Department of Botany & Plant Sciences

College/Division Affiliation:

College of Natural and Agricultural Sciences

Areas Of Expertise:

Karrikin and strigolactone signaling networks; evolution of host-sensing in parasitic plants and post-fire germination; synthetic biology; engineering parasitic weed resistance in crops

Awards / Honors:

2016                            University of GeorgiaCenter for Teaching and Learning, Fellow for Innovative Teaching

2010                            Carnegie Fellow

2005                            Wisconsin Distinguished Graduate Fellowship – Morgridge Biotechnology Fellow

2004                            HHMI Teaching Fellowship in Classroom Teaching

2002                           Gamma Sigma Delta (Honor Society of Agriculture)

Research Summary:

Our research is focused on understanding how plant growth is regulated by karrikins, a class of germination-promoting chemicals found in smoke, and strigolactones, a recently recognized class of plant hormones. Although karrikins and strigolactones have unique effects and sources, remarkably they appear to act through parallel signaling mechanisms. We use genetic approaches to determine how these signals produce different responses, and we are investigating how evolution of these signaling mechanisms has enabled host-triggered germination in parasitic weeds and post-fire germination among many smoke-responsive species. We are also exploring translational applications of our research to reduce crop losses to parasitic weeds.  

Related Press Releases:

Science News for Students, September 1, 2015: Plant ‘vampires’ lay in wait http://tinyurl.com/o42yhzf

The Scientist, August 1, 2013: Smoke Detectors http://tinyurl.com/praue7x

Selected Publications:

 Google Scholar profile: https://goo.gl/6b2tkK

Khosla A, Nelson DC. (2016) “Strigolactones, super hormones in the fight against Striga.” Current Opinion in Plant Biology, 33:57-6.

Lopez-Obando M, Conn CE, Hoffmann B, Bythell-Douglas R, Nelson DC, Rameau C, Bonhomme S. (2016) “Structural modelling and transcriptional responses highlight a clade of PpKAI2-LIKE genes as candidate receptors for strigolactones in Physcomitrella patens.” Planta, 243(6):1441-53.

Stanga JP, Morffy N, Nelson DC. (2016) “Functional redundancy in the control of seedling growth by the karrikin signaling pathway.” Planta, 243(6):1397-1406.

Morffy N^‡, Faure L^‡, Nelson DC. (2016) “Smoke and hormone mirrors: action and evolution of karrikin and strigolactone signaling.” Trends in Genetics, 32(3):176-88.

Conn CE, Nelson DC. (2016) “Evidence that KARRIKIN-INSENSITIVE2 (KAI2) receptors may perceive an unknown signal that is not karrikin or strigolactone.” Frontiers in Plant Science, 6:1219. 

Soundappan I^‡, Bennett T^‡, Morffy N, Yueyang L, Stanga JP, ^UGAbbas A, Leyser O, Nelson DC. (2015) “SMAX1-LIKE/D53 family members enable distinct MAX2-dependent responses to strigolactones and karrikins in Arabidopsis.” Plant Cell, 27:3143-59.

Conn CE, Bythell-Douglas R, ^UGNeumann D, Yoshida S, Whittington B, Westwood JH, Shirasu K, Bond CS, Dyer KA, Nelson DC. (2015) “Convergent evolution of strigolactone perception enabled host detection in parasitic plants.” Science, 349:540-43.

Stanga JP, Smith SM, Briggs WR, Nelson DC. (2013) “SUPPRESSOR OF MORE AXILLARY GROWTH2 1 Controls Seed Germination and Seedling Development in Arabidopsis.”Plant Physiology, 163(1):318-30.

Nelson DC, Flematti GR, Ghisalberti EL, Dixon KW, Smith SM. (2012) “Regulation of seed germination and seedling growth by chemical signals from burning vegetation.” Annual Reviews of Plant Biology, 63: 107-130.

Waters MT, Nelson DC, Scaffidi A, Flematti GR, ^UGSun Y, Dixon KW, Smith SM. (2012) “Specialisation within the DWARF14 protein family confers distinct responses to karrikins and strigolactones in Arabidopsis.” Development, 139(7):1285-1295.

Waters MT, Smith SM, Nelson DC. (2011) “Smoke signals and seed dormancy: Where next for MAX2?” Plant Signaling & Behavior, 6(9):1418-1422.

Nelson DC, Scaffidi A, Dun EA, Waters, MT, Flematti GR, Dixon KW, Beveridge CA, Ghisalberti EL, Smith SM. (2011)"F-box protein MAX2 has dual roles in karrikin and strigolactone signaling in Arabidopsis thaliana." PNASUSA, 108(21):8897-8902.

Nelson DC, Flematti GR, ^UGRiseborough J, Ghisalberti EL, Dixon KW, Smith SM. (2010)"Karrikins enhance light responses during germination and seedling development in Arabidopsis thaliana." PNASUSA, 107(15):7095-7100.

Nelson DC, ^UGRiseborough J, Flematti GR, Stevens JC, Ghisalberti EL, Dixon KW, Smith SM. (2009) “Karrikins discovered in smoke trigger Arabidopsis seed germination by a mechanism requiring gibberellic acid synthesis and light.” Plant Physiology, 149(2):863-873.

BOOK CHAPTERS

 Nelson DC. (2013) “Are karrikin signalling mechanisms relevant to strigolactone perception?” in Parasitic Orobanchaceae, edited by Joel DM, Gressel J, Musselman LJ, 221-230. Springer Berlin Heidelberg.

 Lab Personnel:

Candidates interested in undergraduate, graduate, or postdoctoral research positions can contact David Nelson by email to inquire about current availability. Applications for graduate school admission should be received through the UCR Graduate Division.