Plant Developmental Evolution
To see our lab's publications, please head to Madelaine's Google Scholar page.
We are interested in the molecular underpinnings of plant diversity. Which genes control the development of plants? And how have they changed over the course of evolution? Right now, we are tackling these questions through a few projects:
We are interested in the molecular underpinnings of plant diversity. Which genes control the development of plants? And how have they changed over the course of evolution? Right now, we are tackling these questions through a few projects:
The evolution of conserved non-coding sequences in green plantsIn a collaborative project with Idan Efroni (Israel), David Jackson (CSHL), and Zachary Lippman (CSHL, HHMI), we are working to identify deeply conserved cis-regulatory elements (CREs), including those that regulate developmental gene function, and to dissect the function of these CREs. As part of this work, we developed the ‘Conservatory’ algorithm, which identified cis-regulatory elements retained over deep time, detectable as conserved non-coding sequences (CNSs). The Conservatory database is available for you to explore.
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The development and evolution of floral sexualityMost flowering plants do not have genetic sex determination. Instead, they have developmental sex determination, where floral organ development helps determine gamete identity. Almost all flowers are built of the same four floral organ types: sepals (called paleas in the grasses), petals (called lodicules in the grasses), stamens, and pistils. Pistils, which develop into fruits after fertilization, produce ovules which contain two gametes - the egg and central cells. Stamens produce pollen grains which contain two sperm cells. Thus, the type of gametes formed – egg and central cell, or sperm cells – is determined by patterns of pistil and stamen development. Most flowers produce both pistils and stamens (‘bisexual’), but strictly pistillate and staminate flowers have arisen many times over the course of evolution, with consequences to gene flow, reproductive success, and crop yield. In collaboration with Sam Leiboff (OSU), we work to determine the mechanisms underlying the development of unisexual flowers, and the evolution of diversity in floral sexuality, with a specific focus on the grass family.
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The development and evolution of awnsMany grasses have specialized organ elaborations called awns that can function in grain development, grain dispersal, and seedling establishment. Awns usually extend from leaf homologs called lemmas. Although often simple and needle-like, awns can take on elaborate forms, and can have many roles. For example, many twisted and bent awns are hygroscopic. These awns twist and untwist as water content changes, burying seeds deeper underground, which can help with seedling establishment. Other awns are long and feathery, and may aid in wind dispersal. Yet others, like those of barley and wheat, contribute photosynthate to developing seeds and impact grain weight. Thus, awns are diverse in form and function, and can contribute to grass success. In collaboration with Annis Richardson (University of Edinburgh) and Dana MacGregor (Rothamsted Research), we work to dissect the genetic underpinnings of awn development and evolution.
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