The University of Queensland, School of Biological Sciences, St Lucia, QLD, Australia.
King Abdulaziz City for Science and Technology (KACST), Nuclear Science Research Institute (NSRI), Riyadh, Saudi Arabia.
PLoS One. 2018 Apr 19;13(4):e0195349. doi: 10.1371/journal.pone.0195349. eCollection 2018.
Phosphine is the only general use fumigant for the protection of stored grain, though its long-term utility is threatened by the emergence of highly phosphine-resistant pests. Given this precarious situation, it is essential to identify factors, such as stress preconditioning, that interfere with the efficacy of phosphine fumigation. We used Caenorhabditis elegans as a model organism to test the effect of pre-exposure to heat and cold shock, UV and gamma irradiation on phosphine potency. Heat shock significantly increased tolerance to phosphine by 3-fold in wild-type nematodes, a process that was dependent on the master regulator of the heat shock response, HSF-1. Heat shock did not, however, increase the resistance of a strain carrying the phosphine resistance mutation, dld-1(wr4), and cold shock did not alter the response to phosphine of either strain. Pretreatment with the LD50 of UV (18 J cm-2) did not alter phosphine tolerance in wild-type nematodes, but the LD50 (33 J cm-2) of the phosphine resistant strain (dld-1(wr4)) doubled the level of resistance. In addition, exposure to a mild dose of gamma radiation (200 Gy) elevated the phosphine tolerance by ~2-fold in both strains.
磷化氢是唯一一种用于保护储粮的通用熏蒸剂，但由于高抗磷化氢害虫的出现，其长期应用受到威胁。鉴于这种不稳定的情况，有必要确定一些因素，如应激预处理，这些因素会干扰磷化氢熏蒸的效果。我们使用秀丽隐杆线虫作为模型生物，测试了热和冷休克、紫外线和伽马辐射预先暴露对磷化氢效力的影响。热休克显著增加了野生型线虫对磷化氢的耐受性，使其增加了 3 倍，这一过程依赖于热休克反应的主要调节剂 HSF-1。然而，热休克并没有增加携带磷化氢抗性突变的 dld-1(wr4)菌株的抗性，而冷休克也没有改变两种菌株对磷化氢的反应。用 LD50 的紫外线（18 J cm-2）预处理不会改变野生型线虫对磷化氢的耐受性，但 LD50（33 J cm-2）的磷化氢抗性菌株（dld-1(wr4))的抗性增加了一倍。此外，暴露于轻度剂量的伽马辐射（200 Gy）可使两种菌株的磷化氢耐受性提高约 2 倍。
