Response to water deficit and high temperature of transgenic peas (Pisum sativum L.) containing a seed-specific alpha-amylase inhibitor and the subsequent effects on pea weevil (Bruchus pisorum L.) survival.
The effects of water deficit and high temperature on the production of alpha-amylase inhibitor 1 (alpha-AI-1) were studied in transgenic peas (Pisum sativum L.) that were developed to control the seed-feeding pea weevil (Bruchus pisorum L., Coleoptera: Bruchidae). Transgenic and non-transgenic plants were subjected to water-deficit and high-temperature treatments under controlled conditions in the glasshouse and growth cabinet, beginning 1 week after the first pods were formed. In the water-deficit treatments, the peas were either adequately watered (control) or water was withheld after first pod formation. The high-temperature experiments were performed in two growth cabinets, one maintained at 27/22 degrees C (control) and one at 32/27 degrees C day/night temperatures, with the vapour pressure deficit maintained at 1.3 kPa. The plants exposure to high temperatures and water deficit produced 27% and 79% fewer seeds, respectively, than the controls. In the transgenic peas the level of alpha-AI-1 as a percentage of total protein was not influenced by water stress, but was reduced on average by 36.3% (the range in two experiments was 11-50%) in the high-temperature treatment. Transgenic and non-transgenic pods of plants grown at 27/22 degrees C and 32/27 degrees C were inoculated with pea weevil eggs to evaluate whether the reduction in level of alpha-AI-1 in the transgenic pea seeds affected pea weevil development and survival. At the higher temperatures, 39% of adult pea weevil emerged, compared to 1.2% in the transgenic peas grown at the lower temperatures, indicating that high temperature reduced the protective capacity of the transgenic peas.
Sousa-Majer
Maria José de
MJ
Department of Environmental Biology, Curtin University of Technology PO Box U1987, Perth, WA 6845, Australia. M.Majer@curtin.edu.au
Turner
Neil C
NC
Hardie
Darryl C
DC
Morton
Roger L
RL
Lamont
Byron
B
Higgins
Thomas J V
TJ
D000064:Acclimatization; D000818:Animals; D001517:Coleoptera / Q000472:pathogenicity*; D003890:Desiccation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006358:Hot Temperature; D018532:Pisum sativum / Q000187:drug effects / Q000469:parasitology / Q000502:physiology*; D010935:Plant Diseases / Q000469:parasitology; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000469:parasitology / Q000502:physiology; D012639:Seeds / Q000201:enzymology*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D000516:alpha-Amylases