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Ann LT Powell

Professional Research Biochemist

Plant Science

Plant Reproductive Biology Bldg., Rm 1143


1976 PhD University of Washington Biochemistry
1971 BA Stanford University Biological Sciences

Research Interests:

My primary research interest is to understand the roles of enzymes and proteins in developing and ripening fruit. I have three major research topics: 1. Identify functions in green fruit that can improve the resistance of red fruit to pathogens, 2. Determine how Golden 2-like transcription factors regulate chloroplasts in fruit prior to ripening, 3. Characterize proteins and enzymes that modify the plant cell wall during fruit ripening, 4. Develop transgenic rootstocks for grafting to improve scion products. I work primarily with tomato and Arabidopsis but have also worked with strawberry and melons. Our group works with necrotrophic fungal pathogens and transgenic plants to investigate the functions of proteins and enzymes. I have taught an undergraduate lab course on techniques used in research in the plant sciences (BIT 161B) and a course on scientific writing and proposal preparation (BIT/PLB188).

Department and Center Affiliations:

Plant Sciences Department, Section Agricultural Plant Biology
Plant Genome Affiliation Group

Professional Societies:

Molecular Plant Microbe Interactions
Association of Plant Biologists
Association of Women in Sciences

CBS Graduate Group Affiliations:

Plant Biology  

Specialties / Focus:

Plant Biology
Cell and Developmental Biology


Last updated 8/14/2012
40. Powell AL, Nguyen CV, Hill T, Cheng KL, Figueroa-Balderas R, Aktas H, Ashrafi H, Pons C, Fernández-Muñoz R, Vicente A, Lopez-Baltazar J, Barry CS, Liu Y, Chetelat R, Granell A, Van Deynze A, Giovannoni JJ, Bennett AB. 2012. Uniform ripening encodes a Golden 2-like transcription factor regulating tomato fruit chloroplast development. Science 336:1711-1515.

39. Shah P, Gutierrez-Sanchez G, Cantu D, Powell, ALT, Orlando R, Bergmann C. 2012. A proteomic analysis of ripening tomato fruit infected by Botrytis cinerea. J Proteome Research 11:2178-2192.

38. Haroldsen V, Szczerba M, Aktas H, Lopez-Baltazar J, Odias MJ, ChiHam C, Labavitch JM, Bennett AB, Powell ALT. 2012. Delivery of nucleic acids and proteins from grafted rootstocks for pathogen and pest control. Frontiers in Plant Sciences 3:39. http://www.frontiersin.org/plant-microbe_interaction/10.3389/fpls.2012.00039/abstract; doi: 10.3389/fpls.2012.00039

37. Blanco-Ulate B, Cantu D, Wang H, Bennett AB, Labavitch JM, Powell ALT. 2011. Modifications in Tomato Fruit Ripening alter Susceptibility to the Pathogenic Fungus Botrytis cinerea. Acta Horticulturae 906:161-170.

36. Cantu D, Greve LC, Labavitch JM, Powell ALT. 2009. Characterization of the cell wall of the ubiquitous plant pathogen Botrytis cinerea. Mycological Research 113:1396-1403.

35. Cantu D, Blanco-Ulate B, Yang L, Labavitch JM, Bennett AB, and Powell ALT. 2009. Ripening regulated susceptibility of tomato fruit to Botrytis cinerea requires NOR but not RIN or ethylene. Plant Physiol.150:1434-1449.

34. Cantu D, Vicente AR, Labavitch JM, Bennett AB, Powell ALT. 2008. Strangers in the matrix: plant cell wall and pathogen susceptibility. Trends in Plant Sciences.11:610-617.

33. Celorio-Mancera M de la P, Allen ML, Powell AL, Ahmadi H, Salemi MR Phinney,BS, Shackel, KA, Greve, LC, Teuber, LR, Labavitch, JM. 2008. Cloning and identification of western tarnished plant bug (Lygus hesperus) polygalacturonases secreted during feeding. Arthropod Plant Interactions 2:215-225.

32. Cantu D, Vicente AR, Greve LC, Dewey FM, Bennett AB, Labavitch JM and Powell ALT. 2008. The intersection between cell wall disassembly, ripening and fruit susceptibility to B. cinerea. Proc. Natl. Aca. Sci. USA. 105: 859-864

31. Cantu D, Vicente AR, Greve LC, Labavitch JM, Powell ALT. 2007. Genetic determinants of textural modifications in fruits and role of cell wall polysaccharides and defense proteins in the protection against pathogens. Fresh Produce 1:1-10.

