions of maize, the genes encoding these proteins have been variously amplified, such that genes encoding functionally equivalent proteins are active in different tissues of the vegetative and reproductive phases of growth (Chandler et al, 1989;Cone et al, 1993;Pilu et al, 2003). Some of the resultant variation in plant pigment patterning may be attributable to human selection for more exotic pigmentation forms, because such lines were highly prized by the indigenous peoples of Central America (Lonnig and Saedler, 1997). In maize, an additional gene, pac1, encodes a WD repeat protein that affects the levels of anthocyanin production in kernels (Carey et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

A Small Family ofMYB-Regulatory Genes Controls Floral Pigmentation Intensity and Patterning in the GenusAntirrhinum

et al. 2006

View full text Add to dashboard Cite

The Rosea1, Rosea2, and Venosa genes encode MYB-related transcription factors active in the flowers of Antirrhinum majus. Analysis of mutant phenotypes shows that these genes control the intensity and pattern of magenta anthocyanin pigmentation in flowers. Despite the structural similarity of these regulatory proteins, they influence the expression of target genes encoding the enzymes of anthocyanin biosynthesis with different specificities. Consequently, they are not equivalent biochemically in their activities. Different species of the genus Antirrhinum, native to Spain and Portugal, show striking differences in their patterns and intensities of floral pigmentation. Differences in anthocyanin pigmentation between at least six species are attributable to variations in the activity of the Rosea and Venosa loci. Set in the context of our understanding of the regulation of anthocyanin production in other genera, the activity of MYB-related genes is probably a primary cause of natural variation in anthocyanin pigmentation in plants.

show abstract

Plant transposons: contributors to evolution?

Cited by 37 publications

References 45 publications

Flower color variation: A model for the experimental study of evolution

Flower color variation: A model for the experimental study of evolution

Comparing sequenced segments of the tomato and Arabidopsis genomes: Large-scale duplication followed by selective gene loss creates a network of synteny

A Small Family ofMYB-Regulatory Genes Controls Floral Pigmentation Intensity and Patterning in the GenusAntirrhinum

Contact Info

Product

Resources

About