Huang, ShaomingWarkentin, Tom2020-03-232020-03-232020-03-10http://hdl.handle.net/10388/12720The balance between abscisic acid (ABA) synthesis and catabolism plays an important role in the plant's response towards multiple abiotic stresses including cold, drought and salt stress; however, the connection between ABA homeostasis and plant's heat response is still elusive. We assessed pea leaf ABA biosynthesis and catabolism at different time periods under 38°C among five pea varieties with varying heat tolerance by profiling the concentrations of ABA and its five key ABA catabolites from the four major ABA metabolic pathways via liquid chromatography-multiple reaction monitoring assay. More ABA accumulated in the ABA metabolism pool at high temperature condition compared to normal temperature; the ABA response started immediately after 3 hour. Heat tolerant varieties had a higher ABA synthesis and turnover rate at high temperature, than their respective heat susceptible counterparts. Further we valida ted that pea ABA responsive protein genes (ABR17 & ABR18) did not relate to the ABA induction above-mentioned. Identification of the key gene for the heat-induced ABA response still remains to be done for a better understanding on ABA's role in heat response, as well as the responsive variation between heat tolerant and sensitive varieties. This study aids in understanding the impact of a warming summer on the pea plant in the perspective of hormone regulation, and gives a new direction to perceive the different heat tolerance among Canadian pea varieties.enAttribution-NonCommercial-NoDerivs 2.5 Canadafield peaABAshort term heat stressfloweringheat stresshomeostasisPisum sativumheat responseABA responsive genesPresentation