30. Vicente AR, Powell A, Greve LC, Labavitch JM. 2007. Cell wall disassembly events in boysenberry (Rubus idaeus L. x Rubus ursinus Cham. & Schldl.) fruit development. Functional Plant Biology 34:614-623.

29. Vicente AR, Ortugno C, Rosli H, Powell Ann LT, Greve C, Labavitch J. 2007. The temporal sequence of cell wall disassembly events in developing fruits: 2. Analysis of blueberry. J Agric. Food Chem. 55:4125-30.

28. Vicente AR, Ortugno C, Powell Ann LT, Greve C, Labavitch JM. 2007. The temporal sequence of cell wall disassembly events in developing fruits: 1. Analysis of raspberry. J Agric. Food Chem. 55:4119-4124.

27. Vicente, Ariel, Civello, Marcos, Martínez, GA, Powell, ALT, Labavitch, JML, Chaves Alicia. 2005. Control of postharvest spoilage in soft fruit. Stewart Postharvest Review Journal. 1: 1-11. (http://www.stewartpostharvest.com/December_2005/Vicente.pdf).

26. Rousseaux MC, Jones C, Adams D, Chetelat R, Bennett A, Powell,A. 2005. Genetic analysis of ascorbic acid, phenolic and antioxidant fruit QTL in Lycopersicon pennellii. Theoretical and Applied Genetics 111:1396-1408.

19. Agüero C B., Uratsu S L, Greve LC, Powell ALT, Labavitch JM, Meredith CP, Dandekar AM. 2005. Evaluation of tolerance to Pierce’s Disease and Botrytis in transgenic plants of Vitis vinifera L. expressing the pear PGIP gene. Mol. Plant Path. 6:43-51.

18. D'hallewin G, Schirra M, Powell ALT, Greve LC, Labavitch JM. 2004. Properties of a polygalacturonase-inhibiting protein from 'Oroblanco' grapefruit. Physiologia Plantarum 120:395-404.

24. Kalamaki MS, Powell ALT, Struijs K, Labavitch, JM, Reid DS, Bennett, AB. 2003. Transgenic over-expression of expansin influences particle size distribution and improves viscosity of tomato juice and paste. J. Agricultural and Food Chem. 51:7465-7471.

23. Stotz, Henrik U., Elad, Yigal, Powell, Ann L.T., Labavitch, John M. 2004. Chapter 20: “Innovative biological approaches to Botrytis suppression.” In: Botrytis spp.: A comprehensive treatise. Kluwer Academic Publishers, The Netherlands. (Y. Elad, B. Williamson, P. Tudzynski, N. Delen, Eds.). Pp.369-392.

22. Powell ALT, Kalamaki MS, Kurien PA, Gurrieri S, Bennett AB. 2003. Simultaneous transgenic suppression of LePG and LeExp1 influences fruit texture and juice viscosity in a fresh market tomato variety. J. Agricultural and Food Chemistry 51:7450-7455

21. Thornburg, R, Carter C, Powell A, Horner HH, Rizhsky L, Mittler R. 2003. A major function of the nectary gland is plant defense against microbial attack. Plant Syst. Evol. 238:211-218.

20. Powell, A.L.T. and A.B. Bennett. 2002. Chapter: “Tomato” In: Fruit and Vegetable Biotechnology. Woodhead Publishing Ltd., Cambridge, UK (Victoriano Valpuest, Ed.).

19. Gurusinghe S., Powell ALT, Bradford KJ. 2002. Enhanced expression of BiP is Associated with treatments that extend storage Longevity of primed tomato seeds. J. Amer. Soc. Hort. Sci. 127 (4): 528-534.

18. Powell ALT, van Kan J, ten Have A, Visser J, Greve LC, Bennett AB, Labavitch JM. 2000. Transgenic expression of pear PGIP in tomato limits fungal colonization. Mol. Plant Microbe Interactions 13:942-950.

17. Civello PM, Powell A, Sabehat A, Bennett AB. 1999. An expansin gene expressed in ripening strawberry fruit. Plant Physiol. 121:1-7.

16. Kanayama Y, Granot D, Dai N, Petreikov M, Schaffer A, Powell A, Bennett AB. 1998. Tomato fructokinases exhibit differential expression and substrate regulation. Plant Physiol. 117:85-90.

15. Labavitch, J.M., Greve, L.C., Powell, A.L.T., Bennett, A.B. and Sharrock. K.R. 1997. “Polygalacturonase inhibitor proteins - do they contribute to fruit defense against fungal pathogens?” In: Disease resistance in fruit. ACIAR Proceedings No. 80. (Johnson, G.I., Johce, D.C. and Highley, E., eds.).

