title: Impact of different temperatures on survival and energy metabolism in the Asian citrus psyllid, Diaphorina citri Kuwayama.
abstract: Temperature influences the life history and metabolic parameters of insects. Asian citrus psyllid (ACP), Diaphorina citri is a tropical and subtropical pest. ACP invaded new regions around the world and threatened the citrus industry as a vector for Huanglongbing (HLB) disease. ACP is widely distributed and can survive high (up to 45 °C) and low temperatures (as low as -6 °C). The precise mechanism of temperature tolerance in ACP is poorly understood. We investigated adult survival, cellular energy balance, gene expression, and nucleotide and sugar-nucleotide changes under the effect of different temperature regimes (0 °C to 45 °C with 5 °C intervals). The optimum temperatures for survival were 20 and 25 °C. Low temperatures of 0 °C and 5 °C caused 50% mortality after 2 and 4 days respectively, while one day at high temperature (40 °C and 45 °C) caused more than 95% mortality. The lowest quantity of ATP (3.69 ± 1.6 ng/insect) and the maximum ATPase enzyme activities (57.43 ± 7.6 μU/insect) were observed at 25 °C. Correlation between ATP quantities and ATPase activity was negative. Gene expression of hsp 70, V-type proton ATPase catalytic subunit A and ATP synthase α subunit matched these results. Twenty-four nucleotides and sugar-nucleotides were quantified using HPLC in ACP adults maintained at low, high, and optimum temperatures. The nucleotide profiles were different among treatments. The ratios between AMP:ATP and ADP:ATP were significantly decreased and positively correlated to adults survival, whereas the adenylate energy charge was increased in response to low and high temperatures. Exploring energy metabolic regulation in relation with adult survival might help in understanding the physiological basis of how ACP tolerates newly invaded regions.
authors.affiliation: Entomology and Nematology Department, Citrus Research and Education Center, IFAS, University of Florida, FL, USA; Department of Plant Protection, Faculty of Agriculture, Tanta University, Tanta, Egypt.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: El-Shesheny
authors.affiliation: Entomology and Nematology Department, Citrus Research and Education Center, IFAS, University of Florida, FL, USA.
authors.forename: Faraj
authors.initials: F
authors.lastname: Hijaz
authors.affiliation: Department of Plant Protection, Faculty of Agriculture, Tanta University, Tanta, Egypt.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: El-Hawary
authors.affiliation: Department of Plant Protection, Faculty of Agriculture, Tanta University, Tanta, Egypt.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Mesbah
authors.affiliation: Entomology and Nematology Department, Citrus Research and Education Center, IFAS, University of Florida, FL, USA. Electronic address: nabilkilliny@ufl.edu.
authors.forename: Nabil
authors.initials: N
authors.lastname: Killiny
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002957:Citrus / Q000469:parasitology; D058639:Cold-Shock Response; D004734:Energy Metabolism / Q000502:physiology*; D018869:Heat-Shock Response; D006430:Hemiptera / Q000378:metabolism* / Q000502:physiology*; D016019:Survival Analysis; D013696:Temperature
chemical_list: D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate
keywords: AMP:ATP ratio; ATP; ATPase; Adenylate energy charge; Diaphorina citri; Nucleotide; Temperature tolerance; hsp 70