Cultivated
tomato represents a diverse collection of plants that vary in
many traits such as fruit morphology. The diversity in fruit
morphology provides a rich source for studies on fruit
development and organ patterning. The understanding of the
molecular and genetic bases of diversity in fruit form will
allow insights into evolutionary processes of tomato
domestication and selection. This information will guide
future experiments aimed at increasing our understanding of
domestication of other fruit and vegetable crops. A historical
overview of the origin of tomato and the first recordings of the
different morphologies is described here
(Tomato Fruit Morphology).
Morphogenesis
is a critical process in all multicellular organisms and one
that is characterized by extreme complexity and substantial
diversity among organ types and species. The focus on tomato
fruit morphology allows us to gain detailed insights into the
identity and function of candidate and master regulator genes
with the goal to discover the underlying mechanisms of fruit
formation. The approach we are taking is multifaceted and
integrated, and will lead to significant advances in the
understanding of basic plant growth processes. Ultimately, a
better understanding of how fruit morphology is regulated will
lead to more efficient approaches to develop new varieties with
specific morphological traits.
The
main objectives of the tomato fruit morphology project are i) to
identify and characterize genes controlling tomato fruit shape
and size, and ii) to discover the underlying molecular networks
that control fruit morphogenesis. To do so, transcript,
metabolite and hormone profiles will be generated for genes
controlling tomato morphology while new shape and size genes
will be genetically mapped and cloned. Furthermore, tomato
fruit shapes will be described in mathematical terms to aid
standardization and classification of the diverse fruit types.
Lastly, models of the molecular networks present in tomato
connecting gene expression, hormone and metabolite accumulation
with morphology will be generated. The co-investigators of this
project are: Carmen Catalá (Boyce Thompson Institute), Brian
McSpadden Gardener (Ohio State/OARDC), Sofia Visa (The College
of Wooster). The collaborators of this project are: Carri Gerber
(Ohio State/ATI), Yuji Kamiya (RIKEN, Yokohama Japan), Kazuki
Saito (RIKEN and Chiba University, Chiba Japan), Simon Gray,
John Ramsay (The College of Wooster). More information about
this project can be found at
http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0922661
Collaborative projects:
This project
revolves around Single Nucleotide Polymorphism (SNP) discovery
and application in tomato.
This project is in collaboration with Drs. Allen van
Deynze (UC-Davis) and David Francis (Ohio State) and is intended
to improve DNA-based marker availability for breeding
populations of tomato. More information can be found at
http://www.oardc.ohio-state.edu/tomato/translational_genomics.htm.
and
project summary.
The second project focuses on characterizing fruit size and
quality traits in cherry. This project is in collaboration with
Drs. Amy Iezzoni, Wayne Loescher, and Dechun Wang (Michigan
State). The goal of
this project is the development of the genomic resources needed
to implement marker-assisted selection in cherry (Prunus
sp.) breeding programs.
We plan to accomplish this goal with a standard QTL strategy
focused on fruit size and quality traits followed by QTL
validation and allele mining.
More information on the
cherry project can be found at
http://www.cherrygenetics.org/
and
project summary
Another collaborative project centers on interspecies barriers
in the tomato clade. The specific aims are to identify
genes responsible for the recognition and rejection of pollen
from closely related species. PI of this project is Pat Bedinger
(Colorado State) and coPIs/collaborators are Bruce McClure (U of
Missouri), Roger Chetelat (UC Davis), Joss Rose (Cornell), Steve
Stack (Colorado State). More information can be found at
http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0605200
Another collaborative project focuses
on the role of auxin in fruit set. Adverse environmental
conditions that reduce seed set (such as unfavorable weather or
absence of insect pollinators) reduce fruit formation, resulting
in lower yields for growers. To obtain more reliable production
and to satisfy consumer demand, breeders often select for
seedless varieties. The purpose of the project is to obtain
detailed knowledge of the molecular pathways by which the
hormone auxin regulates fruit initiation. This project is in
collaboration with Jason Reed at the University of North
Carolina. More information can be found at:
http://cris.csrees.usda.gov/cgi-bin/starfinder/0?path=fastlink1.txt&id=anon&pass=&search=R=2341&format=WEBLINK