14. Powell, A.L.T., Stotz, H.U., Labavitch, J.M. and Bennett, A.B. 1995. “Glycoprotein Inhibitors of Fungal Polygalacturonases.” In: Advances in Molecular Genetics of Plant-Microbe Interactions, Vol. III. Kluwer Academic Publishers, Boston, MA (M.J. Daniels, J.A., Downie, A.E. Osborne, Eds.) pps. 399-402.

13. Stotz HU, Contos JA, Powell ALT, Bennett AB, Labavitch JM. 1994. Structure and expression of an inhibitor of fungal polygalacturonases from tomato. Plant Mol. Biol. 25:607-617.

12. Stotz HU, Powell ALT, Damon SE, Greve LC, Bennett AB, Labavitch JM. 1993. Molecular characterization of a polygalacturonase inhibitor from Pyrus communis L. cv Bartlett. Plant Physiol. 102:133-138.

11. Kanemoto R, Powell ALT, Akiyoshi DE, Regier DA, Kerstetter RA, Nester EW, Hawes MC, Gordon MP. 1989. Nucleotide sequence and analysis of the plant-inducible locus pinF from Agrobacterium tumefaciens. J. of Bacteriology 171:2506-2512.

10. Powell, A.L.T. and Gordon, M.P. 1989. “Plant Tumor Formation.” In: The Biochemistry of Plants: A Comprehensive Treatise. Vol. 15, Acad. Press, Orlando, Fl. (A. Marcus, Ed.) pp 617-651.

9. Amasino RM, Powell ALT, Gordon MP. 1984. Changes in T-DNA methylation and expression are associated with phenotypic variation and plant regeneration in a crown gall tumor line. Mol. Gen Genet. 197:437-446.

8. Gordon, M., Garfinkel, D., Klee, H., Knauf, V., Kwok, W., Lichtenstein C., McPherson J., Montoya, A., Nester, E., O’Hara, P., Powell, A., Ream L.W., Simpson, R., Taylor, B., and White, F. 1982. “Crown Gall - Nature’s Genetic Engineer.” In: From Gene to Protein: Translation into Biotechnology, Acad. Press, Inc., Orlando, Fl., pp.105-125.

7. Thomashow MF, Nutter R, Postle K, Chilton MD, Blattner FR, Powell A, Gordon MP, Nester EW. 1980. Recombination between Higher Plant DNA and the Ti-plasmid of Agrobacterium tumefaciens. Proc. Natl. Acad. Sci. USA 77:6448-6452.

6. King W, Thomas-Powell AL, Raab-Traub N, Hawke M, Kieff E. 1980. Epstein-Barr Virus RNA. V. Viral RNA in a restringently infected growth-transformed cell line. J. Virol. 36:506-518.

5. Kieff E, Given D, Powell A, King W, Dambaugh T, Raab-Traub N. 1979. Epstein-Barr Virus: Structure of the viral DNA and analysis of viral RNA in infected cells. Biochim. Biophy. Acta Reviews on Cancer 560:355-373.

4. Powell ALT, King W, Kieff E. 1979. Epstein-Barr Virus Specific RNA. III. Mapping of DNA encoding viral RNA in restringent infection. J. Virol. 29:261-274.

3. Keiff, E., Raab-Traub, N., Given, D., King, W., Powell, A., Pritchett, R. and Dambaugh, T. 1978. “Mapping of Putative Transforming Sequences of EBV DNA.” In: Oncogenesis and Herpesviruses III, Part I, F. Rapp and G. de The (Eds.), I.A.R.C., Lyon, pp 527-552.

2. Powell ALT, Gordon MP, Caspary WJ, Greene JJ, Ts'o POP. 1978. Studies on spin labeled ribonucleic acids encapsulated by viral proteins. Nucleic Acid Research 5:3977-3992.

1. Kidson D, Thomas AL, Cohen P. 1970. Interactions of hormonal steroids in nucleic acids: III. Role of polymer structure. Biochemistry 9:1571-1576.

Laboratory Personnel:

A Powell lab

Teaching Interests:

Undergraduate Research Proposal preparation - BIT188. This course is intended for students actively participating in undergraduate research, or who plan to do so in the near future. This is a writing intensive course that can be considered a laboratory in scientific writing, You will learn how to define a research problem with a faculty mentor, how to design well-controlled experiments, and how to present your ideas to others. http://www.plantsciences.ucdavis.edu/Classes_2006/BIT_188_2006/index.htm


BIT 188 Undergraduate Research Proposal preparation Spring
BIT 161B Plant genetics and biotechnology Winter

Key Words:

Fruit quality, development, pathogen resistance, chloroplast, grafting