A collection of research articles explores developments in interfacial transport and mixing, with wide-ranging practical applications.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Edited by Martin F. Yanofsky, University of California at San Diego, La Jolla, CA, and approved February 23, 2011 (received for review September 27, 2010)
Abstract
Although the biological function of fruiting is the production and dissemination of seeds, humans have developed seedless fruits in a number of plant species to facilitate consumption. Here we describe a unique spontaneous seedless mutant (Thai seedless; Ts) of Annona squamosa (sugar apple), a member of the early-divergent magnoliid angiosperm clade. Ovules (seed precursors) of the mutant lack the outer of two normal integuments, a phenocopy of the inner no outer (ino) mutant of Arabidopsis thaliana. Cloning of the INO ortholog from A. squamosa confirmed conservation of the outer integument-specific expression pattern of this gene between the two species. All regions of the gene were detectable in wild-type A. squamosa and in other members of this genus. However, no region of the INO gene could be detected in Ts plants, indicating apparent deletion of the INO locus. These results provide a case of a candidate gene approach revealing the apparent molecular basis of a useful agronomic trait (seedless fruit) in a crop species, and indicate conservation of the role of a critical regulator of ovule development between eudicots and more ancient lineages of angiosperms. The outer integument is one synapomorphy of angiosperms separating them from other extant seed plants, and the results suggest that the evolution of this structure was contemporaneous with the derivation of INO from ancestral YABBY genes. Thus, a unique lateral structure appears to have coevolved with a novel gene family member essential for the structure's formation.
Footnotes
- 1To whom correspondence should be addressed. E-mail: csgasser{at}ucdavis.edu.
Author contributions: J.L., J.I.H., M.H., and C.S.G. designed research; J.L., J.I.H., and C.S.G. performed research; J.L., J.I.H., M.H., and C.S.G. analyzed data; and J.L., J.I.H., M.H., and C.S.G. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. GU828032, GU828033, HM237356, and HM237357).
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1014514108/-/DCSupplemental.
- aInstituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Consejo Superior de Investigaciones Cientificas (CSIC), 29750 Algarrobo-Costa, Málaga, Spain;
- bDepartment of Molecular and Cellular Biology, University of California, Davis, CA 95616; and
- cDepartamento de Pomoligía, Estación Experimental “Aula Dei,” CSIC, 50080 Zaragoza, Spain
Edited by Martin F. Yanofsky, University of California at San Diego, La Jolla, CA, and approved February 23, 2011 (received for review September 27, 2010)
Abstract
Although the biological function of fruiting is the production and dissemination of seeds, humans have developed seedless fruits in a number of plant species to facilitate consumption. Here we describe a unique spontaneous seedless mutant (Thai seedless; Ts) of Annona squamosa (sugar apple), a member of the early-divergent magnoliid angiosperm clade. Ovules (seed precursors) of the mutant lack the outer of two normal integuments, a phenocopy of the inner no outer (ino) mutant of Arabidopsis thaliana. Cloning of the INO ortholog from A. squamosa confirmed conservation of the outer integument-specific expression pattern of this gene between the two species. All regions of the gene were detectable in wild-type A. squamosa and in other members of this genus. However, no region of the INO gene could be detected in Ts plants, indicating apparent deletion of the INO locus. These results provide a case of a candidate gene approach revealing the apparent molecular basis of a useful agronomic trait (seedless fruit) in a crop species, and indicate conservation of the role of a critical regulator of ovule development between eudicots and more ancient lineages of angiosperms. The outer integument is one synapomorphy of angiosperms separating them from other extant seed plants, and the results suggest that the evolution of this structure was contemporaneous with the derivation of INO from ancestral YABBY genes. Thus, a unique lateral structure appears to have coevolved with a novel gene family member essential for the structure's formation.
- cherimoya
- stenospermy
- parthenocarpy
Footnotes
- 1To whom correspondence should be addressed. E-mail: csgasser{at}ucdavis.edu.
Author contributions: J.L., J.I.H., M.H., and C.S.G. designed research; J.L., J.I.H., and C.S.G. performed research; J.L., J.I.H., M.H., and C.S.G. analyzed data; and J.L., J.I.H., M.H., and C.S.G. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. GU828032, GU828033, HM237356, and HM237357).
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1014514108/-/DCSupplemental.
Seedless fruits and the disruption of a conserved genetic pathway in angiosperm ovule development
Sign up for Article Alerts
Jump to section
You May Also be Interested in
Quantum computers capture headlines, but a quieter revolution in the world of sensors may be just as profound.
Image credit: Ola J. Joensen (Niels Bohr Institute, Copenhagen, Denmark).
Opinion: To advance sustainable stewardship, we must document not only biodiversity but geodiversity
Key abiotic features and processes should be incorporated into policy documents.
Image credit: Shutterstock/1968.
Researchers report a marine ammonite from the Cretaceous Period preserved in Burmese amber from Myanmar, and the rare specimen in amber warrants exploration of the possibly exceptional circumstances of its fossilization.
Image courtesy of Bo Wang.
Exposure to low humidity makes mice infected with influenza more susceptible to severe disease by impairing airway tissue repair and innate antiviral defense, suggesting that controlling humidity may help curb influenza during winter.
Image courtesy of Pixabay/qimono.