Samanta Snigdha, Barman Mritunjoy, Chakraborty Swati, Banerjee Amitava, Tarafdar Jayanta
Department of Agricultural Entomology, B.C.K.V, West Bengal, India.
Department of Plant Pathology, B.C.K.V, Nadia, West Bengal, India.
Heliyon. 2021 Apr 30;7(4):e06906. doi: 10.1016/j.heliyon.2021.e06906. eCollection 2021 Apr.
Fall armyworm (FAW), a recent invasive pest in India is reported to cause significant damage by feeding voraciously on maize and other economic crops from tropical to temperate provinces. It is becoming an arduous challenge to control the pest as it can survive in a wide range of temperature conditions and is already said to develop resistance towards certain insecticides. The small Heat shock proteins (hereafter, sHsps) are known to play an important role in adaptation of insects under such stress conditions. Our present study involved characterization of the three sHsps genes (sHsp19.74, sHsp20.7 and sHsp19.07) which encoded proteins of about 175, 176 and 165 amino acids with a conserved α-crystalline domain. Phylogenetic analysis of deduced amino acid sequences of the three genes showed strong similarity with the other lepidopteran sHsps. The effect of different growth stages on the expression profile of these stress proteins has also been studied and the Quantitative real time PCR (qRT-PCR) analysis revealed that the transcript level of sHsp19.07 and sHsp20.7 were significantly upregulated under extreme heat (44 °C) and cold (5 °C) stress. However, sHsp19.74 responded only to heat treatment but not to the cold treatment. In addition, the expression profile of all three sHsps was significantly lower in the larval stage (5 instar). Chlorantraniliprole treatment resulted in maximum expression of sHsp19.07 and sHsp20.7 after 12hr of exposure to the insecticide. Meanwhile, the same expression was observed after 8hr of exposure in case of sHsp19.74. These results proved that the sHsp genes of were induced and modulated in response to abiotic stress, thus influencing the physiological function leading to survival of FAW in diversified climate in India.
草地贪夜蛾是印度最近出现的一种入侵害虫，据报道，它通过大量取食玉米和其他经济作物，给从热带到温带省份的农作物造成了严重损害。由于它能在广泛的温度条件下生存，并且据说已经对某些杀虫剂产生了抗性，因此控制这种害虫正成为一项艰巨的挑战。已知小分子热激蛋白（以下简称sHsps）在昆虫适应这种应激条件中发挥重要作用。我们目前的研究涉及对三个sHsps基因（sHsp19.74、sHsp20.7和sHsp19.07）的特性分析，这三个基因编码的蛋白质约有175、176和165个氨基酸，具有保守的α-晶状体结构域。对这三个基因推导的氨基酸序列进行系统发育分析，结果显示它们与其他鳞翅目昆虫的sHsps有很强的相似性。研究人员还研究了不同生长阶段对这些应激蛋白表达谱的影响，定量实时PCR（qRT-PCR）分析表明，在极端高温（44℃）和低温（5℃）胁迫下，sHsp19.07和sHsp20.7的转录水平显著上调。然而，sHsp19.74仅对热处理有反应，对冷处理无反应。此外，所有这三种sHsps在幼虫阶段（5龄）的表达谱均显著较低。氯虫苯甲酰胺处理在接触杀虫剂12小时后导致sHsp19.07和sHsp20.7的表达量最高。同时，sHsp19.74在接触8小时后观察到相同的表达情况。这些结果证明，草地贪夜蛾的sHsp基因在非生物胁迫下被诱导和调节，从而影响生理功能，使其能够在印度多样化的气候中生存。
