Paul Hills

I am interested in various aspects of the molecular control of seed germination and plant growth.  Most of my research to date has been on the molecular mechanisms by which thermoinhibition is imposed in Tagetes minuta (Khakibos) achenes.  Thermoinhibition is a fascinating process through which embryos are able to prevent themselves from germinating when the ambient temperature is too high for the seedling to establish successfully.  Unlike thermodormancy, the seeds do not become dormant but are able to germinate immediately when the temperature is reduced below a threshold limit.  As many agriculturally important crop species also become thermoinhibited, an increase in our understanding of the processes involved in thermoinihibition will also be of great benefit to agriculture.  Lately I have been researching the mechanisms by which a number of low molecular weight chemicals, such as acetoin, 2,3-butanediol and smoke, promote germination, seedling establishment and ultimately, plant growth.  I am extremely interested in how model plant species perceive these signals, as well as the resultant changes in gene expression that ultimately lead to increased growth by the plant.  Hopefully, if we can understand these processes fully we can also apply the knowledge to crop plants to increase yield and productivity.

List of Publications

• Taylor, NJ, PN Hills and J van Staden.  2007.  Cell division versus cell elongation: the control of radicle elongation during thermoinhibition of Tagetes minuta achenes.  Journal of Plant Physiology 164: 1612-1625
• Malabadi, RB, PN Hills and J van Staden.  2006.  RAPD assessment of clonal identity of somatic seedlings derived from vegetative shoot apices of mature Pinus patula trees.  South African Journal of Botany 72: 181-183
• Hills, PN, E Balázs and J van Staden.  2005.  Isolation of cDNA clones for genes that are differentially expressed during thermoinhibition in achenes of Tagetes minuta L.  Plant Growth Regulation 45: 83-94
  Taylor, NJ, PN Hills, Gold, JD, WA Stirk and J van Staden.  2005.  Factors contributing to the regulation of thermoinhibition in Tagetes minuta L.  Journal of Plant Physiology 162:  1270-1279
  Hills, PN and J van Staden.  2003.  Thermoinhibition of seed germination.  South African Journal of Botany 69: 455-461
• Hills, PN and J van Staden.  2002.  An improved DNA extraction procedure for plant tissues with a high phenolic content.  South African Journal of Botany 68: 549-550
• Podd, LA, PN Hills and J van Staden.  2002.  Physiological responses and extension of vase life of cut carnation flowers treated with ethanol and acetaldehyde. II. Protein content and enzyme activity.  Plant Growth Regulation  38: 107-117
• Hills, PN, CD Viljoen and J van Staden.  2001.  Differences in polypeptide expression in thermoinhibited and germinating achenes of Tagetes minuta L.  Plant Growth Regulation  34:187-194