Award Abstract #0211742
Functional Analyses of Plant Gamete Gene Expression

NSF Org:	IOS Division of Integrative Organismal Systems
Initial Amendment Date:	August 15, 2002
Latest Amendment Date:	August 15, 2002
Award Number:	0211742
Award Instrument:	Standard Grant
Program Manager:	Diane Jofuku Okamuro IOS Division of Integrative Organismal Systems BIO Directorate for Biological Sciences
Start Date:	September 1, 2002
Expires:	August 31, 2007 (Estimated)
Awarded Amount to Date:	$1135486
Investigator(s):	Sheila McCormick sheilamc@nature.berkeley.edu (Principal Investigator)
Sponsor:	University of California-Berkeley Sponsored Projects Office BERKELEY, CA 94704 510/642-8109
NSF Program(s):	PLANT GENOME RESEARCH PROJECT
Field Application(s):
Program Reference Code(s):	BIOT, 9184, 9109
Program Element Code(s):	1329

ABSTRACT

In higher plants, each pollen grain contains two sperm cells that are delivered to the embryo sac. One sperm fertilizes the egg and this fusion gives rise to the embryo that eventually grows into the plant. The other sperm fertilizes another cell in the embryo sac and this second fusion gives rise to the endosperm, a nutritive tissue in the seed that is required for the development of the embryo. Double fertilization is arguably the developmental process of most economic value in crop plants, because most foods are seeds or arise from seeds. Double fertilization was discovered over 100 years ago. But because of the relative inaccessibility of plant gametes, the molecular biology and mechanistics of this unique feature of the higher plant life cycle are barely understood. In order to exploit gametes for crop improvement, it is necessary to know more about them.

To facilitate a more global understanding of plant gamete gene expression, cDNA libraries will be constructed from isolated sperm, eggs, and embryo sacs of maize. More than 5000 cDNAs from each library will be sequenced. Expression profiles for about 200 diverse cDNAs from each library will be determined. Plants with fluorescently-tagged gametes will be constructed to facilitate analysis of gamete function in gene disruption lines, and to facilitate imaging of fertilization. Functional analyses will focus on genes predicted to encode surface-localized proteins that might mediate critical cellular interactions during double fertilization. All sequences and stocks from this project will be available to the research community. With this information about maize gamete gene expression, comparative genomics can be used to identify and manipulate gamete-expressed genes in diverse plant species.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

Engel, Michelle Holmes-Davis, Rachel McCormick, Sheila. "Green sperm. Identification of male gamete promoters in Arabidopsis thaliana.," Plant Physiology, v.138, 2005, p. 2124.

McCormick, S.. "Control of Male Gametophyte Development," The Plant Cell, v.16, 2004, p. online.

McCormick, Sheila Yang, Heping. "Is there more than one way to attract a pollen tube?," Trends in Plant Science, v.10, 2005, p. 260.

Michele Engel, Annie Chaboud, Christian Dumas and Sheila McCormick. "Sperm cells of Zea mays have a complex complement of mRNAs.," The Plant Journal, v.34, 2003, p. 697.

Yang, Heping, Navpreet Kaur, Stephanie Kiriakopolos, Sheila McCormick. "EST generation and analyses towards identifying female gametophyte-specific genes in Zea mays L.," Planta, v.224, 2007, p. 1004.

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