Heat shock, with recovery, promotes protection of Nicotiana tabacum during subsequent exposure to Ralstonia solanacearum.
Host-pathogen interactions in plants are complex and potentially influenced by heat shock/stress (HS). Host HS proteins (HSPs) induced prior to bacterial exposure may facilitate the folding of newly synthesized defense proteins and promote incompatible host-pathogen interactions. We hypothesized that a non-lethal HS, with recovery, promotes protection of Nicotiana tabacum during subsequent exposure to avirulent soilborne necrotrophic pathogen Ralstonia solanacearum. The objective of this study included investigating the effects of HS with or without recovery on the outcome of bacterial exposure to a virulent and avirulent biovar of R. solanacearum in N. tabacum cell suspensions. This was assessed by quantifying host Hsp70/Hsc70 levels, mitochondrial electron (e (-)) transport activity as a marker of viability, and phosphatidylserine externalization and DNA fragmentation as markers of apoptosis. Our findings support the hypothesis that HS, with recovery, promotes protection of N. tabacum during subsequent exposure to R. solanacearum, suggesting a role for Hsp70/Hsc70 in the observed protection of e (-) transport, increased apoptosis, and DNA fragmentation.
Department of Biochemistry, University of Johannesburg, Auckland Park, Johannesburg, South Africa, hbyth@uj.ac.za.
Heather-Anne
HA
Byth-Illing
Liza
L
Bornman
D017209:Apoptosis; D053938:DNA Fragmentation; D004579:Electron Transport; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response; D008954:Models, Biological; D011523:Protoplasts / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D043368:Ralstonia solanacearum / Q000472:pathogenicity / Q000502:physiology*; D012044:Regression Analysis; D013535:Suspensions; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism* / Q000382:microbiology*; D014774:Virulence
D018840:HSP70 Heat-Shock Proteins; D013535:Suspensions