Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Litt, Amy [1], Strahl, Maya [2], McCarthy, Elizabeth [2], Meyer, Rachel [3], Mora, Natalia Pabon [4].

The role of FRUITFULL genes in fruit development in Solanaceae.

The Solanaceae provide an wonderful system in which to study the genetic basis and evolution of morphological diversity: there is significant morphological variation, study of gene function is feasible in many species, and a wealth of genomic and and other resources is available. We are interested in fruit diversity in Solanaceae, and in an analysis comparing transcriptomes of early developing fruit of tomato (Solanum lycopersicum) and wood tobacco (Nicotiana sylvestris), we found differential expression of an ortholog of FUL, a key regulator of fruit development in Arabidopsis thaliana. A gene tree analysis suggests that members of the fleshy-fruited Solanoideae clade, which includes Solanum, have four FUL paralogs, whereas earlier diverging taxa including Nicotiana have three. We are therefore investigating the role of these genes in fruit development and testing the hypothesis that the additional duplication in Solanoideae may be related to the development of fleshy fruit. We used virus induced gene silencing (VIGS) to downregulate SlFUL2 in tomato; our results and those of other labs show that reduction in transcript of this genes results in an increase in branching, defects in flower organ development (notably stamen cone formation), decreased time to ripening, defects in fruit size, shape, and color, and decreased pericarp thickness. Although some of these functions have been attributed to FUL or its orthologs in other species, others, such as regulation of cell division in the pericarp, were novel; this feature is also of interest because an increase in the number of cell layers in the pericarp is one of the features that distinguishes dry and fleshy fruit development in Solanaceae. Preliminary studies of the function of the ortholog in N. sylvestris showed only defects in sepal morphology and senescence, however, we have shifted our efforts to N. obtusifolia (desert tobacco). This diploid species grows easily in small pots, stays small, and flowers rapidly and profusely. Preliminary VIGS analyses in this species resulted in plants with shortened internodes and shorter corollas but no apparent defects in fruit development. To further develop this new species for developmental genetic work, we have generated leaf, inflorescence, and fruit transcriptome data and are collaborating on a mutagenesis screen. We are currently performing VIGS on the other FUL paralogs in both species, and are generating stable transformants for further analysis.

Broader Impacts:

1 - New York Botanical Garden, 200th St And Southern Blvd., Bronx, NY, 10458, USA
2 - The New York Botanical Gareden, 2900 Southern Blvd, Bronx, NY, 10458, USA
3 - New York University, New York, NY, USA
4 - Universidad de Antioquia, Medellin, Colombia

Keywords:
Solanaceae
fruit development
fruit evolution
FUL
tomato
tobacco.

Presentation Type: Oral Paper:Papers for Topics
Session: 42
Location: Jasperwood/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 11:15 AM
Number: 42005
Abstract ID:277
Candidate for Awards:None