TITLE:
Metabolic Changes during Acclimation and Hardening to Heat and Drought Stress in Zaprionus indianus
AUTHORS:
Aditya Moktan Tamang, Ravi Parkash, Raj Kamal Srivastava, Padmasana Singh
KEYWORDS:
Zaprionus indianus, Rapid Heat Hardening, Heat Acclimation, Rapid Desiccation Hardening, Desiccation Acclimation
JOURNAL NAME:
Advances in Entomology,
Vol.10 No.1,
January
26,
2022
ABSTRACT: The survival ability of insects can be limited with the changes in the
levels of energy metabolites under stressful conditions but only a few studies
have considered the plastic effects of heat and related climatic factors
relevant to tropical habitats. The objectives of our study were to determine
whether adults of Zaprionus indianus are capable of rapid heat
hardening (RHH) and rapid desiccation hardening (RDH) and to compare its
benefits with heat acclimation (HA) and desiccation acclimation (DA). Adult flies
reared under season-specific simulated conditions were subjected to 38°C for
RHH and 32°C for HA, while 5% relative humidity (RH) was maintained for RDH and
40% RH for DA. Stress-induced effects of heat and desiccation on the levels of
five metabolites namely cuticular lipids (CL), total body lipids (TBL),
protein, proline, and carbohydrates were then estimated by biochemical method.
Different duration of heat hardening and acclimation led to more accumulation
of CL whereas different durations of desiccation hardening and acclimation
revealed less accumulation. In contrast, there was an accumulation of
carbohydrates and protein under desiccation hardening and acclimation whereas
there was the utilization of carbohydrates and protein under heat hardening and
acclimation. However, mixed results were observed on the level of proline and
TBL under both heat and desiccation stress. These stress-triggered changes in
the levels of various metabolites suggest a possible link between heat and
desiccation tolerance. Hence, these compensatory changes in the level of
various metabolites also suggest possible energetic homeostasis in Z. indianus living under harsh climatic conditions of heat and drought in tropical regions.